PROCEEDINGS

OF

THE SECOND EASTERN NATIVE GRASS SYMPOSIUM

HELD IN

BALTIMORE, MARYLAND

NOVEMBER 17-19, 1999

TECHNICAL EDITS BY

JERRY C. RITCHIE

JOHN A. DICKERSON

CAROLE A. RITCHIE

EDITS AND FRONT COVER DESIGN BY

LINA UNDAYAG

HOSTED BY

USDA NATURAL RESOURCES CONSERVATION SERVICE

USDA NRCS PLANT MATERIALS PROGRAM

USDA AGRICULTURAL RESEARCH SERVICE

NATIONAL ASSOCIATION OF CONSERVATION DISTRICTS

PUBLISHED BY

AGRICULTURAL RESEARCH SERVICE

NATURAL RESOURCES CONSERVATION SERVICE

Beltsville, Maryland

May 2000
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

-iiPreface

The Second Eastern Native Grass Symposium was held in Baltimore, MD during November,

1999. The Symposium provided 70 presentations, comprised of invited and volunteer oral

presentations and poster papers. Presented here are the written papers or abstracts of the

papers presented.

Native grass use is expanding as rapidly as the seed and plant supplies of eastern sources will

allow. The recent demand for materials is being driven by both a desire to utilize native plants to

meet resource conservation objectives, and additional discovery of valuable functions which

native grasses bring to discreet habitats and the environment in general. Native grasses bring a

host of valuable traits to the conservation effort. Relatively unknown, under-appreciated, underresearched, and therefore under-used, native grasses will play a powerful role in environmental

improvement as use technology is developed and institutionalized.

It was the goal of the co-chairs and the program committee to organize the Symposium to be as

all encompassing of native grass interests as 21⁄2 days would permit. The decision to publish the

technical Proceedings was a response to the view of participants that the presented technology

will be indeed very valuable to their diverse activities. We also feel that it will be valuable to

extend the information to those who could not attend the Symposium.

The Symposium received tangible support from the Natural Resources Conservation Service and

the Agricultural Research Service, both of USDA. Ernst Conservation Seeds, Inc. also

generously supported the Symposium. The National Association of Conservation Districts,

Conference Services was extremely helpful in planning and providing registration support at the

conference.

This Proceedings documents a baseline of knowledge, and an overview of action regarding

native grass use as we begin a new century. The use of native grasses and grasslands will

increase in scale and sophistication. It was our pleasure to assemble this record from the

Symposium and we would like to thank the authors for their support.

Jerry C. Ritchie, ARS

John Dickerson, NRCS

Gwen C. Meyer, NRCS

For additional information on Eastern Native Grasses, or for an electronic copy of this publication,

please visit our web sire at: "http://www.nhq.nrcs.usda.gov/BCS/PMC/eng/eng.html"

This publication should be cited as:

Ritchie, J.C., J.A. Dickerson, and C.A. Ritchie (eds.). 2000. Proc. Second Eastern Native Grass

Symposium: Baltimore, MD November 17-19, 1999. Published by USDA-Agricultural Research

Service, and USDA-Natural Resources Conservation Service, Beltsville, MD. 370 p.

Published as Agricultural Research Service, Hydrology Lab, Occasional Paper #2000-1

The United States Department of Agriculture (USDA) prohibits discrimination in all its programs on the basis

of race, color, national origin, gender, religion, age, disability, political belief, sexual orientation, and marital

or family status. To file a complaint of discrimination, write the USDA, Director, Office of Civil Rights, Room

326W, Whitten Building, 14th and Independence Avenues, SW, Washington, D.C. 20250-9410 or call (202)

720-5964 (voice or TDD). USDA is an equal opportunity provider and employer.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

- - iii

DEDICATION

Dr. Ronald S. Schnabel

The Symposium Proceedings are

dedicated in the memory of

Dr. Ronald S. Schnabel,

who was a Soil Scientist for the

USDA-Agricultural Research Service,

Pasture Systems and Watershed

Management and Research Lab,

University Park, Pennsylvania.

Ronald R. Schnabel’s areas of expertise

included adsorption-desorption kinetics,

N transformation processes and

field measurement methodology.

His research interests included impacts of

riparian ecosystems on quality of agricultural

drainage, and effect of near-stream

management on nutrient

export from the watershed.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

-ivTable of Contents

Author(s)

Title

Page

Horn, F.

Agricultural Research Service Activities Pertinent to the Eastern Native Grass Symposium

1

Teels, B.M.

Native Grass Technology: A Brief History, Its Spin-Offs and Refinements and Where It May Be Headed in the

East

7

Frost, C.

Native Grasses and Grasslands in the Presettlement Landscape of Eastern North America

10

Poole, W.R.

Seed Production: How Much of What, By Whom?

11

Panciera, M.

Native Grass Establishment: Pitfalls and Potentials

14

Carroll, D. and F. Knowlton

Native Grass Management

25

Frye, C.T.

Non-Native Genotypes and Outbreeding Depression in Plants: Theoretical and Empirical Issues

26

Steele, O.

Native Grasslands and Their Wildlife Value in Southern Ontario Landscapes

44

Schnabel, R.R.

Improving Water Quality Using Native Grasses

46

Diboll, N.

Landscape and Design Issues With Natives

55

Bowen, B.

Ecosystem Restoration May Prairie State Natural Area

57

Taylor, R.W.

Native Warm-Season Perennial Grasses: The Unrealized Potential as a Forage Crop

58

Barkworth, M.E., K.M. Capels and L.A. Vorobik

A Grass Manual for North America

90

Beeler, J.

Cades Cove Meadow and Wetland Restoration

91

Burgdorf, D., P. Koch and T. Bush

Sweetgrass Propagation Project

94

Burns, J.C. and D.S. Fisher

Forage Potential of Switchgrass and Eastern Gamagrass in the Eastern Piedmont

95

Bush, T.

Revegetating Slag Refuse Areas with Native Warm Season Grasses

103

Calabria, J.

Applied Native Grass Restoration Projects in Western North Carolina

112

Douglas, J.L., S.D. Edwards and D.J. Lang

Estimating Digestibility in Eastern Gamagrass

113

Douglas, J.L., J.M. Grabowski and B.C. Keith

A Comparison of Seed Cleaning Techniques for Improving Quality of Eastern Gamagrass Seed

117

Edwards, S., J. Douglas and H. Bloodworth

Clipping Effect on Yield and Quality of Eastern Gamagrass, Switchgrass, and Bermudagrass

121

Englert, J.

New and Upcoming Native Grass Releases from the Eastern US Plant Materials Centers

127

Ernst, C.L.

Is Growing Native Seeds for Me? The Who, What, When, Where and Why

135

Fairbairn, C.A., G.A. Jung, and L.D. Hoffman

Extending The Grazing Season In Southeast Pennsylvania

136
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

- - v

Gifford, N.A.

Albany Pine Bush Native Plant Restoration Project: Attractive Alternatives Help Protect a Rare Ecosystem

139

Glennon, R.

Transfer Of Technology On Native Grasses

140

Glennon, R.

NRCS National Practice Standard for Vegetative Barriers

141

Grabowski, J.M.

Wildflower Seed Production at the Jamie L. Whitten Plant Materials Center

142

Grabowski, J.M. and J.L. Douglas

Treatments to Overcome Dormancy of Eastern Gamagrass Seed

148

Henson, J.F., D. Pyke, R.E. Riggins, K. Ticknor, J.R. Patterson, and P.H. Smith

Selecting Native Plants Using Vegspec: A Web-Based System

158

Huff, D.R., A.J. Palazzo, M. van der Grinten, and T. Lent

DNA Marker Variation Within and Among Populations Of Native and Commercial Little Bluestem

162

Karrfalt, R.P.

Extraction and Germination Ecology of Twelve Native Grasses from Western North Carolina.

163

Kiniry, J.R., H. Sanchez, J. Greenwade, E. Seidensticker, J.R. Bell, F. Pringle, G. Peacock Jr., and J. Rives

Simulating Biomass/Forage Production of Eastern Gamagrass, Switchgrass, and Other Warm Season Grasses

167

Kiniry, J.R., C.R. Tischler, and G.A. Van Esbroeck

Leaf Area Production, Biomass Production, and Biomass Partitioning for Eastern Gamagrass, Alamo

Switchgrass, and Two Other C4 Grasses

173

Krizek, D.T., M.J. Camp, S.R. Maxon, G.C. Meyer, J.C. Ritchie, K.M. Davis, and M.L. McCloud

Comparative Germination of 1998 and 1999 Lots of Germtec IITM Treated Eastern Gamagrass Seed After 28

Days in the Greenhouse and Laboratory

182

Krohn, A.

Cool Season Natives Common to Southeastern Riparian Areas

194

Kwong, O.

Plant Conservation Alliance

198

Lorenz, D.G.

Army Training Lands - The Native Perspective

200

Masters, R.A., D.D. Beran, F. Rivas-Pantoja, and R.E. Gaussoin

Developing Integrated Weed Management Strategies to Restore Great Plains Grasslands

204

Matthews, C. and J.F. Matthews

Piedmont Prairie Restoration in the Charlotte, NC Area

208

McLaughlin, S.B. and M.E. Walsh

Developing and Evaluating Switchgrass as a Bioenergy Crop

209

Meyer, G.C., N.C. Melvin III,T.R. Turner and H.J. Swartz

Native Warm-Season Grass Establishment as Affected by Weed Control in the Maryland Coastal Plain

212

Miller, C.F. and J.A. Dickerson

The Use of Native Warm Season Grasses for Critical Area Stabilization

222

Morris, D.P.

Surface Mining Reclamation Revegetation Guide

229

Morrison, D.

Grasses and Other Native Plants in Designed and Managed Landscapes

230

Owens, L.B. and D.L. Hothem

Carbon Stored in Soils under Eastern Grasslands

231

Palazzo, A.J., T. Cary, and T. Lent

Rehabilitation of Sandy Soils with Native Species in the Northeast United States

235

Parrish, D.J., D.D. Wolf, P.R. Peterson, and W.L. Daniels

Managing Switchgrass as Biofuels Feedstock

236

Parrish, D.J., D.D. Wolf, P.R. Peterson, and W.L. Daniels

Successful Establishment and Management of Switchgrass

237
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

-viPerry, M.C., P.C. Osenton, G.A. Gough, Edward, and J.R. Lohnes

Establishment of Warm-season Grasses With and Without the Use of Compost Soil Amendments

244

Perry, M.C., and A.S. Deller

Effect of Two Long-term Mowing Regimes on Vegetation

249

Peterson, P.R., S.J. Hutton, A.O. Abaye, D.D. Wolf, and G.B. Benson

Eastern Gamagrass Responses to Defoliation Management

253

Pfaff, S. and M.A. Gonter

Direct Seeding native Species on Reclaimed Phosphate-Mined Lands

259

Pollard, L.

Increasing Establishment Success of Native Grasses – Matching the Techniques with the Equipment

268

Reeves, J.B. III, D.T. Krizek, C.D. Foy, and J.C. Ritchie

Comparative Biomass, Composition, and Forage Quality of Greenhouse-grown Gamagrass Plants Differing in

Age, Stage of Development, and Drought Tolerance

269

Rhoden, E.G., J.C. Ritchie, D.T. Krizek and C.D. Foy

Vegetative Propagation of Eastern Gamagrass: Effects of root pruning and growth media

270

Rhoden, E.G., J.B. Reeves, III, J.C. Ritchie, and D.T. Krizek and C.D. Foy

Influence of Root Removal on Regrowth and Forage Quality of Greenhouse-Grown Eastern Gamagrass

276

Ritchie, J.C., W.D. Kemper, J.M. Englert and D.T. Krizek

Grass Hedges for Erosion Control

283

Salon, P.R. and C.L. Dewald

Eastern Gamagrass Breeding in New York and Oklahoma

290

Salon, P.R. and D.J.R. Cherney

Eastern Gamagrass Forage Quality as Influenced by Harvest Management

298

Salon, P.R. and M. van der Grinten

Eastern Gamagrass Response to Accent (nicosulfuron), Basis (rimsulfuron), and Plateau (imazapic) Herbicides

in Comparison to a Few Common Corn Herbicides

305

Salon, P.R. and E.D. Earle

Chromosome Doubling and Mode of Reproduction of Induced Tetraploids of Eastern Gamagrass

311

Sanders, S. and USDA NRCS Florida Plant Materials Center Staff

Beach Dune and Critical Area Stabilization with Native Plants

312

Seamon, G.S., M.J. Hattenbach, A. Cox, and D.R. Gordon

Development of Direct Seeding Techniques to Restore Native Groundcover in a Sandhill Ecosystem

313

Staver, K.W.

Production and Nutrient Uptake by Native Warm-Season Grasses

314

Swartz, H.J., G. Meyer, J. Kujawski, N. Melvin, J. Englert, C. Miller, B. Skaradek, and V. Hopkins

Mid Atlantic Region Grass Collections Efforts at the University of Maryland in Support of the NRCS-PMCs

318

Tischler, C.R., J.D. Derner, and W.R. Ocumpaugh

Improving Seedling Establishment by Modifying Seedling Photomorphogenic Characteristics of Warm-Season

Grasses

322

Tyndall, R.W.

Restoration of an Indigenous Serpentine Grassland and Oak Savanna Ecosystem in Maryland

327

van der Grinten, M. and L.L. Gregory

Vegetated Erosion Control Mats for Site Stabilization

328

van der Grinten, M., J.H. Connery L.L. Gregory and J. Dickerson

Native Plants For National Parks

330

Washburn, B.E. and T.G. Barnes

Converting Tall Fescue Grasslands to Native Warm-Season Grasses

331

Appendix A

Alphabetic List of Common Names of Plants

342

Appendix B

Alphabetic List of Scientific Names of Plants

346

Appendix C

List of Attendees

350

Appendix D

Program Committee

360
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

1

Agricultural Research Service Activities Pertinent to the Eastern Native

Grass Symposium

Dr. Floyd P. Horn1

Administrator, ARS

Introduction

The USDA Agricultural Research Service (ARS) conducts native grass research within its new

National Program for Rangeland, Pastures, and Forages, one of 23 such national programs

within ARS (Table 1).

The mission of this program is to develop and transfer economically sustainable technologies and

integrated management strategies for the nation’s rangeland, pasture, and forage resources. To

conserve and enhance these diverse natural resource bases, these technologies and strategies

must be based on fundamental knowledge of ecological processes and agronomic practices.

This research is conducted by 127 scientists at 47 ARS locations around the United States. ARS

is uniquely situated to provide national leadership in research to understand and manage our

nation’s rangeland, pasture, and forage resources. The 47 locations represent the major climatic

regions and biomes (Figure 1). Their geographic distribution, their inherent land resources, their

ties to major land grant institutions, and their long history of scientific investigation make them

invaluable.

Planning the National Research Program

ARS uses a customer-focused workshop and a subsequent participatory research planning

meeting to identify the vision, mission, research components, and specific problem areas for this

national program to address.

The workshop for rangelands, pastures, and forage was held in Kansas City, Missouri, in

September 1999. More than 80 customers, partners, and stakeholders--representing producers,

industry, environmental groups, non-government organizations, universities, state agricultural

experiment stations, federal stewardship agencies, the USDA Natural Resource Conservation

Service (NRCS), and other government agencies--interacted with more than 70 ARS scientists,

administrators, and staff to identify key issues. The high priority research components identified

at that workshop reflect the needs of this diverse clientele, and the specific research problem

areas focus on some of the most important research needs. The six components are: (1)

ecosystems and their management, (2) plant resources, (3) grazing and the environment, (4)

forage management, (5) integrated pest management, and (6) integrated farming and ranching

systems.

Some specific research identified at the workshop that are related to native grasses, included (i)

improving characteristics that limit native plant growth and development; (ii) improving native

forages for livestock production; (iii) developing DNA fingerprinting techniques to characterize

important native plants; and (iv) identifying ecological processes important for sustainable use of

native grasslands.

After the workshop, writing teams--composed of ARS scientists and the ARS National Program

Team--wrote an action plan. It was reviewed by all ARS scientists whose programs could make

significant contributions. The plan will be available for public review and comment soon at

http://www.nps.ars.usda.gov/ programs/nrsas/ 205/ACTionplan/.

 

1

 Administrator, USDA Agricultural Research Service, Washington, D.C.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

2

More specific research project plans will then be developed at all participating research locations.

These 5-year plans will be subjected to a thorough peer review process involving evaluation

primarily by scientists outside of ARS. These projects will be revised accordingly and then

implemented. The same cycle will be repeated every 5 years. In this way, ARS can continually

use focused input from beneficiaries and critical evaluation by eminent scientists.

Beneficiaries of the National Research Program

ARS research benefits ranchers who use both harvested and grazed forages. It benefits the

action agencies that serve these ranchers, such as NRCS and the Cooperative Extension

Service. Others include federal land stewardship agencies responsible for the nearly 1 billion

acres of publicly owned lands across the Nation such as the Bureau of Land Management, the

Forest Service, the National Parks Service, the Fish and Wildlife Service, the Bureau of Indian

Affairs, and the U.S. Geological Survey. It also benefits state land management agencies

responsible for state owned grazinglands, resource managers, policymakers, and both rural and

urban community organizations with rangeland resources. The public at large benefits through

improved resource conditions associated with our Nation’s grazinglands and their inherent

watershed and wildlife habitat values.

A large part of the rangeland, pasture, and forage programs benefits small farms. There are

major efforts on grazingland management and improvement, forages, and decision support

systems for small farms at several locations including the Dale Bumpers Small Farm Research

Center in Booneville, Arkansas and the Appalachian Farming Systems Research Center near

Beaver, West Virginia. These two locations are researching economic and sustainable forage

and livestock production systems for small family farms in hill lands.

At Beaver, West Virginia, ARS scientists are working with Virginia Tech and West Virginia

University to develop complete grass-based beef production systems for small farms using native

pastures in the Appalachian hill lands. At University Park, Pennsylvania, ARS ecologists and

agronomists are working with producers throughout the northeast to evaluate the roles of plant

species diversity to increase the sustainability of grazinglands in the northeast. Ecologists, soil

scientists, and animal scientists in Watkinsville, Georgia, are researching how sustainable grazing

systems affect soil biochemical properties, nutrient distribution in pasture soils, and soil microbial

diversity.

Currently, the ARS national program staff is assessing each of its approximately 1,200 research

projects--including those involving native grasses--for their relevance to small farm needs. The

results will be available this year.

Other Examples of ARS Research Related to Eastern Native Grasses

As stated in the introduction, ARS maintains a large national program of research related to

native grasses for use in hay, pasture, and natural systems. A few other examples follow:

ARS scientists in Lincoln, Nebraska, are developing improved cultivars of switchgrass, big

bluestem, Indiangrass, Canada wildrye and other native grasses. Their research has shown that

a 1% unit increase in forage digestibility can increase stocker weight by 3.2%. Most of these

improved native grasses are adapted to the eastern U.S. The Lincoln scientists are also at the

forefront of developing switchgrass for use as a bioenergy crop to produce ethanol from biomass

or for combustion in power plants to produce electricity.

ARS scientists also work closely with many of the Plant Materials Centers maintained by NRCS in

evaluating new sources of native plants. ‘Pete’, a commercial eastern gamagrass cultivar, came

from the Plant Material Center at Manhattan, Kansas, working closely with ARS scientists at

Woodward, Oklahoma.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

3

Scientists in Raleigh, North Carolina, have developed techniques for establishing and using

eastern gamagrass for grazing, hay, and silage. Scientists in Columbia, Missouri, are evaluating

alternative cropping systems using eastern gamagrass to increase water infiltration and water use

efficiency.

At Woodward, Oklahoma, ARS scientists are working to select, characterize, and map genes

controlling apomixis in eastern gamagrass and to develop ways to transfer the eastern

gamagrass genes to corn and other grasses. Many of the current cultivars of eastern gamagrass

have their origins from the research at Woodward.

ARS scientists in Beltsville, Maryland, are evaluating native grasses for use in producing high

quality forage, improving acid, compact horizons of marginal soils, and creating buffer strips

around cropland and along streams to reduce soil loss and movement of sediment and nutrient

into stream channels.

A team of ARS scientists working with NRCS has shown that native grasses can be used in

narrow grass rows to reduce soil loss from agricultural fields. The NRCS working with ARS

scientists have developed a " Conservation Practice Standard on Vegetative Barriers" for use by

NRCS on farms.

ARS scientists in Temple, Texas, have developed methods for improving warm season grasses

focussing on seedling establishment, nutrient quality, forage production and biomass for energy

production.

Summary

Native grasslands in the U.S. are a unique resource and pose unique challenges for

management, use, and conservation. ARS directs research to develop and transfer methods and

strategies to maintain the strong rangeland, pasture, and forage research effort required to meet

these challenges and to provide more efficient ways to manage these lands and ensure that they

continue to play a role in sustainable plant and animal agricultural systems.

Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

5

Table 1. List of the Agriculture Research Service National Programs. More details on these

programs can be found at http://www.nps.ars.usda.gov/programs/table.cfm

Animal Production, Product

Value and Safety

Natural Resources and

Sustainable Agricultural

Systems

Crop Production,

Product Value and

Safety

101 - Animal Genomes,

Germplasm, Reproduction &

Development

201 - Water Quality and

Management

301 - Plant, Microbial,

and Insect Genetic

Resources, Genomics

and Genetic

Improvement

102 - Animal Production

Systems

202 - Soil Resource

Management

302 - Plant Biological and

Molecular Processes

103 - Animal Health 203 - Air Quality 303 - Plant Diseases

104 - Arthropod Pests of

Animals and Humans

204 - Global Change 304 - Crop Protection and

Quarantine

105 - Animal Well-Being &

Stress Control Systems

205 - Rangeland, Pasture and

Forages

305 - Crop Production

106 - Aquaculture 206 - Manure and

Byproduct Utilization

306 - New Uses, Quality,

and Marketability of Plant

and Animal Products

107 - Human Nutrition 207 - Integrated Farming

Systems

307 - Bioenergy and

Energy Alternatives

108 - Food Safety (animal &

plant products)

308 - Methyl Bromide

Alternatives
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

6

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Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

7

Native Grass Technology: A Brief History, Its Spin-offs and Refinements

and Where It May Be Headed in the East

Billy M. Teels1

Director, USDA, NRCS, Wetland Science Institute

Of all the plants, the grasses are the most important to man. All our breadstuffs (corn, wheat,

oats, rye, and barley), rice, and sugarcane are grasses. Our lawns of Kentucky bluegrass and

fescue are grasses, as well as the majority of our pasture and range plants. Grasses have been

so successful in the struggle for existence that they have a wider range than any other plant

family. They occupy nearly all parts of the earth and far exceed any other in the total number of

individuals (Chase 1948).

Native grasses have long been appreciated and utilized on this continent. Native Americans

understood the relationship of grass and buffalo and helped maintain the open prairie with fire. It

is originally thought that about 700 million acres in the United States were covered with grass

(Wooten and Barnes 1948). The grasslands of the tall-grass prairies also formed the largest

single block of highly productive soils in North America. As a result, nearly 250 million acres of

that grassland have been plowed up and planted in crops or pasture. Although most of the tallgrass prairie has been converted, much of the mixed- and short-grass prairie still remains.

Since the turn of the century much has been done, especially in the prairies, to understand how

native grasses grow and respond to management. Research and observations over the past

century have formed a significant body of knowledge that contribute to a successful, modern

native grass industry and an ever growing native grass technology that supports it. J.E. Weaver

at the University of Nebraska conducted some of the first work on native grasses. Weaver

demonstrated that native prairie flora was much more drought-resistant than the agronomic flora

which has largely supplanted it. He found that the diversity of grass species that formed the

native prairie practiced “team work” underground by distributing their root-systems to cover

multiple depths to utilize and conserve moisture, whereas the roots of agronomic plant species

were confined to a single level without such interaction.

Early range conservationists recognized that native grasses also produced highly nutritious and

palatable forage, particularly the dominant species associated with climax grass communities.

Not only were those grasses valuable for livestock, but, because they evolved as part of the

prairie ecosystem, they were also extremely well adapted and could be easily maintained with

proper grazing. Early range conservationists also recognized that continuous removal of foliage

by grazing could lead to declining range condition resulting in a reduction in both the production

and quality of forage. Accordingly, they devised an ecologically based classification system that

rated the condition of rangeland based on the degree that a plant community deviated from the

preferred climax stage. Reference conditions, known as range sites, were then developed for

each soil association that supported a different climax community. The species composition and

productive capacity for each range site were then characterized from clipping data to provide a

benchmark, or measure, against which the condition of any plant community could be compared.

This system allowed early range conservationists to assist landowners with the management of

native grasses--to reduce grazing pressure when range condition was at a low or declining state

or to prescribe livestock stocking rates that were in keeping with the capacity of the land.

It followed that if native grasses could be managed under such a scenario, then they could also

be established under the same concept. Knowledge of the species composition for each range

site allowed the development of seeding mixtures that were designed specifically for the site.

This technique enabled the planting of a diverse and natural plant community that matched the

 

1 Director, USDA, NRCS, Wetland Science Institute, 11400 American Holly Drive, Laurel, MD
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

8

site’s capability with species known to thrive there under natural conditions, which in turn helped

ensure a successful establishment.

However, merely knowing the plant species that are best suited to a particular site by no means

guarantees success. Many obstacles had to be overcome before the first native grass plantings

could become reality. For example, most climax plant communities are composed of an array of

species, meaning that plantings would necessarily have to include a mixture of seeds from

different species. Although the plantings could concentrate on the dominants of the climax

communities, there were still many problems to overcome such as; how to harvest the seeds of

species that grew at different heights, how to collect seeds from species that fruited at different

times of the year, and how deal with the many differences in species’ growth habitats and biology.

That challenge must have seemed overwhelming to the early plant material specialists who were

confronted with the problem. But all those problems were addressed. Seeds were collected and

planted in single species blocks so that their progeny could be uniformly harvested and then put

in a mix with other species that were treated similarly. Seed cleaners were developed to reduce

the hairs, plumes, and bristles that are so common to native grasses. Certified seed testing

programs to address seed purity were developed, so that landowners would know how many

pounds of pure live seed they were actually getting with their purchases. The USDA, SCS Plant

Materials Program developed and released varieties of many native grass species and

encouraged their commercial production for the large-scale plantings which were to follow.

The seed production and agriculture industries also contributed significantly to the early

technology. For example, conventional grain drills were incapable of passing the small, light

seeds that are characteristic of native grass species; so planters were developed specifically for

native grasses that were capable of distributing and planting seed at the appropriate spacing and

depth. Native grasses are also characteristically slow growers and often succumb to the

competition of weeds, so many agronomic practices were developed for weed control to provide

opportunity for native grass stands to grow and mature with reduced competition. These and

other technological developments helped give the practice of native grass planting a sound

footing upon which many landowners relied to plant thousands if not millions acres of worn out

fields and abandoned cropland to healthy stands of native grass. The conservation programs

that followed the dust bowl, the Soil Bank Program, the Great Plains Conservation Program, and

others provided added incentives to the practice through both technical and financial assistance.

In addition to the early technological advances, other developments have followed and still

continue to occur. For example, Jacobson in 1981 introduced the concept of sculpturing

plantings to hydrologic gradients, which made the practice of establishing native grasses valuable

not only for restoring rangeland but for restoring wetlands as well. The recognition that the seed

of certain grass species could not be moved beyond a certain distance from their original point of

collection was important in the Plant Materials Program developing cultivars that were much more

locally adapted. Improvements have been made in all aspects of seed cleaning, testing, storage,

and harvesting occurred, as well as advances in planting and weed control. Now, chemicals can

accomplish in a few hours what once required a half-year of culture and applied agronomy.

Additionally, the recognition of benefits of native grasses, especially the warm-season species,

has now become widespread. Warm-season native grasses are currently promoted in nearly

every State and Federal conservation program, not only for the diverse natural cover that they

provide but also for their benefits to multiple species of wildlife. Accordingly, the demand for

native grass seed has grown exponentially and has expanded well beyond the prairie where the

industry had its beginnings.

Because the use of native grasses is relatively new to some regions, advocates may not be

aware of all the associated technology. Without such knowledge, mistakes can be made in

planting or management that will severely compromise the benefits that native grasses can

provide. For example, seeds from the Midwest may be purchased and transported over vast

distances without knowing their geographic limits. Plantings may occur on sites where little is

known about the species that would grow there naturally. Tried and proven techniques for
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

9

planting or weed control may be ignored. Attention to these details is important if native grasses

are to be successfully grown.

The fact that you are holding this symposium demonstrates that you care about the science and

technology associated with native grasses as well the grasses themselves. This symposium

offers a forum for the exchange of ideas and information that will be valuable in spreading that

technology. The recognition that a significant body of knowledge already exists will be important

in that cause. Although the East will certainly have technological needs that are uniquely its own,

we do not need to reinvent the wheel with every problem. Much has been learned that could be

successfully applied if only there was an awareness of the technology.

References

Chase, A. 1948. The meek that inherit the earth. In United States Department of Agriculture.

Grass, the Yearbook of Agriculture 1948. U.S. Government Printing Office. Washington, D.C. 8-

15.

Wooten, H. H. and C. P. Barnes. 1948. A billion acres of grasslands. In United States

Department of Agriculture. Grass, the Yearbook of Agriculture 1948. U.S. Government Printing

Office. Washington D.C. 25-34.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

10

Native Grasses and Grasslands in the Presettlement Landscape of Eastern

North America

Cecil Frost1

Before European settlement, the landscape of eastern North America supported a rich diversity of

grasslands and woodlands with a well-developed herb layer in nearly every physiographic

province and latitude. Today’s remnants likely represent only 1-3% of the original extent and

variety. Prairies and pyrophytic woodlands with sparse tree cover were exploited for grazing and

farming immediately upon settlement. Wetter areas, although grazed, persisted until after

exploitation of uplands was complete. Some were drained in the Colonial era but most persisted

until passage of legislation in the late 1800s facilitated wetland drainage, which then escalated

throughout the 20th century. In plant communities having a dominant herb layer, grasses were

favored in the drier, sunnier locations while forbs dominated in moister, shadier locations.

Original habitats where grasses were dominant seem to have been those with the following

conditions: drier soils, wet saline marsh soils, xeric sites like ridges and dry south slopes, sites

with soil conditions stressful to plant growth, such as serpentine barrens and places where soils

feather out onto rock outcrops and ledges. Even where woody succession was retarded by thin

soils, phytotoxic soils, excessively xeric, or excessively wet conditions, fire seems to have been

required for maintenance of all eastern grasslands, with exception only of brackish and salt

marshes. Most species diversity, including most rare species, is found in the herb layer.

Exclusion of fire from natural communities has led to development of multistoried woody

vegetation and consequent depauperization of the herb layer in all but a few mesic, nonpyrophytic types like cove hardwood and northern beech-maple forests. Loss of the species-rich

grass-forb layer throughout eastern North America is an ecological catastrophe still largely

unrecognized.

Reference

Frost, C. C. 1998. Presettlement fire regimes of the United States: a first approximation. Pages

70-81 in T.L. Pruden and L.A. Brennan (eds.). Fire in ecosystem management: shifting the

paradigm from suppression to prescription. Tall Timbers Fire Ecology Conference Proceedings,

No. 20. Tall Timbers Research Station, Tallahassee, FL.

 

1

 North Carolina Plant Conservation Program, Raleigh, North Carolina
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Seed Production: How Much of What, by Whom?

W. R. (Bill) Poole1

The mandated use of native species for some applications, program criteria that encourage their

use in others and increasing public interest in native species plantings are all helping fuel the

demand for native seed. Meeting that demand presents both opportunities and challenges for the

native seed industry. Opportunities and challenges that can be summarized in three questions:

How much? What species? By whom? Regardless of how you answer those questions – and

maybe we’ll start with the last one first – successful native plantings start with quality seed. While

seed quality is a prerequisite, your choice of seed source is very likely to be determined by your

planting objectives.

If your objective is to restore a piece of native prairie you’re likely to be looking for as wide a

range of species as you can possibly get. At least in the part of the country I’m most familiar with,

those plantings are usually on relatively small areas, often in an urban setting and intended to

serve both public education and conservation functions. In those situations, locally collected wild

harvest seed is usually seen as being the most suitable source of plant material. That same

source may be your only option if there’s a mandated requirement to use local-source seed as,

for example, is sometimes the case when disturbed sites have to be revegetated in areas like

national parks.

If, on the other hand, your objective is to reclaim a gravel pit in Vermont you may well choose to

use a mix of native species cultivars that have variety characteristics suited to the very limited

range of site conditions you’re dealing with. A cultivar, or mix of cultivars, might also be the

preferred choice if your objective is to establish a native species planting for a specific use like

summer grazing in central New York. In planting situations where you’re facing very uniform site

conditions or a specific use objective, the higher level of “predictability” inherent in cultivars may

make them your most suitable plant material choice.

In short, I believe the answer to the question “Seed production by whom?” is “Everyone”. As the

demand for native species plant material grows, and as planting objectives become more diverse,

we’ll continue to need increasing amounts of both wild harvest and cultivar seed. As has been

recognized by seed certifying agencies in both Canada and the US, there is also a need for

native seed classes that have characteristics somewhere between “wild harvest” and “cultivar”.

Much of the impetus for the consideration of those changes in Canada was initiated by Ducks

Unlimited. So you won’t think I’m immodest when I say that, I should perhaps tell you a little bit

about Ducks Unlimited Canada’s use of native species plant material and how our interest in the

seed production industry developed. That background also leads us into the question “Seed

production of what species?” - - at least from our agency’s point of view.

Although precise statistics aren’t available, I don’t think there’s any doubt that Ducks Unlimited

has been the largest single user of native species plant material in Canada over the past twelve

or fifteen years. Our primary objective in making those plantings has been to provide habitat for

waterfowl and other wildlife species. I won’t say much more than that about wildlife considerations

and I’ll limit most of my remarks to our experience in the Canadian prairie provinces.

Because we were planting fairly large acreages and because there was virtually no native seed

production in Canada at the time, we really had only one source of seed at the outset; a relatively

limited number of adapted cultivars that had been developed in the US Northern Great Plains.

Almost all of those first plantings were simple mixes of only three or four species of straight coolseason or straight warm-season grasses.

 

1 Agologist, Ducks Unlimited Canada, Box 1160, Stonewall, MB. R0C 2Z0
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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When we began delivering programs under the North American Waterfowl Management Plan in

1989, our habitat emphasis shifted much more toward the provision of nesting cover plantings on

previously cultivated uplands associated with wetlands. Suddenly we were faced with the

challenge of planting 10,000 acres or more per year on very diverse – and often somewhat

unproductive – sites.

It very quickly became evident that there were two major shortcomings in our program. Firstly, the

range of species we had available was too limited to formulate mixtures for the wide array of

range sites we were encountering. In addition, our planting techniques needed to be revised to

allow us to better place those mixtures on the range sites to which they were adapted. Unless

those shortcomings were addressed, we couldn’t fully realize the biodiversity benefits we felt

native species plantings should give us.

To deal with the shortage of sufficient numbers of adapted species, we initiated what has become

known as an ecovarTM development program in cooperation with a number of Canadian federal

agriculture research stations, two universities and the NRCS in 1991. Since that time, 19 grass, 9

forbs and 3 shrub species have been entered in the program. A listing of the species in the

program at this time appears at the end of this paper.

An ecovarTM, or ecological variety, may share some characteristics with both what is now known

as Source Identified and Selected plant material in the US. The species is subjected to minimal

selection pressure, with reasonably dependable seed production being the primary selection

criterion. As a result, it retains more genetic diversity than would be the case if it were taken to

cultivar status.

To take advantage of the wider choice now available in plant material, we have also adopted

what we call “sculptured seeding” with a number of mixes going on different range sites in the

same field to produce a better adapted, more sustainable planting.

Going back to the question “Seed production of what species?”, I believe the initiation of

alternative native species certification systems in Canada and the US, coupled with the

development and adoption of new planting techniques, will make it increasingly possible for more

people to successfully make more diverse, more ecologically-appropriate plantings. As that

happens, the need for commercially available supplies of a greater range of species will continue

to grow at an accelerated rate. The seed for some of those species will likely continue to come

from native harvest, probably with associated seed increase activity in some cases, some from

traditional cultivar development and production and some from new approaches like Source

Identified and ecovarTM production.

The final question, “How much?”, can only be answered by individual seed producers, based on

the best market analysis information they can get. Native seed prices have historically been

subject to periodic fluctuations and that’s unlikely to change in the future. In spite of those

periodic ups and downs, my personal bet is that the native seed business will be a good place to

be for some time to come.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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ECOVARTM PROGRAM SPECIES

October 1999

Species Area of Origin

Grasses

Awned wheatgrass (A) southern Alberta & Saskatchewan

Awned wheatgrass (B) northern Alberta & Saskatchewan

Big bluestem Manitoba & SE Saskatchewan

Blue grama Manitoba

Fringed brome parkland Alberta, Saskatchewan & Manitoba

Green needlegrass (A) Alberta

Green needlegrass (B) Manitoba

Indian ricegrass Alberta

June grass (A) northern Alberta & Saskatchewan

June grass (B) Manitoba

Little bluestem (A) Alberta

Little bluestem (B) Manitoba

Needle and thread Prairie Canada

Nodding brome parkland Alberta, Saskatchewan & Manitoba

Northern wheatgrass Prairie Canada

Plains rough fescue (A) Alberta

Plains rough fescue (B) Saskatchewan

Porcupine grass Prairie Canada

Prairie cordgrass Manitoba, North Dakota & SE Saskatchewan

Prairie sandreed North Dakota & Montana

Richardson’s brome parkland Alberta, Saskatchewan & Manitoba

Sideoats grama North Dakota

Western wheatgrass Prairie Canada, Montana & North Dakota

Whitetop Manitoba & North Dakota

Forbs

American hedysarum Alberta & Saskatchewan

Canada goldenrod northern Alberta & Saskatchewan

Canada milkvetch Prairie Canada

Cream colored vetch Prairie Canada

Maximilian sunflower Manitoba

Purple prairie clover Prairie Canada

White prairie clover Manitoba

Wild peavine Prairie Canada

Yarrow northern Alberta & Saskatchewan

Shrubs

Western snowberry Prairie Canada

Woods rose Prairie Canada

Winterfat (half shrub) southern Saskatchewan
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Native Grass Establishment: Pitfalls and Potentials

Michael Panciera1

Switchgrass [Panicum virgatum L.], Indiangrass [Sorghastrum nutans (L.) Nash], and big

bluestem [Andropogon gerardii Vitman] are native grasses that are widely adapted in the U.S.

They were once dominant species as part of the tall grass prairie ecosystem, but two agricultural

techniques, tillage and heavy grazing, led to the decline of these grasses. Their broad climatic

adaptation and tolerances to many edaphic and biotic factors have been documented (Duke

1978). These characteristics have helped to rekindle interest in these native grasses for wildlife

habitat, increasing species diversity, soil and water conservation, landscaping, biofuels, and

forage production. Despite the many advantages of these grasses, difficult establishment has

limited their use. The purposes of this paper are to review what is known about establishment,

identify some gaps in knowledge, and offer some challenges for the future.

As a general rule, plants are considered established when they become a stable component of

the plant community. The definition is simple, but the different end uses of these grasses make it

difficult to develop a single set of recommendations for establishment. In an agricultural context,

establishment is often synonymous with dominance. The desired population or density of grass

differs if the purpose of a planting is wildlife habitat. Density must be high enough to provide

shelter, but sparse enough to allow animals to effectively navigate through the stand and search

for food within it. Clearly the criteria for establishment would differ in these two cases, but

planting rates, companion species, and other management variables would likely vary as well.

The wide adaptation and former prevalence of these grasses lead to the assumption that they

should be easy to establish. While some grasses are ubiquitous in their native ranges, such is

not the case for switchgrass, big bluestem, and Indiangrass. The difficulty in establishment is

reflected in the relative lack of agreement for establishment recommendations among several

states (Table 1). The establishment guidelines for these six states are consistent on several

important points. They each indicate that these grasses can be planted with conventional or notill

methods, but weed control must be good and no nitrogen should be applied. In addition,

establishment will normally take two years. The recommendations differ on two key points: the

potential for dormant seeds and ideal planting date. The differences with respect to dormancy

and planting date are difficult to reconcile based on current knowledge of these grasses. There

are some differences in recommendations from state to state for corn or alfalfa establishment, but

the differences can be explained based on environmental differences and the known responses

of corn or alfalfa to environmental factors. More information is needed to develop a similar level

of understanding for the native warm season grasses.

Switchgrass, Indiangrass, and big bluestem have not been subjected to selection pressure for as

long as most introduced grasses. Some traits that are important for survival in the wild interfere

with the speed or uniformity of establishment under cultivated conditions (Leopold 1996). These

traits are regarded as impediments to establishment and they may function at various stages of

development and different processes may be involved (Table 2). Three approaches are possible

to deal with an impediment: remove it (breed them out of the species); overcome it (e.g. seed

treatment for dormancy); or adjust for it (modify management to mimic nature).

Seed dormancy

Seed dormancy is a fundamental problem in establishment because this one factor can

completely negate the best fertility, moisture, and weed control conditions. Seed dormancy is a

condition where either anatomical or physiological characteristics prevent germination (Wareing

1982). Leopold (1996) identified several roles for seed dormancy including: synchronization of

germination and seedling development with good growing conditions; spreading out the time

(year, season) for germination; link germination to ephemeral opportunities; and aiding in the

dispersal of seeds through animals. These functions of dormancy would be valuable in stands

 

1 Dept. of Agriculture and Natural Resources, Berea College, Berea, KY 40404
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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that were being managed for wildlife habitat or conservation. While removal of this impediment

through plant breeding may be an advantage for cultivated crops, it may not be the best solution

for all end uses.

Table 1. Summary of selected recommendations for warm season grass establishment from six

states.

State 2 years for Planting Date

establishment

No N

applied

Till/

Notill

Weed

control

Seed

dormancy Early Late

NE X X X X X

MO X X X X X X

OH X X X X X

KY X X X X X

PA X X X X X X

VA X X X X X

Adapted from: Anderson 1989; Bartholomew et al. 1995; Hall 1994, 1999; Henning 1993;

Rasnake et al. 1998; Wolf and Fiske 1996.

Table 2. Potential solutions for characteristics that impede the establishment of crops.

Process Impediment Solution

Imbibition hard seeds, dry soil scarification, water

Germination slow germ, dormancy genetic selection

’change’ temperature

seed size

seed treatment

modify storage conditions

Seedling Development slow growth

insufficient: water,

nutrients, light

genetics selection

’change’ temperature

weather, weed control

fertility

Dormancy is not as clearly understood as some other plant traits because dormancy develops as

a particular species evolves within an ecosystem. As a result it is difficult to generalize about

dormancy (Chapman 1996; Leopold 1996). For some grass species it is known that temperature

conditions during seedfill, oxygen conditions around the germinating seed, and the location of

seed production can promote the development of dormancy (Chapman 1996). Many factors have

been studied in an effort to define ways to release or reduce dormancy. Light during germination,

chilling imbibed seeds, seed age, seed storage conditions, and acid, mechanical scarification,

bleach, hydrogen peroxide, and gibberellic acid treatments have all been linked to dormancy

release (Chapman 1996; Emal and Conard 1973; Geng and Barnett 1969; Haynes et al. 1997;

Jensen and Boe 1991; Panciera 1982; Panciera et al. 1987; Sautter 1962; Shaidaee et al. 1969;

Tischler et al. 1994; Zarnstoff et al. 1994). One thing is certain, the development and expression

of dormancy cannot be generalized for grass species.

Official procedures for all three grasses discussed here specify that for fresh or dormant seeds a

two week prechill must be used (AOSA 1998). The prechill treatment consists of holding moist

seeds at a temperature of 4°C for 14 days. The official procedures do not require that the
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

16

percentage dormancy be reported. Germination percentage routinely includes dormant seeds

that have been stimulated to germinate by the prechill treatment. The impact of this method of

reporting is that two seedlots with different dormancy may have the same germination percentage

listed on the seed tag. These grasses are planted on a pure live seed (PLS) basis, but PLS may

not accurately define a dormant seedlot. Planting rates based on kg ha-1 of germinable seed

would be more useful. For a dormant seedlot, a single rate of PLS would result in different

germinable seeding rates depending on soil temperatures following planting.

For example, four acres of Cave-in-rock switchgrass were planted on the Berea College farms in

late May 1999. Small plots of Blackwell, Carthage, Shawnee, and Shelter were also planted.

Foxtail and other warm season weeds developed rapidly and switchgrass seedlings were not

numerous. A planting rate of 8 kg PLS ha-1 was used, which should have been adequate for a

good stand. The stand densities in the pasture and the small plots were disappointing.

Subsequent germination tests indicated that all seedlots except Carthage exhibited a statistically

significant amount of dormancy (Figure 1). Soil temperatures did not fall below 15°C after

planting, so temperatures were not sufficiently low to break dormancy. The combination of high

soil temperatures and high seedlot dormancy resulted in a germinable planting rate of about 1 kg

ha-1. Many of the dormant seeds may germinate in the spring of 2000, which will contribute to a

2-year establishment period.

Figure 1. Effect of prechill treatment on the germination of Blackwell (blk), Carthage (car), Cavein-rock (cir), Shawnee (sha), and Shelter (she) switchgrass (Panciera, unpublished data).

0

10

20

30

40

50

60

70

80

90

blk car cir sha she

Cultivar

Germination %

no prechill

prechill
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Figure 2. Effect of seed age and duration of prechill on Indiangrass seed germination

(adapted from Emal and Conard 1973).

Methods of breaking dormancy have been studied for many years. Some authors have reported

that a combination of time and storage conditions can be used to overcome the dormancy

problem (Emal, and Conard 1973; Shaidaee et al. 1969; Zarnstoff et al. 1994). Emal and Conard

(1973) reported that prechilling had less effect on germination as seeds aged (Figure 2). In

addition,

Figure 3. Influence of prechill and seedlot on the germination of one- and two-year old KY

1625 switchgrass seeds (all pairs are significantly different except Exp 1 Big Flats; 1-year old

(Exp 1) and 2-year old (Exp 2) seeds not statistically compared; adapted from Panciera 1982).

the more seeds aged, the less prechill time was required to break the remaining dormancy.

Zarnstoff et al. (1994) found that after 90 days of aging at 23°C, short-term dormancy was

effectively eliminated.

0

20

40

60

80

100

120

1 4 7 10 13

Seed Age (mo)

Germination (%)

No prechill

2 wk prechill

4 wk prechill

0

10

20

30

40

50

60

70

80

90

Big Flats Cape May Quicksand

Location of Seed Production

Germination (%) -

Exp 1 -Control

Exp 1 -Prechill

Exp 2 -Control

Exp 2 -Prechill
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Figure 4. Effect of prechill, bleach, and freezing treatments on germination of three

seedlots of KY 1625 switchgrass (adapted from Panciera et al. 1987).

In studies conducted at Penn State by Panciera (1982), average germination increased as seeds

aged (1 to 2 yr), but seeds continued to respond to prechill treatments (Figure 3). Seeds were

stored at low temperatures (4°C) which may explain the maintenance of dormancy over an

extended period of storage. In addition to prechill treatments, the following methods have also

proven effective for overcoming dormancy in switchgrass and Indiangrass: bleach, acid, hydrogen

peroxide, and mechanical scarification (Emal and Conard 1973; Geng and Barnett 1969; Haynes

et al. 1997; Panciera 1982; Panciera et al. 1987; Tischler et al. 1994). However, it is not clear

that all of these treatments act upon the same impediment to germination. Panciera et al. (1987)

found that prechill and bleach treatments both increased germination of dormant switchgrass

seedlots, but the seedlots responded differently to these two treatments (Figure 4). Germination

for the Cape May seedlot was greatest for the prechill treatment, while the bleach treatment

produced the highest germination for the Quicksand seedlot. Haynes et al. (1997) reported that

prechill, scarification, and bleach all increased switchgrass germination and emergence.

Furthermore, the effects of these three treatments were additive for percent emergence

suggesting that different mechanisms were involved (Figure 5). Under cool conditions, prechill

did not improve emergence, but it did under warm conditions.

Management

Other management inputs that are also important for establishment of these warm season

grasses include planting date, weed control, and nitrogen fertilization. Planting date responses

may involve both dormancy and weed pressure. The lasting effect of planting date on yield

provides an incentive for selecting the best date (Table 3), but conflicting data make the planting

date selection less than clear.

Seedlings invariably develop more rapidly at higher temperatures, thus one would expect that

later planting dates would result in better establishment for nondormant seedlots.

Recommendations for Kentucky and Virginia both cite rapid seedling development as a reason to

plant later (Rasnake et al. 1998; Wolf and Fiske 1996), Pennsylvania recommendations advocate

early planting, in part, to break dormancy (Hall 1994; 1999).

Weed competition for light, water, and nutrients is an important variable in establishment of these

grasses. Since seedling development is slow, weed competition can further slow plant

development. Weed pressure varies by location, season, and year, so planting date may have an

influence on weed pressure. Early planting is cited as a way to reduce weed competition in

Pennsylvania (Hall 1999), while late planting is preferred (for the same reason) in Virginia (Wolf

and Fiske 1996).

0

10

20

30

40

50

60

70

80

90

Big Flats Cape May Quicksand

Location of Seed Production

Germination (%) -

Control

Prechill

Bleach

Frozen
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Figure 5. Effects of temperature and seed treatments on emergence of switchgrass (adapted

from Haynes et al. 1997).

Table 3. Influence of planting date on yield of two switchgrass cultivars.

Year/Cultivar Planting Date1

1 2 34

Seeding year Kg ha-1

Blackwell 810 b2 1279 a 605 b 24 c

KY 1625 404 a 100 b 65 b 1 c

Year after seeding

Blackwell 3694 b 5690 a 3827b 379 c

KY 1625 2185 a 771 b 824 b 27 c

1

Dates: 1 Early May, 2 Late May, 3 Early June, 4 Late June

2

Means within a row followed by the same letter are not significantly different at the 5% level

according to Duncan’s New Multiple Range Test.

Adapted from Panciera and Jung 1984.

Extension Service recommendations presented earlier (Table 1) are in agreement about nitrogen

fertilization. The slow seedling growth of these grasses together with an apparently poor capacity

to respond to N indicate that the addition of this element will favor weeds more than the seeded

grasses. The effect may be more pronounced for some cultivars.

Other factors

The tolerance of seedlings to clipping could be an important avenue for crop improvement.

Because weed control options for these grasses are limited, the ability to recommend mowing as

a weed control technique could improve seeding year management. Preliminary trials in

Pennsylvania indicate that some cultivar differences exist for tolerance to clipping (Dr. G.A. Jung,

personal communication 1999). Further study concerning the variability and heritability of this

trait is warranted.

0

10

20

30

40

50

60

70

None Scarified Scar +

Prechill

Scar +

Pre +

Bleach

Seed Treatment

Emergence (%)

Cool

Warm
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Application of carbofuran (2,3-Dihydro-2,2-dimethyl-7- benzofuranylmethy carbamate) has been

associated with rapid establishment in some cases. While the mechanism has not been

conclusively defined, researchers at Virginia Tech have proposed that carbofuran controls flea

beetle (See Parrish et al. in these Proceedings). Carbofuran is not labeled for use on native

warm season grasses, but an understanding of the mechanisms involved will aid in the

improvement of establishment techniques.

Success on a large scale

Different groups have had excellent success with establishment of warm season grasses. Mr.

Jose Taracido with California University of Pennsylvania and Partners for Fish and Wildlife

Habitat received national recognition for his work using native warm season grasses to improve

wildlife habitat in the 11,000 ha Pike Run watershed in southwestern Pennsylvania (USFWS

1999). He has considerable practical experience with these grasses because he is either a

consultant or primarily responsible for approximately 400 ha of new seedings per year. The

following points summarize some recent conversations with Jose Taracido (Mr. J. Taracido,

personal communication 1999).

Figure 6. An excellent stand of Blackwell switchgrass three months after planting.

• Establishment can be rapid (Figure 6) – up to 1.5 m tall in the seeding year. Conditions

must be perfect for this to occur, but it is possible.

• Success rate is about 95% - The key is how long it will take. Most stands will be in good

condition within two years if producers are willing to apply management

recommendations. Stands still develop without good management, but 3-5 years will be

required.

• The combination of slow seedling growth and dormancy contribute to the two-year time

frame for establishment. Stand density often improves after the first winter, likely due to

germination of dormant seeds. While the majority of seedings are made between April 1

and June 1, planting has been successful even into late autumn. Earlier plantings are

preferred in Pennsylvania, but the later seedings were also successful if herbicides were

used to control competition.

• One of the most beneficial practices is mowing to control weeds. Mowing in the spring of

the year following establishment is an effective method to enhance stand development.

• Be patient.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Criticisms

Several problems exist that make establishment more difficult or, at least, less consistent. First,

too many burdens (time, money, and information) have been placed on the producer. Second,

germination test procedures should indicate the percent dormancy. Obtaining a second

germination test on a seedlot would cost an additional $20 which would only add a few cents per

pound to seed cost. Third, few cultivars have been developed specifically for improved

establishment (Alderson and Sharp 1994). And, fourth, successes have not been carefully

analyzed to explain rapid establishment.

Most forage and conservation crops that are widely used do not put this amount of burden on the

producer:

• Buy expensive seeds.

• Buy seeds a year early.

• Do your own germination test.

• Early or late planting may be best

• Prechill your seeds before planting.

• Within two years, more often than not you will have a good stand.

Most of these recommendations work, but they rely too heavily on the producer. The dormancy

status should be available so producers understand the options (e.g. plant early vs. prechill

treatment). This information is essential because, in most cases, these grasses are being

planted on a small portion of the farm. Livestock producers have limited time and resources

available for long term projects. They simply cannot afford to divert labor and finances away from

the backbone of their feed production system, be it corn silage, cool season pasture, or hay

crops. Despite the need for midsummer pasture, producers will work at it slowly, a few acres at a

time. They could be more aggressive if the results were more certain. The easier it is for the

producer to “do it right”, the higher the probability for success. Consistent results are in

everyone’s best interest because more hectares of these grasses will be planted, so producers

will have more summer pasture, seed dealers will do more business, wildlife habitat will improve,

etc.

Figure 7. Influence of constant ( YVDOWHUQDWLQJ2H[SRVXUHWRSUHFKLOOWHPSHUDWXUHVRQ

switchgrass germination (adapted from Sautter 1962).

Hours at 3-4°C

0 200 400 600 800 1000 1200 1400

Germination (%)

0

20

40

60

80
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

22

Challenges

Consistent results will demand: better cultivars with more aggressive seedlings; better information

including percent dormancy of each seedlot and a systematic explanation of successes;

elimination or circumvention of impediments to establishment; and uniform recommendations.

Several areas of research may provide information that will improve the consistency of

recommendations.

Emal and Conard (1973) found that longer prechill periods were needed to break dormancy in

fresh Indiangrass seeds (Figure 2). Sautter (1962) used different prechill treatments on

switchgrass seeds (Figure 7). These treatments included constant prechill for 14 to 54 d and

prechill only at night for 49 d. The germination data were plotted against hours of exposure to

prechilling temperatures in Figure 7 (assumes a 12 h night cycle). The night only treatment falls

right on the line suggesting that chilling requirements (analogous to growing degree-days) or a

chilling threshold could be defined for dormancy release.

Work by Hsu et al. (1984) suggests that some dormancy is released at temperatures above 4°C

(Table 4). Optimal temperatures appear to change depending on the prechill treatments. When

seeds were exposed to prechilling conditions, optimum temperatures were 20-30°C, but without

the prechill they were lower, in the 15-20°C range. The data are from two separate experiments,

thus not directly comparable, but further study is warranted because such information could lead

to a better definition of optimum planting dates.

No review of this type can provide all of the answers. Impediments to establishment such as

seed dormancy must be identified and addressed in a manner that is consistent with the intended

use for the crop. New ways to improve establishment must be sought through plant breeding and

management with the objective of making consistent results ever easier to achieve.

Table 4. Selected data from two experiments illustrating the influence of temperature on

germination. (Adapted from Hsu et al. 1985.)

Temperature °C

15 20 30

PreChilled % germination

Big Bluestem 37b 47a 34b

Indiangrass 78b 80ab 83ab

Switchgrass (Blackwell) 19c 28b 36a

Switchgrass (Cave-in-rock) 10d 18c 79a

PreChilled % germination

Big Bluestem 38a 32bc 15d

Indiangrass 74a 54b 27d

Switchgrass (Blackwell) 20a 6c 11b

Switchgrass (Cave-in-rock) 11bc 15ab 9cd
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

23

References

Alderson, J. and W.C. Sharp. 1994. Grass varieties in the United States. CRC Press, Boca

Raton, FL.

Anderson, B. 1989. Establishing dryland forage grasses. Nebraska Coop. Ext. Pub. No.G81-

543-A.

Association of Official Seed Analysts. 1998. Rules for testing seeds. AOSA, Lincoln, NE.

Bartholomew, H.M., R.M. Sulc, R. Hendershot, and J. Cline. 1995. Perennial warm season

grasses for Ohio. Ohio Coop. Ext. Pub. No. AGF-022.

Chapman, G. P. 1996. The biology of grasses. CAB International, New York, NY.

Duke, J.A. 1978. The quest for tolerant germplasm, ch. 1 in G.A. Jung (ed.) Crop tolerance to

suboptimal land conditions. ASA Spec. Pub. No. 32, American Society of Agronomy, Madison,

WI.

Emal, J.G. and E.C. Conard. 1973. Seed dormancy and germination in Indiangrass as affected

by light, chilling, and certain chemical treatments. Agron. J. 65:383-385.

Geng, S. and F.L. Barnett. 1969. Effects of various dormancy-reducing treatments on seed

germination and establishment of Indiangrass, Sorghastrum nutans (L.) Nash. Crop Sci. 9:800-

803.

Hall, M.H. 1999. Forages, ch. 8 in N. Serotkin and S. Tibbetts (eds.), Penn State Agronomy

Guide. Pub. No. AGRS-26, College of Agricultural Sciences, Pennsylvania State Univ.,

University Park, PA 16802. Available online: http://AgGuide.agronomy.psu.edu/ Access date 5

Aug 99.

Hall, M.H. 1994. Warm season grasses. Agronomy Facts No. 29. Pennsylvania State Univ.

Coop. Ext., University Park, PA 16802.

Haynes, J.G., W.G. Pill, and T.A. Evans. 1997. Seed treatments improve the germination and

seedling emergence of switchgrass (Panicum virgatum L.). HortSci. 32:1222-1226.

Henning, J. 1993. Big bluestem, Indiangrass, and switchgrass. Missouri Coop. Ext. Pub. No.

G04673. Available online: Access date 5 Aug 99.

Hsu, F.H., C.J. Nelson, and A.G. Matches. 1985. Temperature effects on germination of

perennial warm season grasses. Crop Sci. 25:215-220.

Jensen, N.K. and A. Boe. 1991. Germination of mechanically scarified neoteric switchgrass

seed. J. Range Mgt. 44:299-301.

Leopold, C.A. 1996. Natural history of seed dormancy, pp. 3-16 in, G.A. Lang, ed. Plant

dormancy: physiology, biochemistry, and molecular biology. CAB International, New York, NY.

Panciera, M.T. 1982. Germination, seedling growth, and establishment of switchgrass as

affected by several environmental, physiological, and management factors. Ph.D. diss.

Pennsylvania State Univ., Univ. Park, PA (Diss. Abstr. 83-05681).

Panciera, M.T. and G.A. Jung. 1984. Switchgrass establishment by conservation tillage: planting

date responses of two varieties. J. Soil Water Conserv. 39:68-70.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

24

Panciera, M.T., G.A. Jung, and W.C. Sharp. 1987. Switchgrass seedling growth and cultivar

dormancy: potential effects on establishment. Proc. Am. Forage Grassland Council, 2-5 Mar

1987, Springfield, IL.

Rasnake, M., J. Henning, and D. Stipes. 1998. Warm season perennial grasses for forage in

Kentucky. Kentucky Coop. Ext. Pub. No. AGR-145.

Sautter, E.H. 1962. Germination of switchgrass. J. Range Mgt. 15:108-110.

Shaidaee, G., B.E. Dahl, and R.M. Hansen. 1969. Germination and emergence of different age

seeds of six grasses. J. Range Mgt. 22:240-243.

Tischler, C.R., B.A. Young, and M.A. Sanderson. 1994. Techniques for reducing seed dormancy

in switchgrass. Seed Sci. Tech. 22:19-26.

U.S. Fish and Wildlife Service. 1999. Farmland habitat project gains Mellon Foundation grant via

Pike Run project. Available online: http://partners.fws.gov/AWARDS/pikerun.html Access date

30 Oct 1999.

Wareing, P.F. 1982. Hormonal regulation of seed dormancy – past, present, and future, pp. 185-

202 in, A.A. Khan, ed. The physiology and biochemistry of seed development, dormancy, and

germination. Elsevier Biomedical Press, Amsterdam, Netherlands.

Wolf, D.D. and D.A. Fiske. 1996. Planting and managing switchgrass for forage, wildlife, and

conservation. Virginia Coop. Ext. Pub. No.418-013.

Zarnstoff, M.E., R.D. Keys, and D.S. Chamblee. 1994. Growth regulator and seed storage

effects on switchgrass germination. Agron. J. 86:667-672.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

25

Native Grass Management

Dan Carroll and Floyd Knowlton1

Abstract

The Oak Orchard and Tonawanda Wildlife Management Areas are located in the Western New

York Lake Plains region approximately half way between Rochester and Buffalo. These areas

are managed to provide emergent marsh and grassland habitat for a variety of wildlife including

endangered, threatened and special concern species. The grassland objective is to develop and

maintain approximately 500 acres of dense nesting cover of which 50 percent is native warm

season grass and 50 percent is introduced cool season grass. The warm season grass is

primarily switchgrass established on the higher, more droughty soils (Elnora sand). This poor-soil

grass will provide excellent nesting cover for wildlife without annual additions of lime and fertilizer.

Switchgrass is maintained on these areas by controlled burns and mowing. In recent years over

100 acres of switchgrass seed production has been harvested from the Management Areas to

provide for additional plantings throughout the New York State Wildlife Management Area

system. Cool season grasses are established on the lower, wetter soils by planting or through

natural invasion onto tilled, compacted seedbeds. The cool season grasses are managed for

later-nesting birds. Suitable nesting cover is created by mid to late spring grass growth. All of the

cool season grasses are maintained by an annual August mowing. Other management activities

associated with grasslands include hedgerow removal and shoreline clearing. The removal of

these woody plants increases the size of grasslands, controls invasive woody plants, reduces

predation, and increases the utilization by and nesting success of the grassland species of

wildlife.

 

1

 Wildlife Biologist and Senior Fish and Wildlife Technician, New York State Department of

Environmental Conservation
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

26

Non-native Genotypes and Outbreeding Depression in Plants: Theoretical

and Empirical Issues

Christopher T. Frye1

The increasing use of locally non-native seed stock of many species in agricultural and wildlife

management programs have raised several issues regarding the ecological/genetic effects that

such programs may have upon natural populations of these same species. There is therefore a

need to investigate the ecological implications of using so-called non-native genotypes (NNG’s)

for outplanting in areas where there is a high probability that introgression (via pollen and seed)

will occur between outplanted and native populations of these species. The supposed

deleterious effects of such introgression are called outbreeding depression (OBD) (sensu Shields

1982, Templeton 1986). The major goal of this paper is to examine, through reviewing the

scientific literature, the theoretical mechanisms of OBD and the empirical studies of plants

concluding evidence of OBD. Other goals are to identify OBD in the contexts of fields of

biological inquiry; to identify sources of information, and to promote discussion among biologists

regarding the evolutionary and ecological implications of outplanting NNG’s.

Outbreeding depression (OBD) is defined as the reduction in fitness (of the progeny)

accompanying the crossing of genetically dissimilar individuals. Some of the potential affects of

using NNG’s are: 1) loss of genetic diversity by swamping of native genotypes, 2) reduction of

population sizes through the introduction of deleterious or lethal alleles, 3) loss of evolutionary

potentials through genetic homogenization, 4) unforeseen changes in plant-animal interactions,

and 5) loss of research potential utilizing native populations. This paper will not so much argue

whether or not the above actually occur but will take issue with the broad application of such

ideas because they are based on premises that may be too general and simplistic for such a

complex biological phenomenon.

Reports of OBD in plants has created much concern among conservation biologists whom often

explicate the phenomena using terms such as genetic assimilation, genetic pollution, or genetic

swamping, but often these terms are used vaguely and with few or exceptional examples ignoring

more common issues (Lynch 1996, Millar and Libby 1989). Without the specific contexts for

using these terms, such as offered by Ellenstrand (1992), this has, in the author’s opinion, tended

to create much confusion. Additionally, the literature regarding both inbreeding and OBD has

been consistently plagued by semantic problems arising from different paradigms and

conceptions of what outbreeding and inbreeding mean, and how they are defined (Shields 1993).

Thus, it is imperative that in this discussion a clear context be formed for what follows.

Firstly, most of the literature regarding OBD that promotes the use of extreme caution in

population augmentation or outplanting programs focuses squarely on rare and/or narrowly

endemic species (Falk and Holsinger 1991, Ellenstrand 1992, Ellenstrand and Elam 1993, Falk et

al. 1996, Avise 1994, Lynch 1996). The discussion here will not focus on rare species per se but

rather on the basic biological mechanisms underlying OBD. Secondly, it should be understood

that there are many levels of genetic dissimilarity. There exists a continuum of levels of genetic

dissimilarity from matings between congeners (interspecific hybrids) to matings between local

populations at various distances. This paper takes a different approach to the study of OBD by

ignoring arguments as to whether or not OBD actually occurs in nature or can be deleterious

since at some level of genetic dissimilarity outbreeding produces OBD (e.g., sterile hybrids).

This paper reflects the opinion that OBD can be expressed within the context of evolutionary

biology as a continuum from mild reductions in fitness to F1 inviability; thus OBD may be seen as

a consequence of natural selection capable of producing divergent lineages if selection is

 

1

 Maryland Department of Natural Resources, Wildlife and Heritage Division, 580 Taylor Avenue,

Annapolis, Maryland 21401
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

27

sufficiently strong. Additionally, other factors as diverse as historical phylogeography, taxonomic

concepts and mating system evolution, either working in concert with selection or alone may have

a profound influence on the expression, severity and persistence of OBD in plants. Identifying the

contexts of history, taxonomy, and genetics and the mechanisms of OBD will form the bulk of this

review.

Firstly, I will discuss OBD in a historical context. This discussion will examine how past history,

both natural and anthropogenic, may affect plant distribution and genetic structuring across a

taxons range which would in large part determine the propensity for OBD. Throughout this paper

propensities rather than outcomes or probabilities are discussed because evolutionary outcomes

may often have very long time-frames and while we may discover trends we cannot be sure that

these trends may not be altered by future events (see Mills and Beatty 1994 for discussion).

Secondly, I will discuss OBD in an evolutionary-taxonomic context. While at first this may seem

peripheral it is extremely important that clear taxonomic concepts be applied since even our

conceptualization of species as entities is temporal. Schierup and Christiansen (1996)

conceptualize OBD as the “population counterpart to mechanisms separating species or

subspecies”. This all too rare, but very clear statement indicates that populations may diverge,

speciate and that these species may have distinct subdivisions and so on. However, the difficulty

arises where these boundaries become difficult to distinguish (such as in many intraspecific taxa).

It is very important that taxonomic categories be clearly defined (through consulting the

taxonomic literature) to prevent conflating taxonomic categories with evidence for pervasive OBD

in plants.

Thirdly, I will discuss OBD within an ecological-genetic context. This will include the examination

of life history components of plant species but particularly the breeding system and how this may

affect the propensity for OBD in plants. An analysis of empirical studies published within the last

two decades will be presented in this section.

Although discussed primarily in the final section of this paper there is a need to introduce three

important questions that have been largely ignored but are singularly important for conservation

biologists and land managers evaluating a taxon for outplanting:

1) Is OBD predictable for taxa that have a certain suite of characteristics?

2) Is the resulting OBD likely to be severe?

3) Is the resulting OBD likely to persist?

Mechanisms of Outbreeding Depression

The genetic mechanisms underlying the expression of OBD in plants have received some

theoretical work but very little empirical confirmation. Outbreeding depression in plants is poorly

studied and perhaps only became of interest to evolutionary biologists after Price and Waser

(1979) reported the finding of an optimal outcrossing distance in the plant Delphinium nuttalianum

Pritz. (Delphinium nelsonii Greene of cited studies herein). This is significant because in order for

there to be an optimal outcrossing distance there must be selective pressures attempting to

produce an equilibrium between inbreeding (which has the advantage of conferring a maternal

advantage if the parental plants are well adapted) and outbreeding which has the advantage of

conferring heterosis or new, potentially better adapted genes to their offspring (see Shields 1982).

An optimal outcrossing distance also indicates that there is an optimal genetic relatedness

between mates and since in plants genetic similarity is usually a function of distance between

individuals or populations this raised (I believe) the spectra that perhaps increasing the genetic

variation of a population is not necessarily always desirable.
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28

While the specific genetic causes of OBD are not well understood there are two types of

theoretical mechanisms that are reported in the literature. The first mechanism thought to be

responsible for the perceived OBD is that resulting from local adaptation of the genome to the

environment. This is the ecological or extrinsic mechanism (Price and Waser 1979, Shields

1982, Fischer and Matthies 1997, Waser and Price 1993, Ellenstrand and Elam 1993) and is the

more intuitive of the two theories. Under this mechanism populations are over evolutionary time

expected to become adapted to their local environmental conditions through a combination of

restricted gene flow between sites, local selection and genetic drift. Evidence for local adaptation

in plants is strong and adaptive divergence has been documented on very small scales (reviews

by Linhart and Grant 1996, Waser 1993). If selection favors the increasing coadaptation of the

genome to the environment then the importation of NNG’s is expected to breakup the coadapted

gene complexes (via recombination) responsible for local adaptation (Lynch 1996). The evidence

is not necessarily straightforward as the expression of heterosis or hybrid vigor is common in the

F1 generation (Shields 1982, Thornhill 1993) and there is some disagreement about the relative

severity of OBD in plant populations ( see Templeton 1986 and Lynch 1996). Lynch (1996)

suggests that the negative consequences of outbreeding may take several generations for full

expression, as heterotic effects begin to breakdown with subsequent backcrossing in later

generations, but it appears that this assumption was made with certain conditions in mind (e.g.

weak selection, fast generation time, etc.). One obvious confounding factor is the time scale over

which this may occur. For example the severity of OBD should vary widely among different life

forms (e.g., annuals versus long-lived perennials) as the time to produce a new cohort would vary

greatly. Additionally, there is a problem of the scale of gene flow via pollen. One would have to

assume that the rearrangement of the genome via interpopulational gene flow and selection is a

fairly frequent occurrence in nature; at least in continuous populations. What is at issue here is, a

potentially large-scale, human mediated gene flow that may alter the time frames considerably.

The second mechanism hypothesizes that local gene pools can be coadapted intrinsically

(Templeton 1986, Lynch 1991, 1996) that is, even if the external environment is uniform the

internal genetic environment is expected to develop coadapted complexes of genes by epistatic

interactions (Campbell and Waser 1987, Mitton 1993). Empirical studies regarding this

mechanism are few but are fairly robust (Schneller 1996, Parker 1992, Svensson 1990) as are

the theoretical genetic models (Campbell and Waser 1987, Lynch 1991, Schierup and

Christiansen 1996). Under this mechanism NNG’s would break up the favorable gene complexes

(via recombination) that have formed (perhaps solely due to chance) and tend to become

inherited together in the local gene pool.

Given that plants are sedentary and that gene flow by pollen and seed tend to be fairly localized

(Levin and Kerster 1974, see also Ellenstrand 1992) we should expect that any disruption of the

historical patterns of gene flow among populations has the potential to breakup the kinds of

coadaptation that may form among populations. However, it is far from clear that the in situ

fitness of individuals within a given population is necessarily optimal or even likely to be optimal,

since an optimal genotype may only be optimal for a given environment at a given time, i.e., it is

temporal. It is always possible that in some cases further outbreeding or inbreeding may be

beneficial, by moving the population to a higher “adaptive peak”. Thus broadly invoking local

adaptation as a cause of OBD has no particular theoretical rigor because it assumes the

optimality of current conditions that is within the perspective of the observer not the species

lineage.

The Historical Context of Outbreeding Depression

If we conceptualize OBD as resulting from genetic divergence of populations then both historical

patterns of geographic distribution as well historical and recent patterns of gene flow need to be

evaluated. For example, the present range of a species may not reflect its past distribution

(Harper 1977); a once widespread species may have experienced a severe decline in range or

are of relatively recent origin and never occupied a large range (see Karron 1991). Additionally,

historical land use and human mediated changes in plant communities may create
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

29

phylogeographic patterns over the landscape (Motzkin et al. 1996). Discovering these historical

details will probably not be easy thing to do, but some amount of study of historical

phylogeography would lend one measure of confidence in predicting the occurrence of OBD.

Given that plants are non-motile, they become subject to both temporal and spatial selective

pressures. While there has been considerable study of local population dynamics there has been

until relatively recently, little study of how past events have shaped the distribution of both plant

species and their genetic variation. Recent progress (Mahy et al. 1999, Utelli et al. 1999) has

been facilitated by advancements in molecular technologies for interpreting phylogeographic

patterns of population-genetic structure (see also Hedrick 1999).

Why would past events that occurred hundreds or even thousands of years ago be important in

understanding OBD? Primarily, this has to do with the partitioning of genetic variation of a taxon

within and among populations. The genetic substructuring of species and populations across the

range of the taxon is influenced not only by the breeding system (Hamrick and Godt 1996a) but

also by patterns of gene flow and intensity of selection (Linhart and Grant 1996). All of these

would be modified directly, or indirectly, by past range contractions and expansions.

For example, during the Pleistocene, at the height of the Wisconsin glaciation what we know as

the Delmarva Peninsula would have been a vast grassland mixed with conifers such as red

spruce [Picea rubens Sarg.] (Scott 1989). During this period of time much of our present flora

would have been pushed into glacial refugia in the southern United States. Recent studies show

that such range contractions have had dramatic and long-lasting effects on the genetic structure

of plant populations (see review by Thompson 1999). In red pine [Pinus resinosa Aiton] and

eastern hemlock [Tsuga canadensis (L.) Carriere], no and little genetic variation (respectively) at

isozyme loci has been found despite wide current distributions in the northeastern United States.

This result was surprising, especially for conifers which are typically highly variable (Hamrick and

Godt 1989, Hamrick and Godt 1996b, p. 292). The situation in red spruce is attributed to

Pleistocene glaciation which reduced the species to a small area and the subsequent inbreeding

eliminated variation (Millar and Libby 1991, ch. 10). The notable absence (4800 ybp) of eastern

hemlock from the flora for a period of about 1000 years indicates that the species passed through

a severe bottleneck eliminating (perhaps by disease) most genetic variation (Hamrick and Godt

1996b, p. 282). During the range contractions of the Pleistocene it is likely that the genetic

composition of many species changed dramatically (see Hewitt 1996) and some evidence

suggests that the most diverse populations of northeastern species may be found in those

remnant populations that now exist as isolates in patchy habitats. Such is the case for swamp

pink [Helonias bullata L] where the most genetically diverse populations are located in peripheral

populations in the Southern Appalachians now widely disjunct from the main northeastern range

(Godt et al. 1995, Hamrick and Godt 1996b Pp. 293-294). This finding is intuitively satisfying

given that we would expect some sampling error to occur as the species recolonized the

northeast following glacial retreat and indicates that genetic drift has played a major role in the

genetic structure of this species. Restorationists should be mindful of this study for other

northeastern herbaceous species as it indicates relatively short periods of population isolation.

Additionally, in cases of man-created habitat fragmentation the genetic differences that may arise

between populations may be seen as artificial and perhaps not desirable.

One of the most interesting climatic events in some respects was the pronounced warming period

called the Xerothermic (ca. 3200 ybp) during which some components of midwestern floras

expanded their ranges eastward. This would have likely included several warm season grasses

typical of prairies such as little bluestem [Schizachyrium scoparium (Michx.) Nash], big bluestem

[Andropogon gerardii Vitman] and Indiangrass [Sorghastrum nutans (L.) Nash] which are

currently widely outplanted. Remnant prairies may be found at many sites in Maryland where

edaphic conditions have slowed successional rates. Species typical of western floras may be

found in these environments supporting the hypothesis that these species colonized during the

prolonged drought. Whether the movement of these species took place as a wave of

advancement or as founder populations following long-distance dispersal events is unknown; but
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

30

it is likely that this expansion founded many populations of these plants that we see at the

present.

The distinction between a wave of advancement and long-distance founder events is an

important one. If the species expanded its range as a wave then there are reasons to believe

that genetic divergence would be minimal since in relatively recent time there could have been

considerable gene flow between currently isolated populations. If the species expanded its range

due primarily to long-distance founding of populations then there would be reason to believe that

a combination of genetic drift and small population size from few or single founders would create

conditions conducive for divergence. Nichols and Hewitt (1994) found that in modeling the two

types of range expansion that “if long distance dispersal is sufficiently frequent, the populations

do not spread as a wave of advancement but instead found intermingled isolates.” In a study of

metapopulation dynamics of the weedy plant Silene alba (Mill.) E. H. L. Krause, McCauley et al.

(1995) reported little mixing of individuals in founding of new populations even with the presence

of a diverse source population from which to draw alleles. These results are consistent with

estimates of rapid plant migration and recolonization from glacial refugia (Merrell 1981, p. 412,

Cain et al. 1998). Clearly, the occurrence and severity of OBD in plants may be strongly

conditioned by past events.

If historical factors are capable of producing divergent lineages then the historical context of OBD

demands that the taxa likely to have developed isolating mechanisms be identified. These

isolating mechanisms as traditionally defined by the Biological Species Concept (Mayr 1970) can

be important in predicting the severity of OBD. Some measure of predicting the severity of OBD

may be found within classical morphological taxonomy.

The Evolutionary-Taxonomic Context of Outbreeding Depression

Classic morphological taxonomy has been subject to criticism under the Biological Species

Concept (see Mayr 1994). Often taxonomy is criticized as being wholly typological; which refers

to the inherent equivocality in defining the type and setting limits, i.e., what amount of divergence

from the type is enough to categorize species, subspecies, variety etc. The confusion created by

applying (or lack of applying) different species concepts is apparent in two studies of OBD in

plants. In an often-cited empirical study of OBD in plant populations, Parker (1992) performed

artificial crosses between two populations of a widespread, predominately selfing, annual plant,

the hog peanut [Amphicarpaea bracteata (L.) Fernald]. The populations were found to consist of

fixed sets of alternative alleles at 12 loci and were so identified as “biotypes”. Crosses between

the two populations expressed severe OBD in the form of significantly reduced seed biomass and

other fitness characters. Since the two populations existed in the same general environment it

was concluded that the OBD mechanism could not be attributed to gene-environment

coadaptation but to internal or intrinsic coadaptation between favorably interacting gene

complexes.

The point here is that what has been cited as clear evidence of OBD in widespread plant species

could also be considered to be an entirely predictable reduction of fitness resulting from crossing

two different taxa. The two “biotypes” correspond to two segregate taxa (varieties) described by

Gleason and Cronquist (1991) and Fernald (1950). Evidently the formation of rare hybrids was

taken as evidence against taxonomic delimitation as a consequence of a strict application of the

Biological Species Concept, requiring complete reproductive isolation. In this study historical

factors were discounted but it is apparent that taxonomic concepts can be used to predict the

occurrence if not the severity of OBD. In a similar situation, Walters et al. (1995) in determining

genetically appropriate local stock of the widespread wiregrass [Aristida stricta Michx.] indicate

throughout their paper a deep concern over the potential for OBD in populations of wiregrass due

to inappropriate stock use in restoration projects. Emphasizing different electrophoretic profiles

between populations the authors concluded that collections of wiregrass should include

separately maintained accessions from local populations. This potential for OBD was confirmed

by Peet (1993) in a taxonomic study of the Aristida stricta complex who determined that the
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

31

grasses traditionally assigned to this species included two morphologically and ecologically

distinct species.

In the examples above the taxa were difficult to distinguish morphologically and only careful study

and the use of genetic tools such as enzyme electrophoresis uncovered the underlying

differences. Clearly, taxonomic evidence can be used to at least assign a probability for the

occurrence of OBD. The occurrence of intraspecific taxa within a species indicates that

evolutionary forces, especially selection, have ordered phenotypic and genotypic traits along

environmental or ecological gradients. Interpreting phenotypic patterns is the job of taxonomists

and the various floras are the sources for valuable information. For example, the common and

widespread grass little bluestem [Schizachyrium scoparium (Michx.) Nash] exhibits a wide range

of phenotypes associated with particular regions of the United States and/or distinct habitats

(Fernald 1950). If environmental heterogeneity promotes genetic heterogeneity then this should

be taken as a clear indication that widespread species with high amounts of intraspecific variation

indicate different evolutionary trajectories of these taxa and care should be taken in choosing

appropriate stock for outplanting.

Employing taxonomic evidence should substantially facilitate our assessment of OBD in a given

situation. This premise is well founded as differential phenotypes could well indicate different

selection regimes and the possibility of genetic divergence (Linhart and Grant 1996). Clearly

applying taxonomic concepts will also provide a context for OBD and eliminate confusion that

may occur through conflating taxonomic concepts with evidence for pervasive OBD in plants.

Taxonomists would be quick to add that the weakness of morphological taxonomy is also its

strength, the recognition of phenotypic patterns in nature.

The Ecological-Genetic Context of Outbreeding Depression

Plant populations may often be genetically and phenotypically variable over geographic space

(for historical perspective see Briggs and Walters 1969; Epperson 1990). In fact genetic

subdivision in plant populations may occur over distances of a few meters and genetic divergence

as measured by neutral loci is typical among populations of many species. Spatial genetic

structure is primarily determined by distances of gene flow and migration between populations.

Additionally, life history components of species may have a profound effect on genetic structuring

of populations (Loveless et al. 1998). Indeed, conservation biologists have long recognized that

certain characteristics of rare species increase the probability of extinction via the loss of genetic

diversity through inbreeding effects. These same characteristics have the potential to influence

the evolution of mating systems. For example, selection may favor the evolution of selfing in rare

species due to characteristics such as small population size, poor or unpredictable pollinator

service, and isolation from other populations due to restriction to patchy habitats (Karron 1991).

Additionally, as discussed previously, historical factors that may contribute to isolation may

influence the amount of genetic subdivision and divergence.

What are the consequences of such dramatic subdivision? Does the finding of genetic differences

between populations reflect local adaptation to a site via strong local selection, random genetic

drift, or some combination of the above? Additionally, how do we reconcile the finding of optimal

outcrossing distances of a few meters with substantial evidence for at least F1 heterosis in

crosses between distant populations? While a full exposition on life-history characteristics is

beyond the scope of this paper the literature strongly suggests that the breeding system of plant

species is a useful character in predicting distances of gene flow and determining the degree of

genetic subdivision, and so it would appear that the breeding system of a plant would be similarly

useful for predicting OBD. Implicit in this discussion is that in species where genetic population

subdivision is substantial that this subdivision is created and maintained by selection i.e., they are

not a series of random events but highly repeatable observations for certain breeding systems. If

these assumptions are correct then local adaptation by either the ecological or genetic

mechanism is conditioned by the breeding system.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

32

The manner in which genetic variation is distributed among populations of a species is closely

tied to gene flow (Levin and Kerster 1974, Loveless and Hamrick 1984). Hamrick and Godt

(1989, 1996a) examine the correlation between and number of life-history traits and genetic

variation. One of the strongest correlations occurs between plant mating system and the

distribution of genetic variation among and within populations, with selfing species showing a

significantly greater degree of genetic variation among populations rather than within populations.

Outcrossing species show a typical pattern of more of the genetic variation distributed within

populations rather than among populations. If a selfing mating system leads to greater genetic

subdivision between populations due to low rates of gene flow, then it logically follows that these

species have at least the opportunity for greater divergence given some degree of local selection

or drift. Since OBD is defined as a loss of fitness occurring as a consequence of matings

between genetically dissimilar individuals then we should find a correlation between a selfing

mating system and the expression of severe OBD. Of course any degree of population

divergence within a species would depend heavily on the strength and direction of selection, as

well as historical factors such as past genetic bottlenecks and the period of time over which

isolation has occurred. Thus, it is expected that the correlation between mating system and OBD

will not always be a strong one.

If the expression of OBD is correlated with the mating system of a plant then the data from

experimental crosses over distance and breeding systems should indicate trends. For this

purpose 36 studies (40 taxa) that indicated variation in fitness with crossing distance or between

selfed and outcrossed flowers were reviewed.

Table 1. Associations between mating system and outbreeding depression.

Reference Species Breeding System

Fischer and Matthies 1997 Gentianella germanica (Willd.) Borner

ex E. F. Warb

Selfing

Parker 1992 Amphicarpaea bracteata (L.) Fernald Selfing

Schneller 1996 Asplenium ruta-muraria L. Selfing

Waser and Price 1979,

1994

Delphinium nelsonii Greene Outcrossing selfcompatible

Svensson 1990 Scleranthus annuus L. Selfing

Raimundez and Ramirez

1998

Hypoxis decumbens L. Selfing

Waser and Price 1989 Ipomopsis aggregata (Pursh) V. E.

Grant

Outcrossing selfcompatible

Sobrevilla 1988 Espeletia schultzii Wedd. Outcrossing selfcompatible

Levin 1984 Phlox drummondii Hook. Outcrossing selfincompatible

Schemske and Pautler

1984

Costus allenii Maas Outcrossing selfcompatible

McCall et al. 1991 Impatiens capensis Meerb. Mixed

Schmitt and Gamble 1990 Impatiens capensis Meerb. Selfing*

Twelve studies (11 taxa) concluded evidence of OBD at long crossing distances (Table 1). Of

these 12 studies five species were described as being highly selfing or autogamous, two species

were outcrossing but self compatible, 3 species were outcrossing and self-incompatible and one

specie had a mixed mating system with both cleistogamous and chasmogamous flowers. While

the trend of a selfing breeding mechanism was confirmed, the three studies observing OBD for

outcrossing and self-incompatible species was unexpected. Waser and Price (1989) concluded

that OBD in Ipomopsis aggregata was expressed over lifetime fitness with intermediate (optimal)

outcrossing distances having the greatest fitness. Waser (1993) reports that for this species
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33

(Ipomopsis aggregata) there was a 12% detriment in seed maturation relative to the intermediate

cross and a 32 % detriment in lifetime F1 fitness of the offspring in the field. The presence of

strong self-incompatibility in this species coupled with an apparent small genetic neighborhood

size is counterintuitive. Large neighborhood sizes were found in the self-incompatible Asclepias

exaltata L. (Broyles and Wyatt 1991). In another strongly self incompatible species [Aster

furcatus E.S. Burgess] it became necessary to augment local populations to regain normal seed

set (Les et al. 1991). It is possible that other life history traits aside from breeding system were

responsible for this finding such as animal (hummingbird) pollination or monocarpy.

Sobrevila (1988) described OBD in Espeletia schultzii at crossing distances greater than 500

meters. OBD was expressed as an increase in seed abortion (% filled achenes), a 23%

detriment relative to the intermediate cross (in Waser 1993) but the authors concluded that there

was a strong environmental effect. Populations of E. schultzii presented different phenotypes at

different elevations and it was concluded that populations may be undergoing some divergence

and so one must also apply the evolutionary-taxonomic context to this species.

Levin (1984) reported OBD in the annual, Phlox drummondii as expressed by seed abortion, but

only in half the crosses at 200 meters; the other half showed evidence of heterosis. The review

by Waser (1993) does not indicate OBD for this study and instead indicates that the longest

crosses performed best. All of the species reported by Waser where the longest crosses

performed best are outcrossing and self-incompatible (Waser 1993, Table 9.4), as would be

expected.

The evidence for OBD in those species described as outcrossing but self-compatible is weak or

extremely variable. Only Delphinium nelsonii (Waser and Price 1994) exhibited strong OBD as

expressed over the lifetime of the individual. OBD in Costus allenii (Schemske and Pautler 1984)

was expressed as consistent reductions in seed number per fruit and percent germination,

however two other fitness components showed increases (seed weight and total dry weight). The

only species with a mixed mating system (Impatiens capensis) expressed an optimal outcrossing

distance (and thus OBD) in one trait (seedling height at one month) but the authors (McCall et al.

1991) concluded that the optimum resulted from a negative correlation between interparent

distance and seed weight and that emergence and survival were not correlated with crossing

distance. Other studies with Impatiens capensis (Schmitt and Gamble 1990) found evidence for

OBD only with seed derived from cleistogamous (selfing flowers). Extreme variation among

maternal parents in experimental crosses is frequent (Parker et al. 1995) making the

interpretation of the data difficult. Additionally, maternal effects appear to break down over time

(Wolfe 1993) and perhaps the severity of OBD due to local adaptation would be ameliorated over

generations.

Studies describing inbreeding depression were abundant and include all but two of the studies

(Parker 1992, Schneller 1996) in Table 1; a selfing annual and a homosporous inbreeding fern

respectively. Thirty-three studies covering 39 taxa described significant inbreeding depression for

self or short crosses as compared to outcrossed or long crosses. Tabulating the breeding

systems for these 39 taxa produced trends consistent with lower inbreeding depression for

species with a selfing breeding system and high inbreeding depression for species with an

outcrossing breeding system (Table 2). Only four of the 39 species were described as selfing

(Fischer and Matthies 1997, Svensson 1990, Parker et al. 1995, Carr and Dudash 1996) whereas

nineteen were outcrossing but self compatible (Waser and Price 1994, Dudash 1990, Van

Treuren et al. 1994, Helenurm and Schaal 1996, Lyons 1996, Holtsford 1995, Trame et al. 1995,

Oostermeijer et al. 1995, Schemske and Pautler 1984, Carr and Dudash 1996, Husband and

Gurney 1998, Delesalle and Muenchow 1992, Johnston 1992, Montalvo 1992, Wolfe 1993, Galen

et al. 1985, Coles and Fowler 1976), 12 were outcrossing and self incompatible (Broyles and

Wyatt 1991, Lyons 1996, Waser and Price 1989, Newport 1989, Sobrevila 1988, Levin 1984,

Young and Brown 1998, Harder et al. 1995, Redmond et al. 1989, Koptur 1984) and three were

considered to have a mixed breeding system (Schoen 1983, McCall et al. 1991, Schmitt and

Gamble 1990, Ayre et al. 1994).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

34

Table 2. Frequency of different breeding systems among studies finding inbreeding depression.

Breeding System Frequency (N-39 taxa)

Selfing 0.103

Outcrossing self-compatible 0.487

Outcrossing self-incompatible 0.307

Mixed 0.103

The general trends of these studies support the hypothesis that in situations where gene flow is

localized and subsequently natural inbreeding in the population is occurring that the propensity of

the population to exhibit OBD is increased. Local adaptation may be particularly strong for highly

selfing species for several reasons. Firstly, the whole genome may be tightly linked as a

consequence of increasing relatedness among members of the local population. Secondly,

selfing species should experience a slower decay of linkage disequilibrium (Hamrick et al. 1991)

than outcrossing species given that recombination within a genome that is extremely

homozygous produces little change. Thirdly and related to the above, genetic variation is

typically low within populations of selfing species but may be highly variable among populations.

The latter has two explanations. Either it is the case that populations are formed from few

founders that by chance have generally equal fitness or populations are formed from many

individuals drawn from a source pool and strong selection sorts the progeny into a few fit

genotypes. In either case the indication is that in highly self-fertilizing species local adaptation to

the environment is highly plausible (Pannell and Charlesworth 1999).

Are there reasons to believe that selection is capable of producing such breeding system

plasticity? If selection for self compatibility or selfing among plant species is favored where there

are reduced opportunities for outcrossing then there should be situations where the mating

system shows some plasticity in responding to selection. Such data is present in four studies. In

Leavenworthia crassa Rollins (Lyons 1996) different populations show dramatic differences in

outcrossing rates. Furthermore, these differences in outcrossing rates are associated with

phenotypic divergence. The highly outcrossing populations of L. crassa have strongly scented

flowers and extrorse anthers whereas the selfing populations have smaller, lightly scented flowers

and introrse anthers. Charlesworth and Zang (1998) conclude that selfing in L. crassa may be of

recent evolutionary origin. In Clarkia tembloriensis Vasek (Holtsford and Ellenstrand 1990,

Holtsford 1996) outcrossing rates varied between populations and these were highly correlated

with anther-stigma separation and the degree of protrandry. Additionally, the selfing populations

occupied marginal habitats where there were more severe environmental conditions leading to

drastic population fluctuations. Ayre et al. (1994) report high levels of selfing in the rare

Australian shrub Grevillea barklyana F. Muell. ex Benth. that were unexpected given that most of

the taxa in the family Proteaceae are highly outcrossing and that experimental crosses indicated

a preference for outcross pollen. A fourth population of G. barklyana was found to be highly

outcrossing indicating that the breeding system may vary widely and may be less than optimal.

For highly outcrossing species, high migration rates and longer distances of pollen movement

may be inferred from high genetic diversity at both the population and species levels, especially

for wind-pollinated species (Hamrick et al. 1991, Table 5.1, 5.2, Godt and Hamrick 1998).

Therefore, there is less probability that populations will exhibit OBD due to local adaptation

except in situations where there is strong selection due to extreme environmental conditions (e.g.,

heavy metal tolerance).

The data are sufficient to support the hypothesis that OBD in plants can be predicted with some

reasonable assumptions if appropriate attention is given to understand the generalities of the

mating system. But if OBD occurs more regularly under some mating systems, is it likely to be

severe and most importantly is it likely to persist, increasing the probability of detriment to the

population.
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35

While OBD may be severe as in the case of seed abortion or F1 inviability these are generally not

of great concern as OBD will be expressed early and lethally and so there will not be OBD in the

populational sense. What is of concern is the carryover of numerous mildly deleterious alleles

(genetic load) that are capable of being passed to further generations and expressed over an

undetermined time possibly via a dominance-recessive mechanism as has been postulated for

inbreeding depression (Charlesworth and Charlesworth 1987). The finding that inbreeding

depression may persist even in populations of highly selfing species (Karron 1991) is worrisome

because it indicates that these mildly deleterious alleles are maintained even under strong

inbreeding. Other authors hypothesize that inbreeding populations may purge such “genetic

load” once a certain level of inbreeding is reached (Lacy 1992, but see Hedrick 1994). Purging

the genetic load seems likely for those species which have reached a stable strategy of complete

self-fertilization but it appears unlikely to be generally true for all selfing species given the

plasticity of the breeding system under local selective conditions. The point here is that most

species, perhaps with the exception of highly inbreeding species are likely to carry a significant

genetic load. There is abundant evidence that the genetic load of a population is often expressed

under unnatural inbreeding and as such inbreeding depression has been a major focus of

conservation genetics (Lacy 1992). If we assume that NNG’s are likely to (1) add to the genetic

load of a population by carrying additional deleterious alleles and (2) increase OBD by disrupting

coadapted gene complexes rather than be expressed as heterosis then the major concern over

OBD should be on those taxa that are predominately naturally inbreeding.

With respect to local adaptation but there are important differences between selfing and

outcrossing species. For selfing species there are two considerations. Firstly, the genome of a

selfing species is likely to be highly homozygous and any highly deleterious mutations will be

expressed at some time (Hedrick 1994) under intensive inbreeding. Therefore, the importation of

NNG’s are likely to be expressed as severe OBD in the F1 generation and in the case of annuals

there is a remote possibility that population size could be drastically reduced if pollen flow from

established NNG’s is large enough to produce a predominantly unadapted cohort. Secondly,

because the loci may be so tightly linked there is little chance of disrupting coadapted gene

complexes and thus mildly deleterious alleles may be hidden from selection due to limited

recombination (Wolfe 1993). The importation of NNG’s are likely to produce substantial

reorganization of the genome and subsequently gene-environment coadaptations are likely to be

disrupted.

For outcrossing species the heterogeneity of the genome is likely to contain a high genetic load

which often is expressed as severe inbreeding depression under forced selfing. Any number of

deleterious alleles are likely to accompany NNG’s arriving via pollen in natural populations. This

may increase OBD temporarily in a population. Temporal OBD rather than persistent OBD is

expected because it is difficult to see how strongly deleterious alleles could be maintained in any

population. Further, strong linkage among loci in outcrossing species would only be maintained

under strong selection, something not likely for populations that are generally highly variable and

often geographically widespread. This is evident in studies of grasses (Balfourier et al. 1994,

Godt and Hamrick 1998, Warren et al. 1998). The likelihood of persistent OBD due to increased

genetic load under outcrossing would appear to be small since in most situations deleterious

alleles will be exposed to selection after recombination via progeny with low fitness and

additionally the progeny must compete in the population with established (and presumably well

adapted) plants.

Conclusions

No discussion of OBD would be complete without addressing the concept of optimal outcrossing

distances. This concept is important to consider here because optimal outcrossing theory

suggests that a combination of inbreeding and OBD interact to produce an optimal degree of

outcrossing in populations and this may lead to overly emphasizing the potential for OBD. I have

several objections to broadly applying this concept. Firstly, optimal outcrossing distances imply

that these distances are stable and permanently associated with reductions in fitness for long
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

36

outcrosses. The concepts of fitness and selection are best expressed as propensities for certain

evolutionary outcomes (see Mills and Beatty 1994 for discussion) which are not entirely stable or

even predictable. Optimal outcrossing as a populational concept can only be represented

statistically, as optimal outcrossing is the property of individuals not populations. Secondly, the

distance for an optimal outcross depends entirely upon where the individual is with respect to

other individuals in the population. Fitness differences can be averaged over individuals and thus

we create the statistical illusion that the population has an optimal outcrossing distance while in

reality there is great variation in pollination distances achieved by individuals. Additionally such a

optimization theory becomes extremely complicated with fluctuating population densities as is

common among populations of annuals and to some extent perennials.

Waddington (1983) proposes that optimal outcrossing distances may never be achieved by plants

and presents two models of OBD for explanation. Under the “isolation by distance” model, OBD

increases with distance from a source plant because of reduced relatedness caused by limited

gene flow. If selection for longer distance of pollen flow is possible then the zone of inbreeding

depression increases as a consequence. Additionally, as the genetic neighborhood size

increases the effects of inbreeding become less pronounced and so selection should relax,

shifting the “optimum”. It is difficult to see how a plant may manage to maintain an optimal pollen

flow particularly for those species that may need to influence a variety of pollinators or where

pollen flow is passive (wind-pollinated species).

Under the “heterogeneous environment” model, OBD occurs as a consequence of different

selective pressures in different habitat patches (local adaptation to a patch); thus the optimum is

fixed at the boundary of the patch beyond which is the zone of OBD. The optimum depends

entirely upon the position in the patch; those near the edge require a shorter distance than those

near the center. It seems likely that a plant’s pollen flow is subject to selection at fairly gross

levels, that is, under balancing selection for selfing and outcrossing through changes in plant

density and characters associated with flower physiology/physiognomy. The plasticity of such

morphological traits (e.g., protrandry) seems testament to such a possibility. A shifting response

to factors such as pollinator availability, plant density and environmental changes does not

require invoking optimality, just a phenotypic response.

Many arguments regarding the a priori severity of OBD are presented in what I call null-selection

arguments. That is, no role is allowed for selection to reassort the genetic structure upon

outcrossing with NNG pollen. This is especially irritating in light of the evidence of the role of

selection. Additionally, any number of sub-optimal crosses occur frequently, especially in

continuous populations, and these are expressed in varying degrees of fitness loss in individuals,

which are subject to selection. I am not arguing that choices of seed sources can be

indiscriminate without deleterious effects; I am arguing however, that the potential for OBD in

native populations be evaluated in light of the evidence and put in context of the evolutionary

biology.

There is, however, a well founded concern that the widespread use of NNG’s among native

populations may drastically reduce the efficacy of studies of gene flow and divergence utilizing a

priori native populations but this issue cannot be resolved here. Additionally, there is a concern

that the use of NNG’s may result in unintentional disruption of plant-animal interactions, but this

seems plausible only in cases of close plant-animal coevolution or in cases whereby there would

be substantial alteration of phenotypic characteristics, much of which could be avoided by

applying clear taxonomic concepts in choosing sources of genetic stock and choosing stock from

sites that have comparable environments (in the broad sense) such as light cues, similar growing

seasons etc.

The conclusions of this review are that OBD can be predicted for species with some combination

of the following characteristics: annual habit, small population sizes, occur in patchily distributed

habitats, have locally high intraspecific variability (e.g., many segregate taxa), a mainly inbreeding

mating system and/or have very localized patterns of gene flow and dispersal. These general
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

37

characteristics are summed in Table 3.

Table 3. Associations between biological traits and the potential for outbreeding depression.

Trait Low potential for OBD High potential for OBD

Geographic range Widespread Narrow/endemic/rare

Breeding system Outcrossing Selfing

Lifeform Long-lived perennials Annuals

Pollen and seed dispersal Pollen and seed dispersal Short distances (gravity)

Pollination syndrome Wind Animals

Intraspecific variations Few Many

The severity of OBD is less predictable and depends a great deal upon other factors such as

taxonomic concepts, historical components of geographical distribution, and the time periods of

genetic isolation. Severe OBD is predictable for species that exist as small populations in patchy

habitats or those that are naturally highly inbreeding due to the increased likelihood that local

adaptation is strongly promoted by natural selection. The persistence of OBD in populations is

also not very predictable as it depends primarily on the strength and direction of selection in the

local environment; however, when considering the above characteristics there is a strong

inference that OBD as a consequence of increased genetic load is unlikely to persist among

populations of some long-lived perennials. Long-lived perennials may ameliorate OBD through

longer generation times and lengthy periods for producing a new reproductive cohort. Thus even

weak selection may have a significant period to reassort population genetic structure. For

annuals there may be strong selection against unadapted genotypes when the unfit progeny are

fully exposed to selection in each generation. However, in annuals some amount of OBD may

persist under weak selection perhaps facilitated by rapid population turnover as well as chance

sampling events among numerous progeny.

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44

Native Grasslands and Their Wildlife Value in Southern Ontario

Landscapes

Owen Steele1

It is widely believed that the original landscape of Ontario was a vast unbroken forest, however

research conducted by the Natural Heritage Information Centre of the Provincial government’s

Ministry of Natural Resources has concluded that there existed a very diverse mosaic of tall grass

vegetation. This ranged from open grassland to savannahs and even more closed woodlands in

areas not so frequently burned. Currently less than 3% of the estimated grassland extent remains

today. Wetland losses closely mimic that of grasslands as European settlers modified the

landscape to benefit their needs.

Ducks Unlimited Canada’s (DUC) mission is to address these impacts through the conservation

of wetland ecosystems and associated upland habitats to promote a healthy, sustainable

environment for people and wildlife. Upland areas adjacent to wetlands are critical to wetland

dependent wildlife, especially the interface between the two habitats. Waterfowl research

indicates that as many as 80% of upland nesting waterfowl nests are found within 300 m of the

wetland. Thus, land use practices surrounding wetlands have a significant impact (both positively

and negatively) on habitat productivity.

In order to answer questions regarding upland habitat issues, DUC ‘s research branch, the

Institute of Wetland and Waterfowl Research, is presently completing a waterfowl study of various

Southern Ontario landscapes. In each year since 1997, 60 Mallard [Anas platyrhynchos] hens

were implanted with radio telemetry devices to track and monitor their habitat preferences and

reproductive success. In the two years the study was conducted in the agriculturally influenced

portion of Southern Ontario, upland grassland habitat (both tame forage and idled grassland)

proved most attractive to the nesting birds. Nest success was variable based on a number of

interrelated parameters including timing of hay cut, predator species and abundance, along with

grassland habitat considerations such as quality, quantity, and juxtaposition.

In an initial attempt to improve wildlife habitat adjacent to wetlands, DUC planted tame grasses

and legumes. The resultant grassland was found to require regular and expensive management

that frequently compromised the habitat’s wildlife value. These limitations, combined with a

Southern Ontario average annual snowfall that exceeds 250 cm and promotes stand compaction,

motivated DUC to search for better alternatives. Following the lead of DUC in western Canada

who have been utilizing prairie grasses and forbs for more than 15 years, we began investigating

the merits of native plant species that were historically present in Ontario.

With the assistance of many partners, including the USDA NRCS, we tested dozens of warm and

cool season native grass species in plots to determine their suitability for a nesting cover

program. The evaluation progressed from establishment issues to investigations of stand

resiliency and habitat quality, leading us to our current array of warm and cool season species:

Warm Season Grasses Cool Season Grasses

- big bluestem - bluejoint

- little bluestem - slender wheat grass

- switchgrass - northern wheat grass

- sideoats grama - Canada wildrye

- Indian grass

Because our large-scale plantings are usually next to wetlands, we commonly encounter

variability in site conditions. The sculptured seeding technique is an ecological approach to

 

1 Biologist, Ducks Unlimited Canada, 566 Welham Rd., Barrie, ON, L4N 8Z7
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45

revegetation based on matching site capability with appropriate plant species to create a diverse

plant community capable of maximizing wildlife benefits.

Monitoring and Adaptive Resource Management (ARM) is a very important components of our

program. Habitat quality is contingent on having sufficient species diversity to provide both

vertical and horizontal structure as well as field heterogeneity and patchiness.

In addition to numerous studies in the 1980’s that focused on pheasants in New York State, Kerr

in 1987 recorded 16 species of birds nesting in switchgrass stands at Tonowanda including –

Northern Harrier, 3 species of Sparrows (song, swamp, and savannah), Mallard, Blue Winged

Teal and Woodcock. DUC informal studies conducted by volunteer birders combined with other

observations in Ontario have inventoried similar avian species compositions with the common

addition of Meadow Lark and Sedge Wren.

In southwestern Manitoba, the Prairie Habitat Joint Venture (PHJV) assessment study has

documented the effect of upland habitat programs on prairie songbirds. Mixed grassland

plantings of various ages ranked highest in relative abundance of grassland nesting songbirds,

many of which have shown significant population declines in the past several decades. According

to Hartley’s PHJV work in 1994 on passerine abundance and productivity indices, significantly

fewer passerines were found to utilize agricultural lands when compared to remnant and planted

grasslands.

Native grasslands play host to a diverse array of other wildlife species that benefit from this

important habitat for reasons other than nesting. More research will be required to quantify other

species benefits and this will undoubtedly provide additional support for grassland programs. In

addition, understanding the indirect role native grasslands play in conserving wildlife habitats and

benefiting society in general, through such activities as the improvement of water quality and

minimization of soil erosion from water runoff and wind, will greatly enhance the status of native

plants for restoring the overall health of our ecosystems.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

46

Improving Water Quality Using Native Grasses

Ronald R. Schnabel 1

Abstract

Numerous water quality challenges confront the people of the eastern United States. Thousands

of miles of streams and thousands of acres of lakes and estuaries do not fully meet the water

quality standards of their designated uses. The Clean Water Act requires states to devise and

implement plans to bring these waterbodies into compliance. The States within the Chesapeake

basin have agreed, by 2000, to reduce the mass of pollutants entering the Bay to 40% below

1985 levels and then cap them at that level regardless of population or industrial growth. At the

same time, the U.S. Department of Agriculture has started a program (National Conservation

Buffer Initiative) to establish 2 million miles (3 million km) of conservation buffers by 2002. Each

of these efforts to improve water quality will require choices of vegetation. Native grasses should

be strongly considered during planning and implementing water quality improvement projects.

Native grass buffers limit the transport of nonpoint source pollutants within and from fields.

Vegetative barriers of switchgrass [Panicum virgatum L.] and eastern gamagrass [Tripsacum

dactyloides (L.) L.] commonly trap up to 50% of coarse sediment and significant amounts of plant

nutrients within the field. Grassy riparian buffers, either alone or as part of a forested buffer

system, trap or transform sediments and plant nutrients before they enter streams. Native

grasses might also be used in contour filter strips that can retain 50-70% of nutrients, pathogens

and sediment.

Incorporating perennial, native warm-season grasses into farming systems and seeding them in

critical areas further reduces erosion and loss of plant nutrients. Native warm-season grasses

produce large amounts of biomass suitable for forage or as biofuel feedstock with less fertilizer

than other vegetation. Their incorporation into farming systems can reduce inputs to the farm and

the potential for their loss. Native grasses have a place in efforts to improve water quality, both in

limiting the source of pollutants and intercepting pollutants before they enter a waterbody.

Introduction

How we define “water quality” depends on how the water is used and on our proximity to it. For

example, to residents of an upland watershed drained by a high-value, cold-water fishery, stream

temperature, channel and biological community characteristics as well as plant nutrient

concentrations are all important components of water quality. In contrast to the multiple local

concerns, the export of pollutants to a lake or estuary is the principle regional water quality issue

for residents of upland watersheds. Likewise, while the quality of estuaries and lakes has many

facets, the delivery of pollutants is the leading regional concern and will be the focus of the

remainder of this paper.

Water Quality Challenges

Two major water quality challenges currently face the residents of the eastern United States and

they will continue into the next century. In 1987, the Commonwealths of Pennsylvania and

Virginia, the State of Maryland, the Environmental Protection Agency (USEPA) and the

Chesapeake Bay Commission, signed the Chesapeake Bay Agreement establishing a goal of

improving water quality in the Bay to support living resources. A commitment to reduce nutrient

pollution by 40% by 2000 was key to achieving that goal. In 1992, the Executive Council

recommitted itself to reducing nutrient levels by 2000 and then capping nutrient loads regardless

 

1

 USDA-ARS, Pasture Systems & Watershed Management Research Laboratory, University

Park, Pennsylvania 16802
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

47

of continued population, industrial or agricultural growth. The Executive Council reaffirmed that

commitment in 1997.

The Clean Water Act requires that the States implement plans to bring the quality of their water

bodies up to levels established for their designated uses. Section 303(d) of the Act mandates

that States determine the total load of each pollutant that an impaired water body can accept on a

daily basis and still meet water quality standards for its designated use. The States must further

apportion current loads among the various sources, develop and then implement plans to reduce

total loads below maximum permissible levels.

How are we doing?

Phosphorus (P) and nitrogen (N) are the major plant nutrients of concern in the Chesapeake Bay.

The Susquehanna, Potomac and James River watersheds are the largest in the Bay drainage

and contribute the greatest quantities of water, P, and N (Figure 1). Monitoring data showed an

overall decline in P entering the Bay from 1987-1992, with substantial reductions from the

Susquehanna and Potomac watersheds (USGS 1995). These reductions in P delivery to the Bay

were largely attributable to improvements at point sources, for example at sewage treatment

plants. More recent data, while not yet clear, may show a reversal in the P trend as increases in

nonpoint source P losses offset previous reductions in point source P. Nitrogen delivery to the

Bay continued to rise, although at a lower rate than earlier in the decade. Improvements in

sewage treatment technology and changes in detergent formulation that caused a major

reduction in point source P did not, and were not, expected to cause similar reductions in point

source N. Later data show that both N and P levels declined between 1985 and 1997 when

adjusted for year-to-year differences in flow (Chesapeake Bay Program 1999). Computer

simulations indicate that basin-wide acceptance of best management practices (BMP), to control

nonpoint N sources, and the adoption of biological nutrient reduction (BNR) at wastewater

treatment plants, will reduce N delivery to the Bay below the 40% reduction goals sometime after

2000 (Chesapeake Bay Program 1999). The full extent of N reductions achievable from

widespread use of BMPs are not yet measurable at the Bay, because most of the N exported to

the Bay enters streams as discharging ground water. Ground water residence times in parts of

the Basin are long, perhaps decades. Thus, some of the water currently entering the Bay has an

N load that reflects management prior to the adoption of BMPs, and the total improvement will not

be measurable for some time. Even if reductions in N delivery continue to work their way through

the ground water system, we must recognize that to meet the year 2000 goals and certainly to

cap loads at that level, greater efforts must be made to reduce both N and P entering the Bay.

The largest sources of both N and P to the Bay are still nonpoint sources of agricultural origin

(Table 1), and we must expect that the agricultural sector will be asked to do more.

Throughout the eastern US the states must evaluate their waters, sort them into 4 categories

relative to their intended uses, and report the results to the USEPA. In 1992, only 56% of

assessed stream miles across the country fully supported their designated uses. Siltation and

plant nutrients were the two most common reasons for lack of compliance, with 45% of the

assessed streams having too much sediment and 37% having excessive levels of nutrients.

Twenty-one thousand waterbodies were listed as not fully supporting their designated uses in the

1998 reports to the USEPA (USEPA 1999). They accounted for 300,000 miles (482,700 km) of

stream or shoreline and 5 million acres (2 million hectares) of lake or estuary. Approximately 220

million Americans live within 10 miles (16 km) of an impaired waterbody. The most common

causes of impairment were still excessive levels of sediment, plant nutrients, and pathogens.

These high levels of noncompliance are the sum of the categories fully supporting but threatened,

partially supporting, and not supporting. While much progress has been made in educating the

public and in improving water quality over the last decade, the levels of noncompliance show that

much remains to be done.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

48

Figure 1. Percentage of water, nitrogen and phosphorus exported to the Chesapeake Bay from

the major tributaries.

Table 1. Nutrient export to the Chesapeake Bay (Chesapeake Bay Program 1998).

Source Area N P

%

Non-point 100 76 74

Forest 58 17 5

Agriculture 33 44 58

Urban 8 10 10

Point - 24 26

Pollution Control Options

Whether we focus on the Chesapeake Bay or take a broader view, we find many water quality

problems caused by nonpoint source pollutants. There are essentially two ways to control

nonpoint source pollution. It can be controlled at the source by management that reduces

erosion and closely matches the timing and concentration of plant nutrient availability with crop

requirements, or it can be intercepted before it enters an impaired waterbody. Whenever

possible, it is preferable to control pollution at the source by improved nutrient management and

reduced tillage. However, given inefficient nutrient use by crops, vagaries of the weather, and

current high to excessive levels of plant nutrients in many soils, transport control is a necessary

component of water quality improvement strategies. Many of the options available to land

managers require them to select appropriate vegetation. Native warm-season grasses can be

used effectively to reduce the potential for NPS pollutant loss (source control), and to contain

pollutants within the field or watershed (transport control).

Source Control

The goal of source control is to reduce the potential for pollution by reducing the addition of

nutrients to the field, by applying them in a less mobile form, and by keeping the soil in place.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

49

Eastern native grasses can be used a number of ways to reduce the source of pollutants.

Eastern native grasses are perennial with deep, dense root systems. Thus erosion and the

transport of sediment associated pollutants will be diminished, especially compared to cropped

soils. These deeply rooted perennial grasses also enhance infiltration that reduces runoff and the

potential loss of dissolved pollutants (i.e., phosphorus) that are only slightly soluble in the soil.

Many native warm-season grasses are well adapted to droughty, acidic, and infertile soils, and

they require much less N and P to produce more biomass than similarly located cool-season

grasses (Table 2). These grasses could be used in the planting of critical areas, such as those

that are especially erosive or are locations most likely to lose applied nutrients.

Table 2. Biomass yields for selected native warm-season grasses and adapted cool-season

grasses. Sharp and Gates (1986).

Grass w/o fertilizer 75 kg N ha-1

Mg ha-1 Mg ha-1

Native Grasses

 Niagara big bluestem [Andropogon gerardii Vitman] 4.4 6.8

 Blackwell switchgrass [Panicum virgatum L.] 4.2 7.9

 NJ50 switchgrass [Panicum virgatum L.] 10.7 11.2

 NY591 Indiangrass [Sorghastrum nutans (L.) Nash] 5.2 6.2

Adapted grasses

 KY31 tall fescue [Festuca arundinacea Schreb.] 0.8 3.8

 Reed canarygrass [Phalaris arundinacea L.] 1.6 3.9

 Pennlate orchardgrass [Dactylis glomerata L.] 1.3 3.1

Beef cattle and sheep grazing native grasses as part of their diet gain as much as or more than

animals grazing cool-season grasses (Jung 1986; Reid et al. 1988a; Reid et al. 1988b). By

incorporating native grass pastures farmers could maintain or increase the productivity of their

farms while reducing the need for nitrogen and phosphorus additions. Since native grasses

utilize nutrients as efficiently as cool-season grasses (Staley et al. 1991), reduced additions

should translate directly into reduced losses from the watershed.

Using native grasses as energy crops has been studied extensively (e.g., Hohenstein and Wright

1994; Sanderson et al. 1996; McLaughlin and Walsh 1998; Walsh 1998), and the net energy

produced with these grasses ranks near the top of all biofuels. Current markets for energy crops

are small. However, markets will continue to increase as energy conversion technology

improves, making the economics of biofuels more competitive with fossil fuels, and in response to

environmental concerns over atmospheric concentrations of carbon dioxide. Conversion of

cropland to native grasses to supply the emerging biofuels market has the potential to decrease

the amounts of plant nutrients that are transported to surface and ground water.

Transport Control

The National Conservation Buffer Initiative is one program in which native grasses can be used to

diminish the adverse impacts of agriculture on water quality by controlling the transport of

pollutants to streams. The initiative, administered by the Natural Resources Conservation

Service (NRCS), has the goal of establishing 2 million miles (3 million km) of conservation buffers

by 2002. Conservation buffers are small areas or strips of land in permanent vegetation designed

primarily to intercept pollutants. Conservation buffers include vegetative barriers, contour grass

strips, riparian buffers, and grassed waterways. Each of these practices controls pollutant

transport by slowing water runoff, trapping sediment, and enhancing infiltration within the buffer.

Conservation buffers have been shown to remove 50% or more of nutrients and pesticides, 60%
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

50

or more of certain pesticides, and 75% or more of sediments. Combined with appropriate upland

treatments, buffers should allow farmers greater economic and environmental sustainability. This

and other conservation efforts occur at a time when governmental directives strongly encourage

using native plants in revegetation programs.

While each of these conservation measures has been practiced in the U.S. and around the world

for many years and their effectiveness is well documented, most of the information has been

gathered for adapted, non-native species. Vegetative barriers, grass hedges, are an exception

for which over a decade of research exists using grasses native to the eastern U.S.

Vegetative Barriers

Vegetative barriers are parallel strips of stiff, erect, dense grass planted close to the contour and

across concentrated flow areas. They are usually about 3 feet (1 m) wide with hundreds of stems

per square foot. Soil berms that develop during the use of vegetative barriers, in contrast to

those that build up around other buffers, do not hinder buffer performance and do not need to be

smoothed out during maintenance operations.

The coarse, stiff grasses of vegetative barriers can withstand high water flows and pond runoff.

As the water ponds above the barrier, concentrated flows are slowed and spread, reducing the

erosive energy of the runoff. Sediments settling out of the ponded water fill areas of concentrated

flow and generally reduce the slope between hedges. The erosive energy of runoff is further

reduced by enhanced infiltration within and ahead of the barrier before it enters the next crop strip

or associated conservation buffer.

Vegetative barriers are reported to remove from 40 to 60% of sediment and sediment-associated

chemicals from runoff (Meyer 1995; Meyer et al. 1995; Dabney et al. 1995). Numerous factors

affect the pollutant trapping efficiency of vegetative barriers. Land slope affects trapping

efficiency and, therefore, vegetative barriers are not recommended on slopes greater than 10%

(NRCS 1997b). The distribution of particles or aggregate sizes entrained in runoff is the

predominant soil characteristic affecting hedge effectiveness. While over 90% of aggregates

larger than 125 microns settle in pools formed by hedges, only 20% of aggregates or particles

smaller than 32 microns are trapped (Dabney et al. 1995). Consequently, vegetative barriers are

not very effective where a large fraction of eroded material is silt or clay sized. The physical

strength and resilience of the hedges also affect trapping efficiency. The strength to resist the

force of concentrated flow and create a large pool in front of the hedge, and the ability to flex

instead of break when the force becomes too great, is a prime consideration when choosing

grasses for hedge plantings. Switchgrass [Panicum virgatum L.] and eastern gamagrass

[Tripsacum dactyloides (L) L.] are two grasses native to the eastern U.S. that possess these

characteristics and are commonly used in vegetative barriers (Dunn and Dabney 1996).

Filter strips

Filter strips and grass waterways are some of the older, most tested conservation practices. In

contrast to vegetative barriers, they are wider, less dense strips of grass designed to allow runoff

to move through them and trap pollutants within them. They remove 70-90% of sediment and

associated contaminants, infiltrate 20-60% of runoff and dissolved contaminants, and transform

entrapped contaminants. While most of what we know about the effectiveness of filter strips and

their management we learned from strips planted to naturalized, non-native grasses, native

warm-season grasses are being included in filter strip studies. Mersie et al. (1999) reported that

switchgrass filter strips retained the herbicide atrazine and metolachlor by enhancing infiltration.

If appropriately managed, filter strips of native eastern grasses may be as effective as non-native

grasses, but that has yet to be demonstrated.

Buffers designed to slow runoff and keep sediment in the field are most effective in controlling

sediment-associated contaminants. By enhancing infiltration, they also control dissolved
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

51

contaminants such as phosphorus that are only slightly soluble in the soil. Since most nitrogen

enters streams as nitrate, and nitrate is soluble in the soil, these practices have little positive

affect on nitrogen delivery to streams. In fact, practices that enhance infiltration might increase

nitrogen delivery to the stream by transporting more nitrate through the soil into ground water.

Riparian buffers

Riparian buffers are the last place on the watershed where sediment associated contaminants

can be removed from runoff before it enters the stream or lake. Since most ground water

discharges to streams in the riparian zone, they are also the only buffers that can remove nitrate

from discharging ground water. The NRCS (NRCS 1997a) recommends a 3 zone forested

riparian buffer system (Figure 2). The buffer system is designed to remove most of the P and N

in the managed wooded strip (zone 2). The grass strip (zone 3) is designed to spread

concentrated flow and control erosion.

Figure 2. Schematic of the riparian buffer system recommended by the NRCS (NRCS 1997a).

In contrast to forested riparian buffer systems, many streams have an entirely grassy riparian

buffer. Nutrient removal by riparian buffers with different vegetation has rarely been compared;

however, where wooded and herbaceous buffers have been compared they were similarly

effective (Haycock and Pinay 1993; Osborne and Kovacic 1993). Denitrification, an important

process in eliminating N from discharging ground water, is generally higher in grassed riparian

buffers than in wooded buffers (Groffman et al. 1991; Haycock and Pinay 1993; Schnabel et al.

1997). Both forested riparian buffer systems and herbaceous riparian buffers can remove 50-

90% of sediment, N, and P.

Sediment and P removal in riparian buffers depends on the same factors as for in-field buffers:

buffer width and slope, and elimination of concentrated flow. Nitrogen removal in riparian buffers

Zone 3

Zone 2

Zone 1

Concentrated

flow erosion

Erosion must be

controlled in the

area
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

52

depends largely on subsurface hydrology. Where the subsurface flow system is shallow and most

ground water discharges through an extensive shallow layer in the riparian buffer, substantial

reductions in nitrate concentrations have been measured, regardless of vegetation. Where flow

systems are deeper and much discharging ground water spends little time in biologically active

parts of the riparian zone, N transformation causes small or no reductions in nitrate concentration.

In a study in central Pennsylvania (Schnabel, 2000), nitrate concentrations in shallow ground

water under a cornfield were >10 mg l-1. Shallow ground water discharging into the stream had a

nitrate concentration of ~0.5 mg l-1. This site was located on a floodplain, had a 30 foot (9 m)

grass riparian buffer and a flow restrictive layer at a depth of 10 feet (3 m). Much of the change in

nitrate concentration occurred in the cornfield, upgradient of the buffer, because conditions

created by a shallow, fluctuating water table supported rapid denitrification. Denitrification rates

in the grass buffer were greater than in a wooded section of buffer along this stream (Schnabel et

al. 1996). Despite the low streamside ground water nitrate concentration, nitrate concentrations

in the stream were from 3 to 5 mg l-1, indicating that the conditions found at this floodplain site are

not common in the watershed. Additionally, nitrate concentrations were virtually unchanged

through the riparian buffer at two other locations in Pennsylvania with deeper subsurface flow

systems (Schnabel, unpublished data).

None of these evaluations of grass riparian buffers used native grasses. Consequently,

projections of how riparian buffers of native grasses will function are made from a small base of

information. One study evaluated denitrification rates under wooded riparian buffers, buffers in

adapted cool-season grasses, and native, warm-season grass (switchgrass) buffers (Schnabel

and Genito 1999). We found no difference in average denitrification rates under the different

types of vegetation at sites in Maryland and Virginia. These data suggest that native grass

buffers may be as effective as wooded or adapted grass riparian buffers in removing nitrate from

discharging ground water. It should be said that both the highest and lowest rates of

denitrification were measured under the switchgrass buffers. The difference may be a varietal

difference where switchgrass with a higher protein content and lower C/N ratio will support higher

rates of denitrification and accumulate more N in biomass.

Watershed-Scale Considerations

From the discussion above we see that native grasses could be used in a variety of ways to

either reduce the source of contamination or to intercept contaminants before they enter streams.

How they might best be used depends on some watershed characteristics.

Most of the N exported from watersheds enters the stream in discharging ground water during the

dormant season. Nitrogen leaches to ground water across the entire watershed and the mass of

N leached can be predicted from land use. Since vegetative barriers, filter strips, and grassed

waterways are designed to control erosion and surface runoff they have little positive impact on N

loss from the watershed. As stated above, since they enhance infiltration, these conservation

buffers could actually increase N leaching to ground water and its subsequent export from the

watershed. Riparian buffers can remove N from discharging ground water if hydrologic conditions

outlined above are met, conditions that are more common to parts of the Atlantic Coastal Plain

and some glaciated watersheds. Overall, changing land use from nutrient intensive agriculture is

the most reliable way to use native grasses to control N loss.

In contrast to N, most P is lost in surface runoff. In watersheds where rainfall rates rarely exceed

the soil’s intake rate, runoff occurs from small predictable areas on the watershed close to a

stream. In these watersheds, more common to the Ridge and Valley physiographic province, P

loss is most directly controlled by managing runoff-producing zones as critical areas and planting

crops that control erosion and require little P, perhaps native grasses. Where soil intake rates are

commonly less than rainfall rates, runoff and erosion occur over the entire landscape and any of

the conservation buffers as well as source control could be used to reduce P export from the

watershed
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

53

References

Chesapeake Bay Program. 1999. The State of the Chesapeake Bay: A Report to the Citizens of

the Bay Region. EPA 903-R99-013, CBP/TRS 222/108. October, 1999.

Dabney, S M., L.D. Meyer, W.C. Harmon, C.V. Alonso, and G.R. Foster. 1995. Depositional

patterns of sediment trapped by grass hedges. Trans ASAE 38:1719-1729.

Dunn, G.H. and S.M. Dabney. 1996. Modulus of elasticity and moment of inertia of grass hedge

stems. Trans ASAE 39:947-952.

Groffman, P.M., E.A. Axelrod, J.L. Lemunyon, and W.M. Sullivan. 1991. Denitrification in grass

and forest vegetated filter strips. J. Environ. Qual. 20: 671-674.

Haycock, N.E., and G. Pinay. 1993. Groundwater nitrate dynamics in grass and poplar vegetated

riparian buffer strips during the winter. J. Environ. Qual. 22: 273-278.

Hohenstein, W.G. and L.L Wright. 1994. Biomass energy production in the United States: an

overview. Biomass and Bioenergy 6:161-173.

Jung, G.A. 1986. How warm-season grasses perform in the Northeast. In: Warm-season grasses:

balancing forage programs in Northeast and southern corn belt. Soil Conservation Society of

America, Ankeny, Iowa.

McLauhlin, S.B. and M.E. Walsh. 1998. Evaluating environmental consequences of producing

herbaceous crops for bioenergy. Biomass and Bioenergy 14:317-324.

Mersie, W., C.A. Seybold, C. McNamee and J. Huang. 1999. Effectiveness of switchgrass filter

strips in removing dissolved atrazine and metoachlor from runoff. J. Environ. Qual. 28:816-821.

Meyer, L.D. 1995. Sediment-trapping effectiveness of stiff-grass hedges. Trans ASAE. 38:809-

815.

Meyer, L.D., S.M. Dabney and W.C. Harmon. 1995. Sediment-trapping effectiveness of stiff grass

hedges. Trans ASAE 38:809-815.

NRCS. 1997a. Riparian forest buffer, Conservation practice standard 391A. National Handbook

of Conservation Practices. USDA-NRCS.

NRCS. 1997b. Vegetative barriers, Interim conservation practice standard 601. National

Handbook of Conservation Practices. USDA-NRCS.

Osborne, L.L., and D.A. Kovacic. 1993. Riparian vegetated buffer strips in water-quality

restoration and stream management. Freshwater Biology. 29: 243-258.

Reid, R.L., G.A. Jung and W.V. Thayne. 1988a. relationships between nutritive quality and fiber

components of cool-season and warm-season forages: a retrospective study. Journal of Animal

Science 66:1275-1291.

Reid, R.L., G.A. Jung and D.W. Allinson. 1988b. Nutritive quality of warm-season grasses in the

Northeast. Bulletin 699. West Virginia University Agricultural and Forestry Experiment Station.

Morgantown, WV.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

54

Sanderson, M.A., R.L. Reed, S.B. McLaughlin, S.D. Wullschleger, B.V. Conger, D. Parrish, C.

Taliaferro, W.R. Ocumpaugh, M.A. Hussey, J.C. Read, and C.R. Tischler. 1996. Switchgrass as a

sustainable bioenergy crop. Bioresource Technology 56:83-93.

Schnabel, R.R. 2000. Characterization of riparian zone sites for NPS pollution abatement: case

study in central Pennsylvania. Agriculture, Ecosystems and Environment (accepted).

Schnabel, R.R. and D. Genito. 1999. Riparian denitrification and organic carbon status.

Agronomy Abstracts pp. 229.

Schnabel, R.R., L.F. Cornish, J.A. Shaffer and W.L. Stout. 1997. Denitrification distributions in

four Valley and Ridge riparian ecosystems. Environmental Management 21:283-290.

Schnabel, R.R., L.F. Cornish, W.L. Stout and J.A. Shaffer. 1996. Denitrification in a grassed and

a wooded, valley and ridge, riparian ecosystem. J of Environmental Quality 25:1230-1235.

Sharp, W.C. and G.A. Gates. 1986. Why use warm-season grasses in the corn belt and

Northeast? In: Warm-season grasses: balancing forage programs in Northeast and southern corn

belt. Soil Conservation Society of America, Ankeny, Iowa.

Staley, T.E., W.L. Stout and G.A. Jung. 1991. Nitrogen use by tall fescue and switchgrass on

acidic soils of varying water holding capacity. Agronomy Journal 83:732-738.

USEPA. 1999. Talking Points: Proposed Regulations, Total Maximum Daily Loads. Office of

Water. Watershed Program, Total Maximum Daily Load (TMDL) Program.

http://www.epa.gov/owowwtr1/tmdl/tptmdl.html.

USGS. 1995. Chesapeake Bay: Measuring Pollution Reduction. U.S. Department of the Interior,

U.S. Geological Survey, Fact Sheet FS-055-95. http://water.usgs.gov/wid/html/chesbay.html

Walsh, M.E. 1998. U.S. bioenergy crop economic analysis: status needs. Biomass and Bioenergy

14:341-350.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

55

Landscape and Design Issues with Natives

Neil Diboll1

The utilization of native prairie plants in home landscapes and commercial settings has grown

steadily over the past two decades. One of the primary reasons for this increase is due to

changes in people’s perceptions of native plants. Formerly regarded as “weeds”, many native

plants have now attained acceptances in our gardens and landscapes, as people have come to

know them. Benefits include long-term maintenance cost savings, reduced fertilizer and pesticide

usage, elimination of irrigation, and creation of wildlife habitat while restoring a portion of our

natural heritage.

People tend to view native plantings as “weedy” due to the apparent chaos of a prairie meadow.

As in nature, plants in the landscape associate themselves together in a mixed, diverse plant

community. The lack of a formal garden design requires a re-orientation of esthetic perceptions

in order to appreciate the meadow. The hand of the human species does not prevail in the

structure of a meadow garden. It is indeed a “Joint Venture with Nature” wherein natural

ecosystem models are used as the guideline for the landscape.

Plant selection is another important factor in the growing acceptance of utilizing native prairie

plants in the landscape. Most homeowners prefer relatively short plants around their dwelling

spaces. Since many of the flowers and grasses of the prairie are tall (5 to 12 feet), they are not

acceptable in a home garden setting. By planting shorter species (less than four feet tall), people

feel more comfortable in meadow landscapes. To address this concern, seed mixes have been

selected that are composed of flowers and grasses that grow only a few feet tall. These short

mixes are more popular than tall prairie mixes for home landscapes and commercial plantings.

Prior to widespread acceptance of prairie-style landscapes in the Upper Midwest, numerous

battles, in court and in city hall, were waged between the “Weed Ordinance Enforcement”

proponents and the “Natural Landscape” proponents. The overwhelming result of these conflicts

has been the acceptance of natural landscapes, provided they are properly planned, installed,

and maintained. The realization that native landscapes require little or no fertilizer, pesticides, or

irrigation, while attracting a tremendous diversity of birds and butterflies, has made them an

increasingly popular choice for a variety of landscape applications.

A significant obstacle preventing the more widespread adoption of native prairie landscapes is the

requirement of thorough weed control prior to planting. Due to the relatively slow rate of

maturation of these native perennials, perennial weeds must be eliminated completely, prior to

seeding. This can be a long process, sometimes requiring a full year or longer. After seeding,

annual and biennial weeds often dominate in the first two growing seasons. The entire process of

prairie establishment typically requires three to four years to achieve a mature, blooming

meadow.

Although a prairie meadow is composed of long-lived perennial flowers and grasses that return

year after year, it is by no means an “instant gratification” landscape. Many people think twice

before embarking on such a long landscape journey. Landscaping with native plant meadow is

for those who wish to invest in the long-term ecological health of their land. It is not for people

who want to see pretty flowers two months after they till up the ground and scatter the seed.

A common concern is that dense stands of prairie grasses and flowers might promote wildlife

habitat for certain “less desirable” animal species, such as insects, mice, and snakes. Native

grasslands do indeed create habitat for a variety of animal life. These in turn are fed on by the

owls, hawks, foxes, and other predators. A balance of nature is maintained, and many forms of

 

1

 Prairie Nursery, P.O. Box 306, Westfield, WI 53964
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

56

life are provided homes by the prairie meadow gardener. For those who do not wish to attract a

variety of wildlife to their property, a prairie meadow may not be a good choice.

Finally, prairie management is not for the faint of heart. The preferred method of managing

established prairie meadows is the use of controlled burning to discourage woody plants and

invasive exotic plants. Some people embrace the fire management program with enthusiasm,

while other shrink in trepidation and fear. With proper planning and foresight, firebreaks can be

designed into the landscape so that they are in place in advance of initiating a controlled burn.

By following proper safety precautions, fire is a cost-effective landscape management tool that

almost anyone can learn how to use safely. In the event that burning is not an option, mowing

can be substituted as a reasonably effective second choice.

Thus, the main obstacles to more widespread use of native grasslands in the landscape include:

$ Perception of chaotic, “weedy” appearance.

$ Some native prairie plants get too tall.

$ Takes too long to establish.

$ Might attract unwanted wildlife.

$ Fear of managing with controlled burning.

These concerns are addressed by:

$ Designing prairie seed mixes with attractive flowers and grasses that fit into the

surrounding landscapes.

$ Using shorter plants, less than four feet tall.

$ Educating people on the long-term benefits of native meadow plantings, including

reduced chemical use, no irrigation, pest-resistance, lower maintenance, and significant

long-term cost savings.

$ Focusing on the beneficial wildlife attracted to meadows, and the value of restoring the

ecosystem as a whole.

$ Providing educational information on prairie management using controlled burning, and

using mowing management as an alternative to fire.

As more people plant native plant prairies, these habitats are becoming increasingly accepted as

an alternative to high maintenance, intensively managed landscapes that rely on herbicides,

pesticides, and irrigation. The natural beauty of prairie landscapes has won many converts. The

added benefit of the birds, butterflies, and other wildlife that visit native meadows is a strong

motivator for many people to establish a prairie. Restoring the land to a healthy, functioning

ecosystem that is in harmony with nature is another big reason prairies. With the long-term time

and cost savings that are realized from reduced maintenance of native meadows, there are more

reasons to plant a prairie.

Reference:

Diboll, N. 1986. Mowing as an alternative to Spring burning for control of cool season exotic

grasses in prairie grass plantings, pp. 204-209. In: Proceedings of the Ninth North American

Prairie Conference, Tri-College University Center for Environmental Studies, Moorhead,

Minnesota.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

57

Ecosystem Restoration May Prairie State Natural Area

Brian Bowen1

Abstract

Ecosystem restoration begins by recognizing function and identifying the ecosystem properties

that drive the process. These properties are the biotic and abiotic factors necessary for

ecosystem function to occur. Completing basic research and identifying reference natural areas

is a first step in identifying restoration goals. These goals identify restoration conservation targets

(communities, rare species, etc.) so that objectives can be developed to prioritize actions or

tasks. These objectives should be measurable through monitoring and have the flexibility to

enable adaptive management actions. A site assessment of biotic factors identifies these

restoration targets including the plant community types, rare species, and any critical keystone

species for the site. An abiotic assessment identifies essential influences including disturbance

regimes, substrate, hydrologic features, and topography that support the biotic elements. These

assessments provide the information to determine the richness or intactness of the ecosystem,

threats, and restoration feasibility.

This approach is presently underway at May Prairie Designated State Natural Area in Coffee

County, Tennessee. It is a part of the larger landscape scale barrens restoration initiative for the

Southeastern Highland Rim of the Interior Low Plateau Physiographic Province. The May Prairie

restoration effort has identified the oak barren community types of the oak barren grassland

ecosystem and its 25 rare species as restoration conservation targets. The goal is to restore the

associated community types for this ecosystem and protect its rare species. A remnant intact

ecosystem on site is the reference area. Research has identified fire as an essential influence on

ecosystem function. Site assessment has determined that hydrologic function has been

disrupted, successional red maple forest and converted pastureland has displaced wet to mesic

tall grass barrens, and understory growth in the shrub layer has altered the oak barrens

community structure. The restoration objectives are to restore hydrologic function by a series

corrective tasks including the removal of red maple, control of fescue in the pasture to release

native vegetation, and reduction of the shrub layer in the oak barrens community. Monitoring is

ongoing and management actions are adaptive. Fire has been reintroduced into the ecosystem.

Restoration is long term in scope and will contribute to the barren restoration effort for this region.

 

1 Administrator and Ecologist, Tennessee Natural Areas Program, Division of Natural Heritage,

Tennessee Department of Environment and Conservation L & C Tower, 14 Fl., 401 Church St.,

Nashville, Tennessee 37243-0447
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

58

Native Warm-Season Perennial Grasses: The Unrealized Potential as a

Forage Crop

Richard W. Taylor1

During discussions with the symposium organizers, it became clear that the species of most

interest were the native warm-season grasses (NWSG). The species of particular interest were

switchgrass [Panicum virgatum L.], big bluestem [Andropogon gerardii Vitman], little bluestem

[Schizachyrium scoparium (Michx.) Nash], Indiangrass [Sorghastrum nutans (L.) Nash], and

eastern gamagrass [Tripsacum dactyloides (L.) L.]. A look at the distribution of each of these

species, shows that at the time of European settlement of America NWSG covered much of the

Eastern United States and would have been available to the European settlers. Another species

native to the United States was reed canarygrass [Phalaris arundinacea L.]. It is a cool-season

grass (CSG) and is quite productive and could have been competitive against introduced CSG.

However, the distribution of the grass did not include coastal Virginia, Maryland, New Jersey,

New York, Connecticut, and Massachusetts (Stubbbendieck et al. 1997). Its distribution plus

other problems discussed below precluded it from consideration by the early colonists and helped

contribute to the eventual dominance of the introduced CSG.

Although we think of big bluestem, little bluestem, Indiangrass, eastern gamagrass, and

switchgrass as natives of North America, the centers of origin for the tribes they represent

(Andropogoneae and Paniceae) were the warmer parts of the eastern hemisphere, possibly in the

East African-Madagascar region (Hartley 1959a,b). The Andropogoneae developed in tropical

climates with a high midsummer rainfall or monsoonal climate pattern while the Paniceae

developed in the equatorial zone with high summer temperatures. The distribution of the

Paniceae in the United States shows a close relationship to winter temperature and especially to

annual rainfall. Species and genera of Andropogoneae spread more recently to the Western

Hemisphere than the Paniceae and have not yet attained their full development. Especially along

the eastern edge of the continent where the warm waters from the Gulf Stream have a significant

influence, the unique climates have led to the development of NWSG that use the growing

season characteristics of the Eastern United States to full advantage.

Although the genera of the tribe, Andropogoneae, are relatively new to North America, individual

species evolved here with adaptations suited to this climate. With species from the tribe,

Paniceae, these adapted species were the established grasses when the first European colonist

arrived in the New World.

The most notable characteristics of the most productive NWSG were late spring initiation of

regrowth, rapid early- and mid-summer growth, mid-summer flowering, tall growth habit, and

bulky seed unreliable for germination the year following harvest. The primary native, productive

CSG, reed canarygrass, was not present in the coastal areas of Virginia or Massachusetts in

colonial times (Stubbendieck et al. 1997), and until recent cultivar improvements through plant

breeding, this grass contained high alkaloid levels that caused palatability and animal

performance problems.

The reaction of European colonists to the native grasses can possibly be characterized as

follows: already used to having grasses grow during milder interludes of winter and initiating rapid

growth in early spring, the colonists may have perceived the growth habit of NWSG as

undesirable. Other traits, unsuited to their farming and grazing practices, became obstacles to the

incorporation of native grasses into farming operations. The difficulties European settlers

experienced in establishing these native grasses after forests were cleared provided additional

impetus towards their tendency to introduced CSG.

 

1

 Extension Agronomist, University of Delaware, Newark, Delaware
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

59

The tall growth habit of the native grasses also may have been perceived as detrimental. The

colonists’ style of grazing which might be described as continuous mob grazing at a set and

relatively low stocking rate was very unsuited to the growth characteristics of the NWSG and

would not have eliminated problems caused by excessive plant height. As relations with the

native Indian tribes deteriorated into sporadic warfare, there arose an increased need to keep

nearby pastures and hay fields closely cropped in the summer months during danger periods.

The amount of labor required to harvest enough hay to last the winter had three impacts. First,

the single hay harvest available from NWSG may have discouraged its use. Second, the length of

time required to harvest hay in colonial times meant that hay quality of the NWSG could have

fallen below the level the animals needed to maintain themselves over the winter. Hay from

NWSG certainly would not have compared favorably with hay from introduced CSG that colonists

were used to feeding. Third, not only did the lower hay quality necessitate the accumulation of

more hay than expected but the delayed spring initiation of growth also increased the need for

hay plus additional labor and materials to increase storage capacity.

The final obstacle involves the grazing techniques used by the colonist and still in play today.

Animals were generally grazed in a commons area on a continuous basis. Techniques such as

continuous mob grazing and constant stocking rate that resulted in variable grazing intensity were

ill suited to NWSG long-term survival.

Native Warm-Season Grass Usage Survey

In preparation for this symposium, a survey was conducted via email involving Natural Resources

Conservation Service (NRCS) personnel (nationwide) and Extension and research forage

agronomists located in states east of the Mississippi River. The first part of the survey requested

information on the number of acres of NWSG planted in their county, region, or state and what

was the intended use of the plantings. Since some plantings could be put to multiple use the

percentages for usage can add up to more than 100 percent. The second part asked participants

to rank a number of factors in order of importance from 1 (being most important) to 5 (being least

important). Some respondents ranked the factors from first to last. If the number exceeded 5, the

author arbitrarily grouped the responses to reflect a ranking from 1 to 5.

Acreage of NWSG

Table 1a lists the acreage estimates received for 25 states in the upper mid-West, northeast, midAtlantic, and southern regions of the country (considered as the eastern region with the remaining

states as the western region). In some cases, state estimates were supplied by survey

respondents and in other cases the acreage is reported for a specified number of counties in the

state. If multiple state estimates were received, the estimates are presented as a range and the

mean of the answers is also reported. It will be noted that in come cases, for example Maryland

and Virginia, a few counties reported more acres than reported for the entire state. All acreage

estimates should be read with some degree of skepticism.

Table 1b contains the acreage estimates from the remaining states that responded to the survey

(labeled as the western region). A state estimate was only reported for Nebraska. For Iowa,

thirteen counties reported both acres and usage but a 26 county region in the northwest reported

usage but not acreage.

Results are reported by region. The eastern U.S. consists of the following states: ME, NH, VT,

MA, CT, NY, PA, OH, MI, WI, WV, NJ, DE, MD, VA, TN, KY, GA, NC, SC, FL, AL, MO, AK, and

MS. Table 1a presents acreage data from the eastern region and Table 1b from the western

region that consists of all remaining states.

For the eastern 25 states (using the mean of answers or sum of county acreage if that was

larger), respondents reported 59,000 acres of switchgrass, 40,000 of big bluestem, 22,000 of

Indiangrass, 6,900 of eastern gamagrass, 42,000 of little bluestem, 258,000 of mixtures of the

above species, and about 91,000 acres of other native grasses (Table 1a). Surveys also were

received from NRCS personnel western states although in fewer numbers. Acreage reported for

the western states is reported in Table 1b along with notes on the number of counties responding
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

60

in a particular state. Mixtures of switchgrass, big bluestem, and Indiangrass and native prairie

were much more common for this region compared to the eastern states.

Impediments to Adoption of NWSG

Survey respondents were asked to rank in order of importance the following factors that might

impede adoption of NWSG. The factors ranked were grower perception of lower forage quality for

NWSG versus cool-season grasses, intake limitations with NWSG due to higher fiber content,

expense and availability of seed, establishment unreliability, grazing management concerns and

problems, and hay management concerns and problems. Under establishment reliability, grazing

management, and hay management, respondents ranked a number of other factors related to the

main problem.

Ratings for the factors involved in adoption of NWSG (Tables 2 to 6) are presented for both

regions although the discussion below concentrates on the results from the eastern region. There

were only minor changes in the rankings of the factors between the East and the West.

Establishment Difficulty: The most important factor inhibiting adoption of the NWSG was

establishment reliability (Table 2). After establishment reliability, seed expense/availability was

next in importance. These two factors switched in ranking between the East and West regions

with seed expense/availability most important in the West. The remaining factors in order of

importance from most to least were knowledge of grazing management techniques, quality

perceptions for NWSG, knowledge of hay management techniques, and intake limitations. These

four factors were ranked in the same order of importance in both regions.

Survey participants were asked to rank a number of factors that could limit establishment

reliability of the NWSG. Their concern was greatest for the long establishment phase when little

to no harvestable forage is produced (Table 3). Establishment usually requires a year but when

weed control problems occur, successful establishment can take almost two years from the time

of seeding, if establishment occurs at all. This long establishment phase is economically a burden

on producers and according to survey respondents is the main concern producers have for

planting NWSG.

Within establishment reliability, the next most important factor after long establishment phase was

the category, all other factors cited by respondents (Table 3). Concerns listed under the other

category included seed dormancy problems, lack of registered herbicides, poor understanding of

grazing needs, lack of familiarity with NWSG, lack of knowledge of proper planting procedures,

poor knowledge base, inadequate support from Cooperative Extension, low availability of

specialized planters, landowner knowledge, tradition, and lack of ability to burn for maintenance.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

61

Table 1a. Native warm-season grass acreage reported in Eastern United States from November

1999 survey.

Acreage (estimates are for the state

State Species unless otherwise noted)

Range Mean of answers

Switchgrass 100-3,500 2,200

Big bluestem 0-4,000 2,333

Indiangrass 100-1,000 533

Eastern gamagrass 0-500 263

Little bluestem 100-10,000 4,700

Mixtures of above - -

Northeast or New England (VT,

NH, ME, NY)

Other natives 88,000 -

Switchgrass 1 1

Big bluestem 50 50

Indiangrass 0 0

Eastern gamagrass 0 0

Little bluestem - -

Mixtures of above - -

Vermont (State report did not list

acres; acreage is from 2 reporting

counties)

Other natives - -

Switchgrass 35 35

Big bluestem 100 100

Indiangrass 100 100

Eastern gamagrass 1 1

Little bluestem 50 50

Mixtures of above - -

Connecticut

Other natives - -

Switchgrass 1,000 1,000

Big bluestem 100 100

Indiangrass 25 25

Eastern gamagrass 0 0

Little bluestem 5,000 5,000

Mixtures of above - -

Massachusetts

Other natives - -

Switchgrass 300 300

Big bluestem - -

Indiangrass - -

Eastern gamagrass - -

Little bluestem - -

Mixtures of above - -

New Jersey (No state estimate,

reported acres are sum of two

counties reporting)

Other natives - -

Switchgrass 10,000-40,000 25,000

Big bluestem 500-40,000 20,250

Indiangrass 0-10,000 5,000

Eastern gamagrass 0-5,000 2,500

Little bluestem 0-50,000 25,000

Mixtures of above 200 200

Pennsylvania

Other natives - -

Switchgrass 125 125

Big bluestem 275 275

Indiangrass 275 275

Eastern gamagrass 125 125

Little bluestem 75 75

Mixtures of above 2,375 2,375

Delaware (No state estimate,

reported acres are sum of 2

counties reporting)

Other natives - -
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

62

Table 1a. Native warm-season grass acreage reported in Eastern United States from November

1999 survey (Continued).

Acreage (estimates are for the state unless

State Species otherwise noted)

Range Mean of answers

Switchgrass 8-67 (85) 38

Big bluestem 5-41 (41) 23

Indiangrass 0-48 (43) 24

Eastern gamagrass 10-48 (58) 29

Little bluestem 13 (13) 13

Mixtures of above 4562 4562

Maryland (Sum of 6

individual counties in

parenthesis)

Other natives - -

Switchgrass 8,100 (1,776) 8,100

Big bluestem 450 (625) 450

Indiangrass 450 (405) 450

Eastern gamagrass 550 (77) 550

Little bluestem 450 450

Mixtures of above - -

Virginia (Sum of 13

individual counties in

parenthesis)

Other natives - -

Switchgrass 100 (145) -

Big bluestem in mixtures (0) -

Indiangrass 5,000 (native) (0) -

Eastern gamagrass 50 (planted) (0) 100 (native)

Little bluestem - -

Mixtures of above - -

West Virginia (Sum of

7 individual counties

in parenthesis)

Other natives - -

Switchgrass 1,415 -

Big bluestem 1,025 -

Indiangrass 850 -

Eastern gamagrass 10 -

Little bluestem - -

Mixtures of above - -

Ohio (No state

estimate, reported

acres are sum of 4

counties reporting)

Other natives - -

Switchgrass - (6,725) -

Big bluestem - (4,400) -

Indiangrass - (4,400) -

Eastern gamagrass - -

Little bluestem - -

Mixtures of above 60,000 (13,607) -

Wisconsin (Sum of 10

individual counties in

parenthesis)

Other natives (7) -

Switchgrass 5,150 -

Big bluestem 330 -

Indiangrass 85 -

Eastern gamagrass 10 -

Little bluestem 350 -

Mixtures of above 250 -

Michigan (No state

estimate, reported

acres are sum of 9

counties reporting)

Other natives - -

Switchgrass 1,100 -

Big bluestem <150 -

Indiangrass <150 -

Eastern gamagrass <150 -

Little bluestem - -

Mixtures of above 13,650 -

Tennessee (State

estimate)

Other natives - -
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

63

Table 1a. Native warm-season grass acreage reported in Eastern United States from November

1999 survey.

Acreage (estimates are for the state unless

State Species otherwise noted)

Range Mean of answers

Switchgrass 393 -

Big bluestem 29 -

Indiangrass 238 -

Eastern gamagrass 292 -

Little bluestem - -

Mixtures of above - -

Kentucky (No state

estimate, reported

acres are sum of 8

counties reporting)

Other natives - -

Switchgrass 200-1,500 (95) 850

Big bluestem 15-30 42.5

Indiangrass 0-2 1

Eastern gamagrass 0-1,200 (2) 600

Little bluestem - -

Mixtures of above - -

North Carolina (Sum

of 5 individual

counties in

parenthesis)

Other natives - -

Switchgrass 250 -

Big bluestem 0 -

Indiangrass 0 -

Eastern gamagrass 200 -

Little bluestem - -

Mixtures of above 400 -

South Carolina (State

estimate)

Other natives - -

Switchgrass 300 (2,000) -

Big bluestem 50 (50) -

Indiangrass 20 (1,000) -

Eastern gamagrass 100 (200) -

Little bluestem 5,000 -

Mixtures of above - -

Georgia [Estimate for

southeast GA

(250,000 acres) is in

parenthesis]

Other natives - -

Switchgrass 0 -

Big bluestem 7,000 -

Indiangrass 1,000 -

Eastern gamagrass 0 -

Little bluestem 0 -

Mixtures of above 0 -

Florida (No state

estimate, reported

acres are sum of 1

county reporting)

Other natives - -

Switchgrass 300 -

Big bluestem - -

Indiangrass - -

Eastern gamagrass - -

Little bluestem - -

Mixtures of above - -

Alabama (State

estimate)

Other natives - -

Switchgrass 250 -

Big bluestem 0 -

Indiangrass 175 -

Eastern gamagrass 0 -

Little bluestem 200 -

Mixtures of above - -

Mississippi (No state

estimate, reported

acres are sum of 1

county reporting)

Other natives - -
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

64

Table 1a. Native warm-season grass acreage reported in the eastern United States from

November 1999 survey (Continued).

Acreage

State Species Range Mean of answers

Switchgrass - (3,430) -

Big bluestem - (3,180) -

Indiangrass - (2,945) -

Eastern gamagrass - (1,801) -

Little bluestem - (1,000) -

Mixtures of above 176,287 (8,860) -

Missouri (Sum of 8

individual counties in

parenthesis)

Other natives - (1,000) -

Switchgrass <1 (150) -

Big bluestem <1 -

Indiangrass <1 -

Eastern gamagrass <1 -

Little bluestem - -

Mixtures of above - -

Arkansas (Sum of 2

individual counties in

parenthesis)

Other natives - (2,150) -

The next most important category under factors affecting NWSG establishment reliability was

weed control (Table 3). Many NRCS respondents felt that NRCS should take a more active role in

herbicide registration and perhaps act as a third party registrant, if possible. Reliability of

establishment was next most important indicating concern for the success of seedings. Related to

this, seed viability was ranked next and has been reported to be responsible for some failures.

Before planting, growers should always conduct a quick germination test and be certain to plant

at recommended rates using pure live seed (PLS) per acre. The final category, cultivar (variety)

selection, was rated at 4.29 indicating that growers are not concerned about what cultivar they

plant.

After establishment reliability, the next impediment to adoption of NWSG was seed expense and

availability (Table 2). Frequent droughts and adverse weather conditions where seed is produced

have meant that seed supplies and prices fluctuate radically from year to year. Apparently, this

variability in supply and prices has raised serious concerns for many farmers and discouraged

them from planting NWSG.

Managing NWSG in Grazing Systems: The third critical concern was for grazing management

with a rating of 2.41. Two factors plus the ‘other’ category within this were most important to

respondents (Table 4). These were the lack of knowledge about species requirements by

producers and the fact that NWSG sometimes do not fit into the management style of producers.

In the all other factors cited by respondents’ category, comments included the short grazing

season versus the acreage commitment. Many producers do not consider NWSG reliable but to

use them they would have to take some CSG acreage out of production and in return only get at

best a 3-month grazing period. Additional comments included: establishment cost, lack of need

for hay from NWSG in wet seasons, a higher skill level required to manage NWSG, length of

establishment, lack of promotion, the fact that introduced CSG out yield NWSG in some locations,

difficulty in learning a different grazing system, tradition (against their use), and the requirement

of radical change in grazing management if using NWSG.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

65

Table 1b. Native warm-season grass acreage reported in the western United States from

November 1999 survey.

Acreage

State Species Range Mean of answers

Switchgrass 100-525 1,050

Big bluestem 40-140 280

Indiangrass 75-175 350

Eastern gamagrass 50-425 850

Little bluestem -- --

Illinois (No state

estimate, 8 counties

reporting)

Mixtures and natives 390-16,340 32,680

Switchgrass 250-19,000 44,900

Big bluestem 40-10,000 24,090

Indiangrass 20-5,000 9,235

Eastern gamagrass 0-50 205

Little bluestem 0-2,000 4,510

Iowa (No state

estimate, 13

counties reporting)

Mixtures and natives 0-2,000 4,303

Switchgrass -- 14,000

Big bluestem -- 400

Indiangrass -- 100

Eastern gamagrass -- 400

Little bluestem -- --

Nebraska (State

estimate)

Mixtures and natives -- 26,750,000

Switchgrass -- 111,100

Big bluestem -- 25,800

Indiangrass -- 22,330

Eastern gamagrass -- 365

Little bluestem -- 13,400

Nebraska (5

counties reporting)

Mixtures and natives -- 176,700

Switchgrass -- 11,900,00

Big bluestem -- 11,900,000

Indiangrass -- 6,000,000

Eastern gamagrass -- 1,000,000

Little bluestem -- --

Kansas

Mixtures and natives -- --

Switchgrass 1,000-300,000 444,359

Big bluestem 0-300,000 457,425

Indiangrass 0-300,000 471,491

Eastern gamagrass 0-28,131 29,631

Little bluestem 0-400,000 602,527

Oklahoma (No state

estimate, 13

counties reporting)

Mixtures and natives 50,000-130,000 528,385

Switchgrass 50-500 949

Bib bluestem 0-150 155

Indiangrass 0-20,000 21,200

Eastern gamagrass 15-150 215

Little bluestem 0-100,000 100,00

Texas (No state

estimate, only 3

counties reporting)

Mixtures and natives 0-200,000 200,005

Switchgrass 0-8,000 15,750

Big bluestem 0-1,200 2,050

Indiangrass 0-400 800

Eastern gamagrass -- --

Little bluestem -- --

South Dakota (No

state estimate, 7

counties reporting)

Mixtures and natives 1-1,232,500 1,430,500
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

66

Table 1b. Native warm-season grass acreage reported in the western United States from

November 1999 survey (Continued).

Acreage

State Species Range Mean of answers

Switchgrass -- 40

Big bluestem -- --

Indiangrass -- --

Eastern gamagrass -- --

Little bluestem -- --

Louisiana (No state

estimate, 1 county

reporting)

Mixtures and natives -- --

Switchgrass -- 6,000

Big bluestem -- 200

Indiangrass -- 20

Eastern gamagrass -- --

Little bluestem -- --

North Dakota (No

state estimate, 1

county reporting)

Mixtures and natives -- 50

Switchgrass -- --

Big bluestem -- 1,500

Indiangrass -- --

Eastern gamagrass -- --

Little bluestem -- 200,000

Montana (No state

estimate, 1 county

reporting)

Mixtures and natives -- 795,000

Switchgrass -- --

Big bluestem -- --

Indiangrass -- --

Eastern gamagrass -- --

Little bluestem -- --

Washington (No

state estimate, 1

county reporting)

Mixtures and natives 150,000-200,000 175,000

Switchgrass - 150

Big bluestem -- --

Indiangrass -- --

Eastern gamagrass -- --

Little bluestem -- --

Idaho (State est.)

Mixtures and natives -- 10,000

Switchgrass -- --

Big bluestem -- --

Indiangrass -- --

Eastern gamagrass -- --

Little bluestem -- --

Other western

states1

Mixtures and natives -- --

1

 Reliable data were not available for Minnesota and California; no acreage was reported in

Arizona, Wyoming, Oregon, Colorado, and Utah; All remaining states did not respond to the

survey.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

67

Table 2. Rankings from 1 (most important) to 5 (least important) of factors limiting the adoption of

native warm-season grasses (NWSG) in the Eastern vs. Western U.S.

Rating

Factor Eastern U.S. Western U.S.

Establishment reliability 1.63 2.11

Seed expense and/or availability 2.16 1.92

Knowledge of grazing management techniques 2.49 2.57

Perception of lower forage quality of NWSG vs. coolseason grasses2.88 3.11

Knowledge of hay management techniques 3.41 3.67

Intake limitations 4.15 3.86

Table 3. Rankings from 1 (most important) to 5 (least important) of factors limiting the

establishment reliability of native warm-season grasses (NWSG) in the Eastern vs. Western U.S.

Rating

Factor affecting establishment reliability of NWSG Eastern U.S. Western U.S.

Long establishment phase 1.91 1.82

All other factors cited by respondents 2.08 1.88

Weed control 2.32 2.43

Reliability 2.62 3.05

Seed viability 2.93 3.43

Cultivar (variety) selection 4.29 4.07

Table 4. Rankings from (most important) to 5 (least important) of factors affecting grazing

management of native warm-season grasses (NWSG) in the Eastern vs. Western U.S.

Rating Factors affecting grazing management of NWSG Eastern U.S. Western U.S.

All other factors cited by respondents 1.30 1.33

Lack of knowledge of species requirements 2.12 1.93

Does not fit manager’s grazing style 2.14 2.31

Weed control 2.92 3.13

Palatability concerns 3.09 2.88

Concerns over the use of controlled burns 3.13 3.59

Expected gain per acre 3.29 3.00

Expected gain per animal unit 3.30 2.85

Cultivar (variety) selection 3.85 4.27

Toxicity concerns (photosensitivity in sheep during years of

drought and heat stress with switchgrass)

4.38 4.47

Other factors that were moderately important were weed control (lack of), palatability concerns,

problems of understanding and using controlled burns to manage the grasses, expected livestock

gain per acre, and expected weight gain per animal unit (Table 4). Least important in managing

NWSG for grazing were cultivar selection and concerns over toxicity (see section below).

Managing NWSG for Hay: Hay management was a concern but was not as much of an

impediment to adoption of NWSG as was grazing management (Table 2). Within hay

management, the all other factors cited by respondents’ category again ranked first in importance

(Table 5). Comments this category involved forage quality and market value, yield—quality

versus quantity, obtaining only one good cutting, lack of promotion, lack of knowledge of nutrient

content of NWSG, and lack of specific information on hay management for NWSG.

Table 5. Rankings from 1 (most important) to 5 (least important) of factors affecting hay

management of native warm-season grasses (NWSG) in the Eastern vs. Western U.S.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

68

Rating

Factors affecting hay management of NWSG Eastern U.S. Western U.S.

All other factors cited by respondents 1.60 1.00

Long establishment phase 1.67 1.82

Reliability of establishment 2.53 2.97

Weed control 2.57 2.97

Seed viability 3.18 3.97

Cultivar (variety) selection 3.90 3.63

The long establishment phase when no hay is produced was a major concern for growers. Weed

control and reliability of establishment were also important factors inhibiting the adoption of

NWSG for hay. Seed viability was another issue since it has a significant impact along with the

long establishment phase on the economics of planting NWSG for hay.

Factors to Promote NWSG: Survey respondents were asked to rank a number of factors that

could promote more use of NWSG in the Eastern U.S. The most important factor was the

production of forage during the summer months when heat and moisture stress can severely limit

the productivity of the CSG (Table 6). Next in importance was the improved drought tolerance of

the NWSG as compared to the introduced CSG. Reed canarygrass has shown some tolerance to

drought conditions. Recent breeding improvements in reducing alkaloid content and improving

palatability have increased the appeal of this grass to forage producers.

Two other factors important in promoting NWSG are potential wildlife benefits both in regard to

forage potential and nesting cover and the potential to produce high tonnage and excellent weight

gains when grazed properly or cut for hay at the correct growth stage (Table 6). Concentrating

hay production in the summer months when it is easier to cure the hay was also considered

important. Lower nitrogen requirements can decrease production costs after successful

establishment and promote the use of these crops where nutrient management concerns are

high. The lowest rated category was the use of NWSG and switchgrass in particular as a biomass

or biofuel crop. Although important in a few states, for most other states biomass/biofuel was

rated lowest in importance.

Table 6. Rankings from 1 (most important) to 5 (least important) of factors that will promote more

use of native warm-season grasses (NWSG) in the Eastern United States.

Rating Factors promoting more use of NWSG Eastern

U.S.

Western

U.S.

Forage production during the summer months 1.70 2.00

Better drought tolerance or water use efficiency by NWSG 2.21 2.24

Potential tonnage and improved weight gain when used best 2.63 2.36

Wildlife benefits 2.63 2.74

Hay production concentrated in summer months when it can be

more easily cured

2.98 3.22

Lower fertilizer requirements compared to cool-season grasses 3.13 2.73

Biomass/Biofuel potential 4.14 3.82

All other factors cited by respondents 1.15 1.67

Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

70

Table 7. Native warm-season grasses (NWSG) use in the Eastern United States according to 1999 survey either by state eaveraging acreage reports from individual counties responding to the survey.

Percentage of Land Area by Usage Category

State(s)

Grazed

land

Hay

land

% Cut

for cow

/calf

% Cut

for beef

% Cut

for

sheep

% Cut

for

goat

% Cut

for

other

*

Wildlife

habitat

**

Wildlife

feed

Land

Conservation

/Protection

CREP/

CRP/

WHIP

Northeast/New England(VT, NH, ME, and NY) 0 20 100 -- -- -- -- 30 -- 50 -- Vermont 1 1 100 -- -- -- -- 50 24 24 -- Connecticut 0 0 -- -- -- -- -- 75

***

25 50 -- 

Massachusetts 0 0 -- -- -- -- -- 50 -- 50 -- New Jersey 0 0 -- -- -- -- -- 50 -- 50 -- Pennsylvania (State est.) 17.3 15.2 72.4 27.6 -- -- -- 32.9 13.3 22.7 -- Pennsylvania (County) 5.0 5.6 100 -- -- -- -- 89.4 62.5 -- -- Delaware 1 0 80 20 -- -- -- 95 85 15 -- Maryland (State est.Ψ) 0.5 1.5 20 80 -- -- -- 98 -- -- 99.5 Maryland (County avg.) 2 34.5 25.2 67.2 -- 3.1 4.5 61.2 -- -- 18.5 Virginia 21 9 80 20 -- -- -- 40 -- 30 -- West Virginia 45 5 90 5 3 2 -- 50 -- -- -- Ohio 0 46 2ΨΨ 0.2 -- -- -- 96 1.4 7.3 -- Wisconsin (State est.) 1 2 99 -- -- -- -- 20 -- 76 100 Wisconsin (County avg.) 0.24 0.48 99 -- -- -- 1 74 64.4 29.3 -- Michigan 0 0.7 -- 100 -- -- -- 90.6 6.3 11.3 -- Tennessee 4 1 -- -- -- -- -- 95 -- -- -- Kentucky 3.8 4.2 -- 100 -- -- -- 91.7 40.7 76.9 72.5 North Carolina 12.3 31.7 38 62 -- -- -- 52.6 2.4 1 -- South Carolina 45 30 100 -- -- -- -- 20 -- 5 -- Georgia (State estimate) 0 100 -- -- -- -- -- -- -- 10 -- Georgia (Southeast GA) 10 10 90 -- -- -- -- 80 -- -- -- Florida 0 95 95 5 -- -- -- 5 -- -- -- Alabama 0 0 -- -- -- -- -- 0 0 0 -- Mississippi 0 0 -- -- -- -- -- -- -- 100 -- Missouri 20.5 17.5 75.6 13.1 -- -- 0.6 30 -- 50.5 100 Arkansas (State est.) 15 15 50 50 -- -- -- 70 -- -- -- Arkansas (County est.) 100 100Ω 80 20 -- -- -- -- -- -- -- • Other grazing animals were horses and dairy cows. 

**

 Wildlife mentioned were white tailed deer, turkey, bob white quai

pheasant, upland song birds, ducks, geese, and rabbits. 

***

 Totals add up to more than 100 percent since multiple uses 

Ψ Ninety-eight percent of grazed and hayed NWSG area was not specified according to species use. ΨΨ Est. = estimateSpring/summer harvest cut for hay and fall growth grazed so both 100 percent.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

71

Table 8. Native warm-season grasses (NWSG) in the Western United States uses according to 1999 survey either by state averaging acreage reports from individual counties responding to the survey.

Percentage of Land Area by Usage Category

State(s)

Grazed

land

Hay

land

% Cut

for

cow/calf

% Cut

for

beef

% Cut

for

sheep

% Cut

for

goats

%

Cut

for

other

*

Wildlife

habitat

(WLH)

**

Wildlife

feed

Land

Conservation/

Protection

Illinois (8 County est.Ψ) 0.85 0 100 -- -- -- -- 93.2 2.6 95.1*** Illinois (26NW Countyest.)

15 5 45 25 -- -- -- 80 -- In WLH 

Iowa (12 County est.) 3.3 16 87.7 10.85 1.45 -- -- 59.7 1.4 49.1 Nebraska (State est.) 90 10 70 12 1 -- 4 3 -- 5 Nebraska (5 County est.) 58.7 33.5 68.4 24.4 1.3 -- 0.4 2.7 48.6 25.7 Kansas (State est.) 85 15 50 50 -- -- -- -- -- -- Kansas (1 County est.) 90 10 74 18.5 7 0.2 0.2 0.1 -- 2.8 Oklahoma (13 Countyest.)

77.3 20.6 57.7 18.0 2.0 1.54 0.65 15.5 5.4 7.1 

Texas 99.99 .001 76.3 17.1 3.6 2.3 0.63 99.97 34.2 34.2 South Dakota (7 Countyest.)

90.6 6.7 80.8 4.6 8.7 .006 4.3 0.9 2.6 3.9 

Louisiana (1 County) -- -- -- -- -- -- -- -- -- 100 North Dakota (1 County) 80 20 50 50 -- -- -- 80 -- 100 Montana (1 County est.) 98 2 75 20 5 -- -- 100 100 -- Idaho (State est.) 75 5 50 40 10 -- -- 100 -- 20 Washington (State est.) 50 10 80 15 -- -- -- 25 -- 38 Colorado (1 County est.) -- -- -- -- -- -- -- -- -- 100 California (2 County est.) -- -- -- -- -- -- -- 30 -- 30ΨΨ *

 Other foragers included horses, bison, and dairy cows. 

**

 Wildlife reported to benefit from NWSG include white tailed deer

turkey, Rio Grande turkey, bob white quail, sharp tailed grouse, ringneck pheasant, ducks, geese, waterfowl, whooping cracranes, jackrabbit, antelope, elk, and upland game birds. 

***

 Totals add up to more than 100 percent since multiple uses we

Est. = estimate. ΨΨ Natural land restoration was an additional 40 percent. ΨΨΨ Iowa counties also reported seed production 

of acres.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

72

The category (all other factors cited by respondents) contained several interesting ideas for

promoting NWSG. Additional accessible test and evaluation plots, more information on seeding

and establishment, lower seed costs, improved establishment techniques, EPA-approved

herbicides to assist in establishment, and demonstrations of summer grazing would help promote

the crop. Promotion of these crops by NRCS and Cooperative Extension through the

Conservation Reserve Program (CRP) requirements, erosion control programs, and other

government programs can be effective in increasing the use of NWSG. Improved communication

with producers to increase their knowledge of the value of these crops in grower production

systems can increase the use of NWSG.

NWSG Uses

Wildlife habitat and/or feed and land protection/conservation purposes were the primary use of

the majority of acres in NWSG according to the survey (Table 7). Probably only one-third of the

acres in NWSG is used primarily for hay and grazing. Overall, in the eastern states, while usage

varied widely from state to state, most of the acreage is used for hay or grazing. Cow-calf and

beef operations constituted the majority of forage users.

However for the western states, usage again varied widely from state to state (Table 8) although

grazing accounted for 75 to almost 100 percent of the NWSG usage. Within the acres grazed or

hayed, the vast majority was for cow-calf operations, a smaller percentage (usually about 25

percent) for beef, and much of the remaining 1 to 10 percent for sheep. Many states used NWSG

as a dual-purpose cover for wildlife habitat and land conservation and protection. Nebraska and

Texas reported the largest acreage percentage for biomass-biofuel use.

Literature Review

Establishment

Cultivar selection is an important aspect of establishment. However, cultivar suitability varies

widely from location to location and environment to environment. To choose an appropriate

cultivar, contact local seed dealers, Cooperative Extension, University research facility, or other

company or agency that will have information pertinent to local conditions. Wolf and Fiske (1995)

reported that if switchgrass is to be grazed the preferable cultivar was Indian.

Establishment of perennial grasses can be divided into two separate phases. The first phase

involves seed imbibition of water, enzyme activation, seed germination, and seedling emergence.

The second phase is the development of the adventitious root system (Newman and Moser

1988). In general, establishment failures most often are caused by inadequate soil moisture,

weed competition, low seedling vigor, or poor germination. Research has shown that within a

species, larger, heavier seeds have a higher germination rate (Kneebone 1972; Kneebone and

Cremer 1955; Rogler 1954; and Tossell 1960) and these seedlings have more rapid growth after

emergence (Kneebone and Cremer 1955; Tossell 1960; Trupp and Carlson 1967) than those

from lighter seed. This has been shown to be true for switchgrass (Aiken and Springer 1995;

Green and Bransby 1995).

Smart and Moser (1999) found that seed size differences in switchgrass appeared to produce

only slight differences in morphological development of shoot and root systems, leaf area, shoot

weight, and adventitious root weight from seedling emergence through six weeks of growth.

Adventitious roots formed more quickly on seedlings from heavier than lighter seed, but the

advantage to seedling establishment was minimal even under moisture stress. After seedlings

had formed two or more adventitious roots, seed size no longer affected establishment and

growth. Smart and Moser (1999) concluded that seed size in switchgrass appears to have a

minimal long-term effect on growth and development of seedlings. However, formation of

adventitious roots is critical to seedling survival (Hyder et al. 1971; Newman and Moser 1988;

Ries and Svejcar 1991) and depends primarily on the presence of adequate soil moisture in the

surface layer (Newman and Moser 1988; Wilson and Briske 1979).

Roundy et al. (1993) found that for the three warm-season grasses (WSG) studied including sideoats grama [Bouteloua curtipendula (Michx.) Torr.] seminal root elongation rates ranged from

0.229 to 0.343 inches d-1 (5.8 to 8.7 mm d-1). If the typical drying front in the soil during the period
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

73

of establishment moves faster than seminal (adventitious) root growth, frequent rainfall will be

needed to permit adventitious root development and establishment of warm-season grasses. Of

the species Roundy et al. (1993) studied, all three grasses elongated their subcoleoptile

internodes to place the coleoptilar node and site of adventitious root initiation near the soil surface

regardless of seeding depth.

Problems with switchgrass establishment from seed seem to be related to inherent seed

dormancy from seeds harvested in fall and seeded the following spring (Blake 1935; Robocker et

al. 1953). Although storing seed for a year or two to overcome dormancy problems (Byers 1973;

Robocker et al. 1953; Shaidaee et al. 1969) seems to be the obvious answer, economics and

frequent seed shortages prevent the implementation of this solution. Zarnstorff et al. (1994) found

that wet pre-chill treatment significantly increased germination percentage. They also found some

increase from treatment with ethylene and gibberellin although the increases were small. They

concluded that post-harvest storage of seeds at 73° F (23° C) from January to April (90 days)

should ensure adequate germination at time of seeding.

Beckman et al. (1993) evaluated seed priming as an option for improving establishment in big

bluestem and switchgrass. Seed priming is an osmotic conditioning process in which seed is

hydrated to a level that pre-germination metabolic activity is initiated but emergence of the radicle

does not occur (Bradford 1986). A form of this is called solid matrix priming (SMP). SMP is a

process in which seed is mixed with a particulate solid matrix material and provided aeration and

only enough water to allow osmoconditioning, but not germination (Eastin 1990). Beckman et al.

(1993) found that in field studies, SMP-treated seed produced the highest seedling emergence for

switchgrass under moist planting conditions and had the potential to improve stands when seed

was planted without drying. However, final seedling emergence from dry untreated seed was

greater than that for SMP-treated seed under dry soil conditions which occur more frequently than

wet soil conditions during traditional switchgrass planting times.

Seeding Rate and Placement

Masters (1997) found that for big bluestem frequency of success during planting increased as

seeding rates increased from 10.2 to 20.4 to 40.9 pure live seed (PLS) ft-2 (110 to 220 to 440 PLS

m-2). Within this range, Anderson (1989) recommended a seeding rate of at least 31 PLS ft-2 (8.3

lb. PLS A-1) [330 PLS m-2 (9.3 kg PLS ha-1)] to establish big bluestem in monoculture stands. Wolf

and Fiske (1995) recommend in Virginia and North Carolina a seeding rate for switchgrass of 10

lb. PLS A-1 (11.2 kg PLS ha-1) for conventional plantings and 8 lb. PLS A-1 (8.96 kg PLS ha-1) for

no-till plantings. They noted differences in cultivars for seeds per pound with Indian switchgrass

having usually 250,000 seed lb-1 (551,250 seed kg-1) versus Alamo with 454,000 seed lb-1

(1,001,070 seed kg-1). Wolf and Fiske (1995) recommend a “Ragdoll” test for germination that

can easily be done by producers. Seed tests often indicate very high germination since the test is

done under ideal conditions that include stratification. For later plantings, stratification will not

occur in the field and the “Ragdoll” test will provide a better estimate of PLS.

Seed placement in rows with a grain drill that has a small seed or fluffy seed attachment (for seed

like big bluestem, Indiangrass, and little bluestem) is ideal. When seeding in a conventional

seedbed be sure it is weed-free and that the soil is especially firm at planting. Cultipacking after

drill planting to obtain good soil-seed contact is desirable. No-till plantings should not be made

when the soil surface is too wet or else the seed will be planted too deep. Place seed 1⁄4 to 1⁄2 inch

deep. After emergence observe the planting for signs of insect damage. If grassy weeds become

a problem, their competition can be minimized by clipping above the height of the leaves of the

NWSG seedlings.

Planting Date

Smart and Moser (1997) suggested using earlier planting as a means of avoiding planting failures

from dry soil conditions and annual grass and broadleaf weed competition. This could result in

better adventitious root formation important for seedling survival. Another benefit suggested is a

reduction in seed dormancy that results from exposing seed to cool moist conditions in the

seedbed. However, seedlings resulting from early spring seeding in the northeast and midAtlantic regions may be impacted by late-season frosts.
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74

Smart and Moser (1997) found that seedlings from March planting dates were more advanced

morphologically in both root and shoot development, had accumulated 2 to 12 times more leaf

area, 2 to 10 times more shoot mass, and 2 to 33 times more adventitious root mass than

seedlings from April or May planting dates.

Wolf and Fiske (1995) report that switchgrass germinates very slowly when soil temperature is

below 60°F (16°C); but, if maintained at 85°F (30°C) for three days, many seeds will germinate.

Therefore, they suggest a planting time similar to that for millet [Pennisetum spp.] and sorghumsudangrass [Sorghum drummondii (Nees ex Steud.) Millsp. & Chase]. For conventional seedings,

they suggest planting between June 1 to 15 since soil moisture may become limited when

planting later than June 15. For no-till, they suggest planting between June 15 and July 15 since

soil moisture is usually less of a concern; earlier planting is possible in situations where weeds

are not a problem. Later planting limits weed competition helps weed control. Seedlings should

develop tillers before the fall to ensure winter survival.

Weed Control

Developing productive stands of NWSG is difficult when compared to CSG in part because

NWSG are slow to establish dense ground cover (Panciera and Jung 1984; Warnes et al. 1971;

Robocker et al. 1953). This characteristic makes the NWSG vulnerable to weed competition in

the seedling year. Herbicides once available for use during establishment are no longer

registered for use on these grasses.

There is a wide tolerance for the herbicide atrazine among WSG (Martin et al. 1982), and

switchgrass and big bluestem were two of the most tolerant species. Bahler et al. (1984) reported

that atrazine reduced stands of switchgrass and Caucasian bluestem [Bothriochloa caucasica

(Trin.) C. E. Hubbard] in a loamy sand (Udic Haplustoll) more than in a silty clay loam (Typic

Argiudoll). McKenna et al. (1991) found that atrazine at 2 lb. a.i. A-1 (2.2 kg a.i. ha-1) appeared to

injure switchgrass more than Caucasian bluestem. They found that dry matter yields in the

second year confirmed their impression. They concluded that atrazine at 1 lb. a.i. A-1 (1.1 kg a.i.

ha-1) was considered the best recommendation for the establishment of the two species. Martin et

al. (1982) found that preemergence applications of atrazine caused less stand reduction in

switchgrass and big bluestem than in Indiangrass and side-oats grama. Increasing the rate of

atrazine decreased seedling height and seedling number (Bahler et al. 1984; Martin et al. 1982;

Bovey and Hussey 1991). McKenna et al. (1991) also found that the insecticide, carbofuran, at 1

lb. a.i. A-1 (1.1 kg a.i. ha-1) placed in the row with the seed at planting enabled seedlings to

develop faster, elongate more rapidly, and produce heavier and more seedlings than without

carbofuran.

Weed competition in young stands of NWSG can inhibit grass seedling vigor and establishment.

Warm-season grass yields can be as low as 1,116lb A-1 (1,250 kg ha-1) or even undetectable

during the establishment year without any form of weed control (Martin et al. 1982; Masters et al.

1990). Atrazine can significantly increase establishment year yields for switchgrass [7,519 lb. A-1

(8,420 kg ha-1)] and big bluestem [3,840 lb. A-1 (4,300 kg ha-1)] (Martin et al. 1982).

Masters (1997) found that metolachlor (Dual) and/or atrazine could be applied preemergence the

year of planting to improve yield of big bluestem seeded as low as 10.2 PLS ft-2 (110 PLS m-2).

Metolachlor provided better control of warm-season annual grasses than atrazine including large

crabgrass [Digitaria sanguinalis (L.) Scop.], fall panicum [Panicum dichotomiflorum Michx.], green

and yellow foxtails [Setaria spp.], and barnyardgrass [Echinochloa crus-galli (L.) P. Beauv.].

Masters (1995) found that metolachlor was a suitable replacement for atrazine to improve

establishment of big bluestem and sand bluestem cultivars although yield and stand frequency

were maximized when metolachlor and atrazine were applied in combination. Weed control

provided by metolachlor and atrazine could reduce both the cost of big bluestem establishment

through lower seeding rates and the risk of seeding failures. The use of metolachlor and atrazine

has potential to be cost effective by ensuring increased seeding success and lower seeding rate

necessary for big bluestem establishment

However, weed control is now more difficult to attain, because switchgrass and big bluestem

pastures for forage production have been removed from the atrazine label. This can substantially
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increase producers cost since greater weed competition can result in little biomass production for

grazing or hay during the establishment year and this means the land must be left idle for a year

or more. Hintz et al. (1998) evaluated the establishment of switchgrass and big bluestem in corn

[Zea mays L.] using atrazine. They found that the use of corn as a companion crop could provide

potential for high biomass production during NWSG establishment by allowing the use of atrazine

for weed control. They found that both switchgrass and big bluestem successfully established in

corn and that long-season corn hybrids and higher density corn populations increased corn silage

or grain yield without reducing NWSG stands. They concluded that switchgrass and big bluestem

grown in corn with atrazine reduced land production losses during the establishment year, yet

allowed adequate establishment of these grasses for future forage production.

As noted in a survey of NRCS personnel and forage agronomists, weed control is essential for

NWSG establishment. More effort must be made to obtain registration of herbicides to control

annual grass and broadleaf weeds during the establishment year. Work along the lines of Hintz et

al. (1998) offers options to producers but all workers involved in promotion of NWSG need to

explore ways to obtain registration of herbicides for these grasses or other options to permit the

legal use of herbicides during establishment.

Yield Potential of NWSG

Yield estimates for NWSG vary widely depending on the management regime; fertilization

practices; age of stand; climate factors such as temperature, rainfall, and accumulated solar

radiation; cultivar; height of cut; and a host of other factors. Papers to review on this topic include

Belesky and Fedders (1995), Berg (1971), Faix and Kaiser (1982), Faix et al. (1977), George et

al. (1990), Henry et al. (1976), Jung et al. (1985), Reid et al. (1988a), and Stout et al. (1986).

Fertility for NWSG

NWSG in the Midwest have yielded well on phosphorus (P) deficient soils (Daniel and Harper

1934; Murphy 1933) and were shown to respond to P fertilizer with increased yields and higher

forage P concentrations (Fraps and Fudge 1945; McMurphy et al. 1975; Murphy 1933; Taliaferro

et al. 1975). Morris et al. (1982) found that CSG absorbed markedly more P than the WSG at low

and high P fertilization rates although the trend did not hold every year. For both types of grasses,

the P uptake response was about 80 to 100 percent higher on the P fertilized soil each year of

their study. P uptake varied significantly among WSG cultivars. Morris et al. (1982) reported that

weed competition was a factor affecting grasses at high not low P levels. The WSG studied

produced high yields on both the low and high P soils. They suggested that the NWSG have

tolerance and adaptation to lower levels of available P resulting in little yield increase with P

fertilization.

Nitrogen (N) fertilization plays an important management role for boosting forage production on

NWSG swards (Perry and Baltensperger 1979; Hall et al. 1982). Environment also plays an

important role in the response of NWSG to N fertilization since it affects the release and

transformation of N components in the soil and the efficiency of NWSG in using N (Craswell and

Godwin 1984). Rainfall amount, rainfall distribution pattern, temperature, and solar intensity all

impact the interdependent soil—microorganism—plant system. Stout and Jung (1995) reported

that the less fertile the soil the greater the increase in switchgrass yields and with increasing rates

of N the greater the accumulation of N in the tissues. Nitrogen fertilization increases the crude

protein concentration in NWSG (Chapman and Kretschmer 1964; Cuomo and Anderson 1996;

Dee and Box 1967; Madakadze et al. 1999; Minson 1973; Rehm 1984, Rehm et al. 1977).

Cuomo and Anderson (1996) found that 65 percent of the additional crude protein (CP)

associated with N fertilization was rumen degradable protein (RDP). They found that RDP was

greater in switchgrass and Indiangrass than in big bluestem.

Perry and Baltensperger (1979) found that N fertilization increased leaf CP percentages and leaf

yields of big bluestem, Indiangrass, and switchgrass especially for later harvests. Leaf material of

all grasses comprised approximately 85 percent of the total forage yield at most N levels. Rapid

declines occurred in leaf CP and in vitro digestible dry matter (IVDDM) throughout the growing

season, indicating that leaf maturation was responsible for declining forage quality rather than

stem growth in these NWSG. However, McMurphy et al. (1975) found that severe lodging of big
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bluestem at 160 lb. A-1 (180 kg N ha-1) limited its yield potential. Fertilizer N recovery for NWSG

was most efficient (52 to 66 percent) at 80 lb N A-1 (90 kg N ha-1) plus 35.7 lb P A-1 (40 kg P ha-1)

[82 lb. P2O5 A-1 (91.8 kg P2O5 ha-1)] (McMurphy et al. 1975).

Jung et al. (1990) also studied the response of NWSG yield, plant morphology, and forage N

composition in a long-term study. The percentage showing a yield response to applied N of

grasses from six genera of WSG grown in Pennsylvania increased each year although the mean

yield response to N varied greatly among cultivars. The sheath-stem component of dry matter

yield was 6 percent (60 g kg-1) higher when N was applied than when no N was applied. Jung et

al. (1988) found that N fertilization increased the production of stems and leaf sheaths more than

leaf laminae.

Balasko and Smith (1971) found that total nonstructural carbohydrate percentages in switchgrass

herbage, stubble, and rhizomes at anthesis were not affected greatly by temperatures or N rate.

Nitrogen fertilization generally increased nutrient element concentrations.

Brown (1985) reported that dry matter produced per unit of N absorbed was twice as high in C4

grasses as in other species (C3 and C3 /C4). He concluded that at very low soil N levels, C4

species are likely to produce more growth and be more competitive than C3 species. NWSG (C4)

use soil nutrients more efficiently and have lower macronutrient requirements than CSG (C3)

(Kroth and Mattas 1982; Morris et al. 1982; Wuenscher and Gerloff 1971).

For switchgrass, Friedrich et al. (1977) found that dry matter yield of all herbage fractions

increased significantly with each increment of N [0, 200, and 400 lb N A-1 (0, 224, and 448 kg N

ha-1) as ammonium nitrate in split applications]. At the highest rate of N, fertilizing with sulfur (S)

increased N concentration in the leaves, decreased N concentration in the stems, and increased

the total herbage uptake of N. When S was applied, switchgrass responded to increased N

fertilization by increasing S uptake. Critical N:S ratios for switchgrass appeared to be greater than

10:1 for herbage, greater than 12:1 for leaf blades, and greater than 8:1 for stems.

Staley et al. (1991) found that on acidic soils of varying water holding capacity (WHC) first cut

switchgrass yields were two- to three-fold greater than for tall fescue (mid-June cut) on all sites

receiving N. Second cuttings were similar between species but much reduced. Nitrogen

concentration generally increased with N rate but not with WHC. Percentage of total N uptake

derived from fertilizer N ranged from 23 to 47 percent for tall fescue and 14 to 39 percent for

switchgrass. Switchgrass took up 25 to 33 percent of the fertilizer N applied to the two deeper soil

sites. At one shallow soil site at the 80 lb N A-1 (90 kg N ha-1) level, switchgrass took up 31

percent compared to tall fescue at 19 percent. They concluded that despite relatively low uptake

rates by both species, switchgrass used fertilizer N more efficiently (yield and uptake) and,

therefore, recommended usage in the Appalachian Region of the Eastern United States where N

rates are low.

Stout and Jung (1995) found in a 3-year 4-site study on switchgrass that soil N, N fertilization,

and temperature controlled biomass accumulation rates. Total N uptake rates ranged from 1.33 to

2.35 lb A-1 d-1 (1.49 to 2.63 kg ha-1 d-1) and were controlled by soil N levels and N fertilization.

Fertilizer N uptake averaged about 40 percent and was lowest where yearly soil N mineralization

exceeded 2,000 ppm (2.0 g kg-1).

Soil fertility is more critical for NWSG at planting time. Growers are often tempted to emulate the

fertilization requirements for introduced CSG by applying 25 to 50 lb A-1 (28 to 56 kg N ha-1) at

planting. Nitrogen should not be applied at or shortly after planting since under low soil N levels

the NWSG often out-compete weeds for water and nutrients (Capel 1977). Judicious applications

of N may be made to assist growth once establishment is successful if forage is needed later

during the establishment year and weeds are not a serious concern. The application should be

kept below 50 lb N A-1 (56 kg N ha-1). Weed growth is minimized when N application is delayed

until right after the first cutting where hay production includes two cuttings per year (Rehm et al.

1976).
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77

Eastern gamagrass requires different management practices than other NWSG (Aiken and

Springer 1998). It tolerates more frequent harvesting and requires higher rates of N and more

frequent applications of N. Brejda et al. (1997) found that variations in precipitation amounts

influenced harvest yields of eastern gamagrass regrowth cuttings. They also noted that the

grass’s response to N rate varied between years. Peterson et al. (1999) found that eastern

gamagrass was highly responsive to N rates up to 150 lb N A-1 yr-1 (168 kg N ha-1 yr-1) and that N

fertilization increased CP concentrations as well as acid detergent fiber and neutral detergent

fiber concentrations.

For all NWSG prior to planting, soil pH should be adjusted to the upper 5’s or higher and

phosphorus and potassium soil test levels should be brought to the medium soil test level. For

calcium, magnesium, sulfur, and the micronutrients, follow soil test guidelines for other grass

forage crops.

Brejda et al. (1998) found that switchgrass seedlings inoculated with rhizosphere microflora

produced up to 15-fold greater shoot and root yields and recovered up to 6-fold more N and 36-

fold more P than seedlings inoculated with rhizosphere bacteria only. Rhizosphere populations

that stimulated the greatest N uptake differed from populations that resulted in the greatest P

uptake. These effects were thought to be mainly due to arbuscular mycorrhizal fungi. Future

developments in this field may allow manipulation of NWSG nutrient uptake and performance on

poor sites.

Interseeding Legumes for Yield and Quality

Mixed stands of NWSG, CSG, and legumes can be maintained under grazing and hay

management systems although grazing management and species selection must be oriented to

favor NWSG persistence. Jung et al. (1985) found that the mean yield distribution of switchgrass

and bluestem pastures was approximately 15 percent in May, 55 percent in July to August, and

30 percent in October. Fertilization of NWSG with 40 to 80 lb N A-1 (45 or 90 kg N ha-1) increased

crude protein concentration by 10 to 26 percent, respectively, versus unfertilized grass. Jung et

al. (1985) also found that legumes, especially red clover [Trifolium pratense L.], can establish

good stands in NWSG and that legumes can be maintained under grazing or hay production, with

a substantial shift in seasonal yield distribution that can be very beneficial to beef producers.

A number of researchers have looked at various legumes for interseeding into NWSG. Legumes

grown in combination with grasses can provide symbiotic N to the associated grass (Farnham

and George 1993; Mallarino et al. 1990; Evers 1985). Gettle et al. (1996b) concluded that yields

of legume-renovated switchgrass were generally greater than for mid to high levels of N

fertilization during the second year following frost seedings of a number of legumes. With legume

frost seedings, Gettle et al. (1996b) suggests that producers limit the acreage seeded to only part

of the existing switchgrass pasture so that the remaining acreage can be fertilized with N to

maintain high forage supply and pasture productivity. Frost seeded legumes, which involves

broadcasting legume seed in late winter or early spring when daily freezing and thawing cycles

work small legume seeds into the soil, can replace from 60 to 120 lbs. N A-1 (67.2 to 14.4 kg N

ha-1) and will involve the least cost for establishment.

Gettle et al. (1996a) found that frost-seeded legumes did not seriously reduce switchgrass stem

density, although red clover, birdsfoot trefoil [Lotus corniculatus L.], and their mixture were more

competitive than other legumes tested. With proper attention to the recommended steps for frost

seeding, legumes can be successfully introduced into established Indian switchgrass and will

persist for several years with favorable weather. Similar results were obtained by Blanchet et al.

(1995) for no-till interseeding of legumes into established switchgrass swards.

A number of researchers have found that cool-season legumes can substitute for N fertilization

after the seeding year (McGinnies and Townsend 1983; Jung et al. 1985; Posler et al. 1993;

George et al. 1995; Gettle et al. 1996a,b). To maintain warm-season grass productivity, legume

competition should be minimized by adequate defoliation by early June.
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78

Grazing NWSG

Perennial NWSG have been found to be some of the most productive grasses available for

production of summer grazing in many areas of the Eastern U. S. They often grow well on acidic

soil and are efficient in the use of water and plant nutrients (Stout et al. 1986; Staley et al. 1991).

However, they are C4 grasses and have high levels of structural fiber and low concentrations of N

and certain essential elements especially at or near maturity (Reid et al. 1988 a,b). Certainly in

relation to the non-native, CSG, estimates of digestibility, both in vitro and in vivo, have been

relatively low. However, grazing studies, in contrast, have shown good animal performance

(Burns et al. 1984; Anderson et al. 1988). Vona et al. (1984) and Reid et al. (1988b) reported

higher levels of intake by cattle than would have been predicted from fiber concentrations and

digestibility values.

A number of factors affect animal performance on these grasses and include but are not limited to

the management system employed, the stage of growth at which grazing is initiated, leaf to stem

ratio, stocking rate and grazing selectivity, and fertilization of the grasses.

Wolf and Fiske (1995) report that each acre should provide about 200 animal unit days (AUD) of

grazing per year (switchgrass). To maximize yields, rotational grazing is required. Intensive

grazing, a form of rotational grazing, is best to use with the NWSG since it will allow better control

over the height of stubble remaining after the grazing period and stubble height is critical to

maintaining NWSG stands. Work in Pennsylvania indicated that by grazing early and at high

densities 12 AU A-1 (30 AU ha-1) animal gains can approach 3 lb. day-1 (1.36 kg day-1). Similar

gains have been reported in North Carolina (personal communication). Stubble height should be

at 6 to 10 inches (15.24 to 25.4 cm) after the animals are removed. Wolf and Fiske (1995) report

using a 35 day rest period between grazing cycles.

For forage purposes, switchgrass, big bluestem, little bluestem, and Indiangrass have mainly

been used to support growing or lactating beef cattle. The growth habit, seasonal forage

distribution, and nutritive composition of these grasses are best suited to this use. A limited

number of studies have examined these grasses for use with sheep but those have found that

sheep digest switchgrass hays less efficiently than do cattle (Vona et al. 1984; Reid et al. 1988b).

Puoli et al. (1992) cited unpublished work by Corsi and Puoli (M. Corsi and J. R. Puoli 1990,

unpublished data) that showed that switchgrass rotationally grazed at initial heights of 40 or 55

cm and defoliated quickly using a high seasonal ewe carrying capacity resulted in reasonable

rates of gain.

NWSG Quality Aspects

Digestibility of Cell Fiber Components

NWSG are different in leaf anatomy, photosynthetic pathway, photorespiration, and 13C to 12C

ratios than the C3 CSG. These differences, and especially the fundamental leaf structure

difference, result in very marked differences in composition and nutritional quality between the

tropical and temperate forage grasses (Moore and Mott 1973; Minson 1981; Norton 1982). These

differences are responsible at least in part for reduced rates of fiber degradation by bacteria and

fungi in the rumen (Akin 1982, 1986; Wilson 1985) and lower digestibility by cattle and sheep

(Minson and McLeod 1970; Minson 1981). In contrast to this, the NWSG in pasture systems in

the northern United States frequently support good rates of gain in grazing cattle making

conclusions based solely on laboratory analyses much less reliable for the NWSG than for the

introduced CSG.

A major disadvantage of NWSG is their rapid decline in digestibility during mid- to late- summer

as the plant matures. Digestion of forage results from a complex interaction between rumen

microorganisms, the rumen environment, previous diet, and forage cell wall structure (Akin 1982).

Differences in anatomical structure, chemical composition, and site and type of lignification in

grass cells have been related to the rate and extent of cell wall degradation in the rumen (Akin
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79

and Robinson 1982). Differences in the amounts of easily digested tissues can affect the rate of

grass leaf blade digestibility (Akin and Burdick 1975) that is compounded by the grazing

selectivity of the animal. It is thought that this decline in digestibility with maturity is in part due to

decreased susceptibility of the cell wall polysaccharides to microbial degradation in the rumen.

The poor degradation of these structural polysaccharides may result from either the close spatial

arrangement of cells in leaves (Hanna et al. 1973) or the composition and structural organization

of the cell wall polymers (Fan et al. 1980). Research targeted at evaluating these hypotheses

include work by Faix and Kaiser (1980), Grabber and Jung (1991 a,b), Grabber et al. (1991),

Grabber et al. (1992), Magai et al. (1994), and Piwonka et al. (1991).

Digestibility of Other Cell Components

Besides differences in fiber components, a number of other nutritional factors may impact the

differences between predicted performance based on chemical tests and actual performance in

live animals. The major factor in this is CP concentration that is reported to be lower for NWSG

especially as they mature. After reviewing the literature, Minson (1981) found that 22 percent of

tropical grass values for CP concentration were less than 6 percent, compared with only 6

percent of values with temperate forages. He considered that CP levels of less than 6 to 8

percent in forage would result in depressed intake by the animal. Crude protein concentration in

NWSG has been found to decline as the grasses mature. It was lower in regrowth material than in

first growth, and it differed significantly between plant components (leaves and stems) (Anderson

and Matches 1983; Griffin and Jung 1983; Koshi et al. 1982; Newell and Moline 1978; Reid et al.

1988a; Taylor and Allinson 1981).

Studies have shown that performance of livestock grazing NWSG is generally greater than would

be expected given their relatively low protein and high fiber concentrations of these grasses

(Abrams et al. 1983; Reid et al. 1988b). Mullahey et al. (1992) compared the ruminal escape

protein from switchgrass and smooth bromegrass [Bromus inermis Leyss.]. Ruminal microbial

degradation of digestible protein in excess of microbial needs results in N loss as ammonia.

Escape protein is dietary protein that is not degraded ruminally but is available for absorption in

the small intestine. This can increase N use efficiency by the animal if adequate N remains

available for microbial growth in the rumen. Mullahey et al. (1992) found that whole-plant escape

protein concentration in switchgrass was 42 percent greater than for smooth bromegrass,

averaged across all growth stages. Escape protein concentration declined with maturity in both

species. Escape protein percentage was similar for smooth bromegrass leaves and stems while

switchgrass stems were generally higher than leaves.

Another factor that influences performance is the clear differences in the concentrations of certain

minerals between tropical and temperate forages (Fleming 1973; Reid et al. 1979; Norton 1982).

Phosphorus concentrations in unharvested switchgrass grown in Texas decreased from 0.23

percent in June to 0.12 percent in November (Koshi et al. 1982). Taylor (unpublished data) found

declines in P concentrations with maturity for switchgrass, Indiangrass, and Caucasian bluestem

in field studies in Louisiana in the early 1980s. Balasko and Smith (1971) noted decreased

concentrations of N, Ca, P, and K in switchgrass as temperature was increased in a growth

chamber study. Temperature did not affect the concentrations of Mg, Na, Al, Fe, Sr, Cu, or Zn but

N fertilization increased concentrations for all but Na, Al, B, and Cu. Friedrich et al. (1977)

reported low S concentrations in switchgrass with an unfavorable N:S ratio although S fertilization

did boost leaf and stem S concentrations.

Animal Studies

As mentioned above, laboratory measurements do not accurately predict animal performance.

Griffin et al., (1980) found that the IVDDM laboratory technique underestimated in vivo digestible

dry matter (DDM) by as much as 17 percentage points in studies with switchgrass and big

bluestem in Pennsylvania. Their studies indicated the importance of animal evaluation in

supporting laboratory forage quality analyses. Still, their findings did indicate that these forages
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80

when harvested at early head emergence or later appeared most suitable for animals with lower

nutrient requirements such as beef cows rather than high performing dairy animals. Vona et al.

(1984) also found that IVDDM underestimated DDM by 10 percent (100 g kg-1) at jointing and 21

percent (210 g kg-1) at heading stage. Vona et al. (1984) concluded that their trials indicated that

when NWSG are harvested at an early stage of growth they provide cattle with a high intake of

digestible energy. They also found that the poorer utilization of the grasses by sheep than by

cattle offers less potential for use of these forages in lamb production systems.

The ideal, season-long pasture system must supply high yields of quality forage throughout the

grazing period. An approach to achieving this type system is to use a series of grasses that differ

in their growth habits and periods of maximum production and combine that with intensive,

rotational grazing to maximize quality and use of the available forage. Studies have shown the

value of various components of this strategy. Conard and Clanton (1963) reported highest animal

gains per hectare and highest average daily animal gains when CSG were grazed heavily in

spring and fall, and WSG were used in summer. Krueger et al. (1974) found the use of WSG

pasture in July and August increased beef gains by 83 percent and that a combination of

separate pastures of cool- and warm-season species provided the highest carrying capacity and

beef production per acre.

Many feeding trials and grazing trials have been conducted on NWSG. Results vary from study to

study but, when managed in a way to maximize animal gains, trials generally show good

performance on NWSG. Readers should refer to the following papers for more detailed

information (Anderson and Matches 1983; Burns et al. 1984; Griffin and Jung 1983; Griffin et al.

1980; Kneebone et al. 1961; Krueger and Curtis 1979; Martin and Hibberd 1990; Newell 1968;

Olsen et al. 1999; Prigge et al. 1990; Reid et al. 1988a,b; Stokes et al. 1988; Vona et al. 1984;

Wolf and Fiske 1995).

Toxicology in NWSG

Forage toxicology came into prominence with producers following the discovery of the presence

of an endophyte fungus in tall fescue [Festuca arundinacea Schreb.] that caused ‘summer slump’,

festucosis, or fescue toxicosis in grazers consuming endophyte infected tall fescue during the

summer months. Although little information is available on animal health problems when grazing

NWSG, it is an area that should not be overlooked. The potential of these native grasses is great

but the management challenges are also great. If producers are forearmed with knowledge, it is

unlikely that a rare combination of events will create an impenetrable barrier to eventual

acceptance of these grasses.

It has been noted in other Panicum species that secondary or hepatogenous photosensitization

sometimes occurs in herbivores grazing these grasses. In this type of photosensitization, a

photodynamic compound, phylloerythrin, is produced from chlorophyll by microbial action in the

digestive tract. Excretion of the compound is decreased by hepatic (liver) injury, caused by a

toxicant in the plant, and photosensitization occurs when hepatic damage becomes generalized

(Jubb et al. 1985). Smith and O’Hara (1978) reported that photosensitization occurred in grazers

on pastures containing P. miliaceum L., P. dichotomiflorum Michx., P. laevifolium Hack, and P.

capillare L. In 1992, Puoli et al. first reported photosensitization in lambs grazing switchgrass. Of

a total of 104 lambs grazed on switchgrass during an abnormally hot, dry summer, 17 showed

photosensitization and eight died. The symptoms were similar to those reported for ‘geeldikkop’ in

sheep (Button et al. 1987). Puoli et al. (1992) reported that mature ewes were not affected and no

signs of photosensitization were noted in suckling lambs grazing switchgrass during a year under

more normal temperature and rainfall conditions. The problem has not been reported in cattle.

However, producers should monitor young animals of all breeds when grazing switchgrass or any

other Panicum species especially during periods of high temperatures and inadequate rainfall.

Crop Models for Perennial NWSG
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

81

A number of models are available to simulate grassland production or predict the stage of

development of the perennial NWSG. A full discussion of these models is not within the scope of

this paper. For further information readers should refer to the following papers (Beaty et al. 1978;

Welles and Norman 1991; Sanderson 1992; Stout 1994; Sanderson and Wolf 1995; Kiniry et al.

1996; Mitchell et al. 1997; Redfearn et al. 1997; Mitchell et al. 1998; Madakadze et al. 1998a,b;

Sanderson and Moore 1999;).

Biomass and Biofuel Usage of Native Grasses

Although not directly related to the forage use of the NWSG, research on the biomass potential

and chemical composition of switchgrass as a source of biofuel does have relevancy for forage

and livestock producers. Research already published and scheduled for publication at this

symposium has shown that switchgrass in particular has potential as a biomass crop in North

America and Eastern Canada (Parrish et al. 1997; Parrish et al. 1999; Madakadze et al. 1999).

The research not only evaluates the yield potential of switchgrass under several cutting regimes

but also reports the chemical composition of switchgrass and the potential removal of nutrients

from soil by the crop.

Madakadze et al. (1999) found that end-of-season switchgrass yields ranged from 9,466 lb A-1

(10.6 Mg ha-1) to 10,895 lb A-1 (12.2 Mg ha-1) for three cultivars grown in Canada. Parrish et al.

(2000) (reported at this symposium) found a 20 to 30 percent increase in biomass yields with two

cuts versus a single cut. They also found that standing biomass declines by about 10 percent

between August and late October and concluded that switchgrass translocates significant

amounts of biomass and N below ground at the end of the growing season. Parrish et al. (1999)

reported that in 1998 the mean switchgrass yield across eight locations for a two-cut system with

N fertilization was from 15,538 lb A-1 (17.4 Mg ha-1) versus 12,859 lb A-1 (14.4 Mg ha-1) for a onecut system. Parrish et al. (1997) reported that lowland cultivars yielded 38 percent more than the

upland cultivars studied when cut once and 12 percent more when cut twice in a season. Average

yields from 1994 to 1996 over eight locations and three years for a single-cut system ranged from

8,841 to 10,895 lb A-1 (9.9 to 12.2 Mg ha-1) and cut twice from 11,520 to 12,949 lb A-1 (12.9 to

14.5 Mg ha-1).

Development of a biofuel industry with switchgrass as one crop component will offer livestock

managers a reason to expand acreage of switchgrass which could be used as an emergency

forage crop when heat or rainfall problems limit the availability of cool-season grass forage. Most

likely, economics will determine how and when the crop will be used wholly or partially as a

forage resource. In addition, the expanded acreage of switchgrass will serve as needed wildlife

habitat and feed/forage reserve.

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Peterson, P.R., S. Hutton, D. Starner, D. Dixon, D. Wolf, and O. Abaye. 2000. Eastern

gamagrass responses to defoliation management. Proceedings of the Second Eastern Native

Grass Symposium, November 17-19, 1999, Baltimore, MD (This volume).

Peterson, P.R., S. Hutton, D. Starner, D. Dixon, D. Wolf, and O. Abaye. 1999. Native warmseason perennial grass responses to cutting and nitrogen management. Field Day August 24,

1999, N. Piedmont Agric. Res. and Education Center, Virginia.

Piwonka, E.J., J.W. MacAdam, M.S. Kerley, and J.A. Paterson. 1991. Separation of mesophyll

from non-mesophyll cell wall tissue in Indiangrass leaf blades. Agron. J. 83:327-330.

Posler, G.L., A.W. Lenssen, and G.L. Fine. 1993. Forage yield, quality, compatibility, and

persistence of warm-season grass—legume mixtures. Agron. J. 85:554-560.

Prigge, E.C., B.A. Stuthers, and N.A. Jacquemet. 1990. Influence of forage diets on ruminal

particle size, passage of digesta, feed intake and digestibility by steers. J. Anim. Sci. 68:4352-

4360.

Puoli, J.R., R.L. Reid, and D.P. Belesky. 1992. Photosensitization in lambs grazing switchgrass.

Agron. J. 84:1077-1080.

Redfearn, D.D., K.J. Moore, K.P. Vogel, S.S. Waller, and R.B. Mitchell. 1997. Canopy

architecture and morphology of switchgrass populations differing in forage yield. Agron. J.

89:262-269.

Rehm, B.W. 1984. Yield and quality of a warm-season grass mixture treated with nitrogen,

phosphorus, and atrazine. Agron. J. 76:731-734.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Rehm, G.W., R.C. Sorensen, and W.J. Moline. 1976. Time and rate of fertilizer application for

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961.

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West Virginia Univ. Agric. and For. Expt. Sta. Bull. 669T.

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Reid, R.L., G.A. Jung, and W.V. Thayne. 1988b. Relationship between nutritive quality and fiber

components of cool-season and warm-season forages: A retrospective study. J. Anim. Sci.

66:1275-1291.

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Manage. 44:574-576.

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establishment of native grass seedlings in Wisconsin. Ecology 34:194-199.

Rogler, G.A. 1954. Seed size and seedling vigor in crested wheatgrass. Agron. J. 46:216-220.

Roundy, B.A., V.K. Winkel, J.R. Cox, A.K. Dobrenz, and H. Tewolde. 1993. Sowing depth and soil

water effects on seedling emergence and root morphology of three warm-season grasses. Agron.

J. 85:975-982.

Sanderson, M.A. 1992. Morphological development of switchgrass and kleingrass. Agron. J.

84:415-419.

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environments. Agron. J. 87:908-915.

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seeds of six grasses. J. Range Manage. 22:240-245.

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Smart, A.J. and L.E. Moser. 1999. Switchgrass seedling development as affected by seed size.

Agron. J. 91:335-338.

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5.

Staley, T.E., W.L. Stout, and G.A. Jung. 1991. Nitrogen use by tall fescue and switchgrass on

acidic soils of varying water holding capacity. Agron. J. 83:732-738.

Stokes, S.R., A.L. Goetsch, and K.L. Landis. 1988. Feed intake and digestion by beef steers

consuming and receiving ruminal insertions of prairie hay differing in level and particle size. J.

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Stout, W.L. 1994. Evaluation of the SPUR model for grasslands of the Northeastern United

States. Agron. J. 86:1001-1005.

Stout, W.L. and G.A. Jung. 1995. Biomass and nitrogen accumulation in switchgrass: Effects of

soil and environment. Agron. J. 87:663-669.

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Stubbendieck, J., S.L. Hatch, and C.H. Butterfield. 1997. North American Range Plants. Fifth

Edition. University of Nebraska Press, Lincoln, Nebraska. pp. 66-67.

Taliaferro, C.M., F.P. Horn, B.B. Tucker, R. Totusek, and R.D. Morrison. 1975. Performance of

three warm season perennial grasses and a native range mixture as influenced by nitrogen and

phosphorus fertilization. Agron. J. 67:389-392.

Taylor, R.W. and D.W. Allinson. 1981. Nutritive evaluation of warm-season grasses in

Connecticut. Storrs Agric. Exp. Sta. Research Report 70.

Tossell, W.E. 1960. Early seedling vigour and seed weight in relation to breeding in smooth

bromegrass, Bromus inermis Leyss. Can. J. Plant Sci. 40:268-280.

Trupp, C.R. and I.T. Carlson. 1967. Progress report of improvement of stand establishment of

smooth bromegrass by recurrent selection for increased seed weight. Proc. West. Grass Breed.

Work Plan. Conf. 19:17-21.

Vona, L.C., G.A. Jung, R.L. Reid, and W.C. Sharp. 1984. Nutritive value of warm-season grass

hays for beef cattle and sheep; Digestibility, intake, and mineral utilization. J. Anim. Sci. 59:1582-

1593.

Warnes, D.D., L.C. Newell, and W.J. Moline. 1971. Performance evaluation of some warmseason prairie grasses in Nebraska environments. Nebr. Agric. Exp. Stn. Bull. 421.

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Agron. J. 83:818-825.

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forages. Proc. XV Inter. Grassl. Cong. pp. 49-55, Kyoto, Japan.

Wilson, A.M. and D.D. Briske. 1979. Seminal and adventitious root growth of blue grama

seedlings on the central plains. J. Range. Manage. 32:209-213.

Wolf, D.D. and D.A. Fiske. 1995. Planting and managing switchgrass for forage, wildlife, and

conservation. Virginia Cooperative Extension Publication 418-013.

Wuenscher, M.L. and G.C. Gerloff. 1971. Growth on Andropogon scoparium (little bluestem) in

phosphorus deficient soils. New Phytol. 70:1035-1042.

Zarnstorff, M.E., R.D. Keys, and D.S. Chamblee. 1994. Growth regulator and seed storage

effects on switchgrass germination. Agron. J. 86:667-672.
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A Grass Manual for North America

Mary E. Barkworth1, Kathleen M. Capels1 and Linda A. Vorobik 2

Abstract

Grasses are the world’s most important plants. They occur in almost every terrestrial ecosystem,

often as the dominant component, provide over 70% of the calories consumed by humans, and

are a conspicuous element in the modified landscapes associated with our homes, recreation

areas, and work places.

Despite their importance, there is no good identification manual for North America’s grasses.

Until recently, the most frequently used reference was Hitchcock’s Manual of Grasses for the

United States, but it covers only the contiguous 48 states, employs a long since discredited

taxonomic treatment, provides rather superficial descriptions for many species, does not include

illustrations for all the included species, has only state-level distribution maps and, of course,

omits all species described, or discovered for the first time in North America, since 1951.

In 1988, the USDA Agriculture Research Service, in conjunction with the Utah Agricultural

Experiment Station and Utah State University, agreed to sponsor development of a new grass

identification manual. This new Manual would treat all grasses that have been found growing in

North America north of Mexico, reflect current taxonomic thought, have comparable descriptions

and illustrations for all the included species, provide more detailed distribution maps, and include

a more comprehensive nomenclatural treatment. In fall, 1999, the management committee of the

Flora North America (FNA) project decided, with our agreement, to recommend to FNA’s

publisher that the Manual be accepted as the grass treatment for that project.

Over 70 taxonomists have helped prepare treatments for the Manual and many more have

provided distributional data. None of these individuals received any compensation from the

project’s funds. Not surprisingly, some, but not all, treatments were a long time coming.

Nevertheless, we now have most of the components for completing the Manual in hand. There

are two keys to genera, one natural and one artificial. These are currently being tested.

Treatments for all genera have been received and are in various stages of editing. About 300

pages of nomenclatural information are almost ready for publication as a separate volume; the

information will be placed on a compact disk for inclusion in the Manual itself. We have

developed a major distributional database, including both locality and county-level data that will

be used in generating maps for contributors unable to obtain the data needed. Lastly, Linda

Vorobik has begun preparing the illustrations needed; a task that had to be delayed until the

treatments had been received.

The new Manual currently includes 237 genera and 1,393 species. About 896 species are

considered native and 331 of the remainder are established introductions. The remaining 166

species include those known only as ornamentals, those known only from one location or from

historical collections, and a few that are known in North America only as species used in cereal

and forage grass breeding programs.

The major obstacle to completing the Manual in the next three years is lack of funding. Funds are

needed to pay both Capels and Vorobik. In addition, we need assistance in developing the

geographic database; including making the maps available over the Web, and in completing

some of the mundane tasks that drain time from both Barkworth and Capels. It is hard to believe

that we shall not find the funding, given the importance of grasses in so many ecosystems.

 

1 Department of Biology, Utah State University and 2

 Department of Botany, University of

Washington
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Cades Cove Meadow and Wetland Restoration

Jenny Beeler1

Cades Cove is a 2,500-acre limestone based valley in the western portion of the Great Smoky

Mountains National Park. This is a very unique area that supports many diverse natural

communities. The National Park Service has designated Cades Cove as a cultural management

zone. The Park Service also determined that the area should reflect the historical time period of

1850-1920. The cabins and churches throughout the cove accurately reflect this time period;

however, the landscape around these structures does not relate to the historical time period.

History of Past Management Practices in Cades Cove

Over the years a number of management practices have drastically changed the landscape of the

cove. A 1936 aerial photograph of Cades Cove illustrates a patchwork appearance of small fields,

ranging in size from 8-12 acres. These small fields eventually were consolidated into much larger

fields for aesthetics or grazing/hay lease permittee convenience. Today the large fescue fields of

60 acres or more do not reflect the historical time period of 1850-1920.

The haying and grazing practices are also very different today. The hay is harvested

mechanically twice a year. This can be detrimental to the wildlife, especially small fawns and

ground nesting birds. Until recently, 800 acres of the cove was leased to an individual who had

500 cattle on the land. In the 1970’s there were up to 1,500 cattle in the cove. In comparison,

during the historical time period each farmer had only 10-20 cows that they grazed on the

mountain balds in the summer. The valley floor was more valuable for cropland than for grazing

cattle.

The final management practice that altered the landscape of the cove was the result of a joint

program of the National Park Service (NPS) and the Soil Conservation Service (SCS). This

program was implemented in the 1950’s and 1960’s in order to increase the amount of farmland

available for modern agriculture, control flooding, and increase farm productivity. Wetlands were

drained, streams were channelized, and tall fescue was planted in the fields.

Wetland Restoration

Today the park managers realize the importance of having a functioning wetland system that

filters and treats runoff before slowly releasing it into the streams. The NPS and SCS project

resulted in 25,000 feet of channelized streams, created ditches, and drained wetlands in Cades

Cove.

In 1995 a wetland restoration project was initiated with research of the past history of the wetland

areas in the cove. Information from the park archives and local SCS offices was collected and

reviewed. Next, each potential site in the cove was visited and documented. The sites were

prioritized according to how much they had been altered in the past and the feasibility of

restoration within the project guidelines. Two sites were chosen for restoration. Vegetation

monitoring was conducted at each site before the restoration in order to document over time the

changes in the vegetation due to the restoration of the hydrology to the areas.

The first site was located in a very unique area of the cove. In the 1940’s a meandering marshy

drainage system was found in this area. A 1965 farm plan of the area details the construction of

two straight V-ditches. Today the ditches are about 5m wide and 1m deep. During the

vegetation monitoring some very unique plants were found in and near the ditches. Because of

this unique vegetation the restoration techniques had to be carefully considered. It was decided

that the best option was to create four soil plugs (dams) throughout the area. Unique plants were

 

1 National Park Service, 107 Park Headquarters Rd., Gatlinburg, TN 37738
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salvaged from the plug locations before soil was deposited into the ditches. The soil used to

create the plugs was first inspected for the presence of exotic species. The finished plugs were

revegetated with the rescued plant material and native grasses. Over the first winter a heavy rain

event washed gullies in each of the plugs. The next spring a log structure was built into the

existing plugs to eliminate the erosion problems. Today the plugs are holding well and beginning

to push the water into the surrounding fields. A variety of amphibians are using the newly

restored areas to lay their eggs.

The second site was a ditch 700m long that had originally been dug with a backhoe in 1964. The

soil had been piled on either side of the ditch creating a soil berm. Since there were no

significant plants found in or near this ditch, the type of restoration techniques used was not as

important in this situation. A bulldozer was used to push the soil berm into the ditch to fill it and

then reshape the natural lay of the land. This was done in the upper 450m of the ditch. In the

lower portion of the ditch the soil berm had been eroded away over the years. Since there was

not enough soil to fill the ditch, three soil plugs were installed in the lower portion. The next year

some hay and log check dams were placed in the upper portion of the ditch in order to slow the

water coming through the area and eliminate some erosion problems. This site is progressing

very well and the water has been forced out of the created ditch and is beginning to naturally

meander through the field. In the lower portion the plugs are forcing water into the surrounding

fields and the amphibians are using these pools to lay their eggs.

Both of these projects have worked very well and we hope that over time the hydrology of these

areas will be restored.

Meadow Restoration

The second part of the 1995 restoration project was the meadow restoration. As mentioned

before, in the 1950’s and 1960’s meadow fescue [Festuca pratensis Huds.] was brought into the

park. At that time fescue was thought to be the best forage grass for grazing and hay production.

It was widely planted throughout the cove. Today fescue is the predominant grass in the cove.

Fields dominated by fescue can be detrimental to small mammals and livestock. A fungus that is

often associated with fescue can cause a decrease in small mammal populations by up to 50%.

Fescue also provides very little nutrition or cover for small mammals, ground-nesting birds, and

insects. In addition, fescue is a mat forming grass through which animals can not travel or find

cover from predators. In contrast, the native grasses grow in clumps, which allows space for

animals to travel, provides excellent nesting habitat, and provides protection from predators. A

fescue field is not very diverse and is very uniform looking. In comparison, native grassland

areas are more diverse in appearance and in species composition.

Our goal in this project was to restore native warm season grasses (NWSG’s) to the fescue fields

and experiment with different management techniques. Three one-acre sites were delineated in

the cove. Two of the sites were in regularly mown hay fields, while the third site was in an

abandoned field. The hay fields were obviously dominated by fescue. In the abandoned field

fescue was present but the native grasses were beginning to reestablish. Of the eight plots

established at each site, four were randomly chosen as treatment plots and the other four as

control plots. Vegetation monitoring was completed at each site, in order to document the

changes that might occur in the native vs. exotic species numbers and in the numbers of the rare

species.

In the fall of 1995 the restoration began with a herbicide application of 0.125% glyphosate. This

was done on a warm day after the second frost when the fescue was actively growing and the

native grasses were dormant. In the spring of 1996 the two hay field sites were planted with a

mixture of Indian grass [Sorghastrum nutans (L.) Nash], purpletop [Tridens flavus (L.) Hitchc.],

hairy clover [Lespedeza hirta (L.) Hornem.], and grass-leaved golden aster [Pityopsis graminifolia

(Michx.) Nutt.]. This seed mix was planted with a Great Plains No-Till Seed Drill. The vegetation
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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monitoring was completed a second time. It was obvious that some control of the fescue was

achieved the first year after the herbicide application.

Another method we wanted to test in the establishment of NWSG’s was prescribed burning. In

the spring of 1997 the treatment plots were burned. Unfortunately, there was not enough plant

material to adequately carry the fire in the plots. In the summer the vegetation monitoring was

completed for the third and last time. The data the third time showed a slight increase in the

number of fescue plants. The species that had been planted did not show up in the plots until

1999. Indian grass can now be found in each of the treatment plots at one of the sites.

Future Projects

In the future we hope to continue restoring NWSG’s to the fescue fields in Cades Cove. In order

to protect the genetic integrity of our native species of grasses, only seeds collected from plants

within the cove will be used for the meadow restoration. These seeds collected from cove

grasses will be planted in seed increase fields of individual species that can be harvested

mechanically in the future. Eventually these seeds will be collected and used in a mixture to

restore other areas of the cove.

Summary

By implementing these management changes in the grasslands and wetlands of Cades Cove the

natural resources will be greatly enriched. The restored meadows and wetlands will create more

habitats for native plant species that previously were found only in limited areas of the cove. The

increased number of native plants will also support more species of invertebrates, small

mammals, birds, and amphibians. These restored areas also present an excellent opportunity to

educate the public about the benefits of a functioning natural community.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Sweetgrass Propagation Project

David Burgdorf, Philip Koch and Tony Bush1

Abstract

Sweetgrass [Hierochloe odorata (L.) P. Beauv.] is a plant of great cultural significance among

many of the North American Indian tribes. Its diverse tribal uses range from medicinal to

cosmetic. Sweetgrass because of its sweet, vanilla-like fragrance is most commonly braided and

burned for ceremonial purposes, or woven into handicrafts. The widespread decline of tribal

sweetgrass stands in the Great Lakes region coupled with the resurgence of American Indian

cultural preservation has created the need and opportunity for the NRCS Rose Lake Plant

Materials Program to assist tribes in the region with rejuvenating these stands.

As sweetgrass is somewhat difficult to grow from seed due to slow development and infertility

problems, plant division is generally the most successful means of reproduction. Sweetgrass

spreads vigorously by often-deep creeping rhizomes. In the spring these rhizomes produce

inconspicuous fruiting stems with sparse, short leaves. Dividing a plant is accomplished by

separating the individual propagules (containing some root material and an identifiable shoot) that

have developed from the rhizomes of a spreading plant. Each propagule can then be placed in a

container for further separation or future planting. Newly separated plants do best if placed in the

shade for 2-3 weeks while their roots establish then transplanted at 1-foot spacings into areas of

partial to full sun.

The original sweetgrass assemblage grown at the Rose Lake facility was collected in Michigan

from historic harvest sites of the Sault Ste. Marie Tribe of Chippewa Indians. The 18 plants

collected in January of 1995 soon developed into 300 plants. With assistance from the tribal

youth the 300 plants were separated into 3000 and planted back in the Sault Ste. Marie tribal

stands by July 1996. To date more than 15 American Indian tribal stands across a 5-state area

have been repopulated with sweetgrass propagated from the original collection.

 

1 USDA-NRCS Rose Lake Plant Materials Center, 7472 Stoll Road, East Lansing, MI 48823
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95

Forage Potential of Switchgrass and Eastern Gamagrass in the Eastern Piedmont

J.C. Burns and D. S. Fisher1

The early presence of switchgrass [Panicum virgatum L.] and eastern gamagrass [Tripsacum

dactyloides (L.) L.] in the Southeast is evidenced by the spotty occurrence of remnant stands

across this region. Lowland-type switchgrass can be found on undisturbed sites such as on oldroad or railroad right of ways, while its relatives [Panicum amarum var. amarulum (Hitchc. and

Chase), P.G. Palmer, and P. amarum Elliott] can be found growing in back of the fore dunes in

the maritime environment of the Atlantic Coast. Remnants of eastern gamagrass stands can be

found in more moist environments, such as undisturbed wetlands and along streambeds and

roadside ditches. Although these forage grasses are generally thought of as being native only to

the tall grass prairie, both have occurred as part of the mixed woodland and grassland vegetation

of the Southeastern USA.

Native grasses in the Piedmont may provide improved wildlife habitat and pasture of higher

nutritive value than those presently grown. Bermudagrasses and bahiagrass, two introduced

species, are the most common perennial grasses grown throughout the region, and both possess

only moderate quality and provide poor wildlife habitat.

Evaluation as pasture

Steer performance and pasture productivity

A summary of several experiments shows the potential quality of switchgrass (SG) and

gamagrass (GG) when continuously grazed. After the first week in June and into September,

steer average daily gains (ADG) were 1.47 lbs for SG and 1.34 lbs for GG. This compared with

0.97 lbs for Tifton-44 bermudagrass. When considering the total grazing season, which begins in

mid-April for SG and GG, steer ADGs were about 2 lbs for both forages. This compared with

about 1.6 lbs during the same period for the widely used tall fescue-bermudagrass system.

In a three-year study in which both gain per animal and gain per acre were determined, the tradeoff between forage of high quality and high productivity is demonstrated (Table 1). In the spring

ADG for tall fescue (TF), SG, and Carostan flaccidgrass [Pennisetum flaccidum Griseb., an

introduced subtropical, perennial forage] averaged over 2 lbs. Both SG and flaccidgrass (FG)

had greater ADG than TF, and this difference is of biological importance. Stocking rate, on the

other hand, was greater for TF, averaging 6.1 steers per acre in the spring compared with 3.6 for

SG and 4.7 for FG.

In the summer, steers grazing Coastal bermudagrass had ADG of 0.93 lbs, which was less than

ADG of about 2 lbs from SG and FG. During this portion of the grazing season BG carried about

10 head per acre compared with 3 to 4 steers per acre for SG and FG. Although BG was inferior

in quality to both SG and FG, it carried about three times as many steers.

The season data (Table 1) show that the productivity of the TF - BG system is not as great as

when the two components appear separately. This is because when TF is being grazed the BG

component is not productive, and when BG is grazed the TF component is not productive. When

the land areas for TF and BG are summed for the season, the stocking rate advantage is lost

when compared to SG and FG, but the productivity in terms of total digestible nutrients (TDN) per

acre is retained. Steers grazing SG and FG were retained on the same land area throughout the

growing season.

 

1 USDA-ARS, Raleigh, NC and Watkinsville, GA; and North Carolina State University, Raleigh,

NC 27695
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

96

Table 1. Quality and productivity of the recommended tall fescue (TF) – bermudagrass (BG)

system compared with Kanlow switchgrass and Carostan flaccidgrass. 1

Spring Summer Season

Forage ADG SR ADG SR ADG SR TDN

(lbs) (hd/ac) (lbs) (hd/ac) (lbs) (hd/ac) (ton/ac)

Tall Fescue 2.05 6.1 --- --- --- --- ---

Bermudagrass --- --- 0.93 10.2 --- --- ---

TF – BG --- --- --- --- 1.28 3.9 2.4

Switchgrass 2.38 3.6 2.03 3.2 2.12 3.3 1.7

Flaccidgrass 2.98 3.6 1.99 3.7 1.99 3.9 1.9

1

See Burns et al. 1984, Agron J. 76:795-800.

Figure 1. Accumulated rainfall (inches) that occurred by each weigh day from April through

September in 1999 compared with accumulated monthly normal (30-yr average) rainfall for the

region (NOAA, National Climatic Data Center, Raleigh-Durham Airport).

0

5

1

0

1

2

0

2

3

0

3

4

0

4/2 5/1 5/2 6/ 6/2 7/6 7/2 8/ 8/1 8/3 9/1 9/2

Accumulated inches of rainfall

 Normal Rainfall

 Rainfall in 1999

Date
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97

Pasture performance under stress

Frequent two to three week droughts occur in the Piedmont during the growing season. Because

of these repeated periods of moisture and temperature stresses, it is advantageous to have

pasture species that are well adapted to such adversity. The 1999 growing season provided such

an assessment of several introduced and native species being evaluated for grazing in the

region. Accumulated rain during the 1999 pasture season was about 10 inches below normal

from May 11 through mid-August (Figure 1).

Figure 2. Accumulated steer weights during the growing season while grazing five experimental

forages. Discontinuity in accumulated weights within a forage treatment occurred when all

animals were removed from the treatment. Numbers in parentheses are steer average daily gain

for each forage. When animals were removed from a treatment, an average daily gain was

calculated for each grazing segment that exceeded four weeks. All values are the mean of two

pasture replicates.

A trial was initiated April 27 with steers grazing pastures of Alamo switchgrass, Iuka gamagrass,

and Roundtree big bluestem [Andropogon gerardii Vitman]. With the onset of moisture stress,

stocking rates were reduced to maintain an excess of herbage mass so as not to limit daily dry

matter intake. Caucasian bluestem [Bothriochloa caucasica (Trin.) C.E. Hubb.] (CBS) pasture

was stocked May 25, but grazing was terminated June 8 as it was for big bluestem (BBS). lb

70

75

80

85

90

95

100

105

110

4/2 5/1 5/2 6/ 6/2 7/ 7/2 8/ 8/1 8/3 9/1 9/2

Date

SG

GG

BBS

CBS

BG

(2.2)

(3.2)

(2.1)

(1.9

(1.6)

(1.2)

(1.7)
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Grazing on GG continued until July 6 while SG pastures remained stocked through September 28

(Figure 2). Bermudagrass pastures were stocked for three intermittent one-week periods with

continuous grazing delayed until July 20. On July 20, BG was stocked and BBS, CBS, and GG

were all restocked, with grazing continuing to September 14 for BBS, CBS, and BG. Both SG

and GG were grazed through September 28. The accumulated steer weights (approaching 1100

lbs) and associated daily gains (>2.0 lbs) noted in Figure 2 clearly show that Alamo SG

performed best under the climatic and edaphic stresses of this season. Iuka GG provided the

next best source of pasture, but steer daily gains were inferior to SG. The other forages did not

perform well under these stresses. Adaptation to such stresses warrants special consideration

when selecting forage species for grazing systems. Information about canopy structure, nutritive

value of the canopy, and the animals’ diet are needed to understand why steers perform better

when grazing SG, GG, and FG compared with BG. Summaries of previous research findings that

address this question are presented below.

Canopy structure and nutritive value

When herbage mass (dry matter in lbs per acre) in pastures of TF, BG, SG, FG, and GG was

from 1,500 to 2,000 lbs per acre, the digestibility estimated by in vitro dry matter disappearance

(IVDMD) of the harvested canopy averaged 68, 57, 63, 64, and 59%, respectively. Both BG and

GG appeared to be lower in nutritive value than the others. The lower IVDMD for BG is

consistent with the lower ADG noted in Table 1, but is inconsistent with the ADG obtained for GG

(other studies).

Separation of the canopy from several studies into leaf, stem (including sheath), and dead tissue

shows that TF is 78% leaves (June sampling), with GG next at 59% leaves, and BG, FG, and SG

lower (Table 2). Switchgrass had the highest proportion of stems (54%), followed by BG, with FG

and GG intermediate, and TF lowest. Except for FG, dead tissue was generally similar, making

up 15 to 19% of the dry matter. The proportions of leaf, stem, and dead tissue for FG were nearly

equal.

The IVDMD of the forage components (Table 2) shows that leaf tissue is generally higher in

digestibility than stem tissue, and both leaf and stem tissue are higher in digestibility than dead

tissue. Exceptions are the digestibility of stem for TF, which is mainly pseudo-stem at a June

harvest, and of GG, which shows little difference in digestibility (IVDMD) between it and the leaf

tissues.

Table 2. Proportion and in vitro dry matter disappearance (IVDMD) of pasture samples from

several studies when separated into leaf, stem, and dead tissue.

Proportion IVDMD

Forage Leaf Stem Dead Leaf Stem Dead

%

Tall Fescue 78 7 15 72 75 42

Bermudagrass 27 47 16 64 59 36

Switchgrass 29 54 19 69 63 52

Flaccidgrass 33 32 35 71 66 55

Gamagrass 59 25 16 64 63 29

These data indicate that the forage grasses evaluated in Table 2 have different canopy attributes

that could differentially alter animal grazing behavior and subsequent daily responses.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

99

Animal diet characteristics

Allowing animals with an esophageal cannula to graze each of the pasture canopies and

collecting the resulting masticate provides information on how the animal interacts with the

morphology of the pasture canopy offered. Examination of the digestibility of the masticated

extrusa, compared with the digestibility of the harvested canopy (Table 3), reveals that steers

selected a diet from the canopy that was 7 to 10 percentage units more digestible. The variation

in neutral detergent fiber (NDF) concentrations generally reflects the variation in digestibility

(IVDMD), but the correlation is negative. An exception was GG, which had high fiber and

relatively high digestibility.

Table 3. In vitro dry matter disappearance (IVDMD) of pasture canopies and the associated

IVDMD and neutral detergent fiber (NDF) of the steers’ diet from several studies.

Pasture Diet

Forage IVDMD IVDMD NDF

%

Tall Fescue 68 76 43

Bermudagrass 57 64 54

Switchgrass 63 72 54

Flaccidgrass 64 72 49

Gamagrass 59 69 60

Ruminants must reduce ingested forage to about 1 mm before it can escape from the reticulorumen. To check for differences among forages for particle size reduction, the masticated

extrusa was freeze dried and passed through a series of sieves to give large (>2.8 mm), medium

(<2.8 and >0.5 mm), and small (<0.5 mm) particles. The proportion of the dry matter composed

of each particle size was determined and then each particle class was analyzed for digestibility

(IVDMD). This provided an assessment of how the different forages fractionated upon initial

ingestion and an estimate of digestibility for each particle size class. The largest proportion of the

large particle class occurred for TF and the lowest for BG. The others (SF, FG, and GG) were

intermediate (Table 4). Associated with the low proportion of large particles for BG was its

highest proportion of medium particles and intermediate portion of small particles. Gamagrass,

on the other hand, had the lowest proportion of medium particles and the highest proportion of

small particles.

Table 4. Proportion and in vitro dry matter disappearance (IVDMD) of large, medium, and small

particles in the steers’ diet from several studies.

Proportion IVDMD

Forage Large Medium Small Large Medium Small

%

Tall Fescue 30 61 9 77 76 70

Bermudagrass 8 72 20 54 66 64

Switchgrass 20 65 15 74 73 68

Flaccidgrass 21 69 10 72 72 68

Gamagrass 16 55 29 80 77 69

It is clear from the IVDMD data (Table 4) that the digestibility of the diet consumed by the steers

grazing BG pasture was inferior to the other species for all three particle sizes examined. This

provides insight as to why steer ADG (Table 1) was consistently less for BG compared with SG

and FG in one study and GG in another study. Further, the IVDMD for the large and medium

particle sizes for GG were extremely high relative to the NDF concentrations reported for the total
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

100

diet (Table 3). Even though GG had a high proportion of small particles, the IVDMD was as high

as noted for SG and FG (Table 4). These data provide evidence why SG and GG generally gave

high and similar ADG even though they differ considerably in morphology.

Evaluation as hay

Both SG and GG may be successfully harvested and stored as hay. Kanlow and Alamo SG have

been evaluated and both require prolonged periods of drying (4 to 6 days), which complicates

haying in the humid Piedmont. Gamagrass dries much quicker than SG because of its high

proportion of leaves and less developed stems. Drying can be greatly aided through teddering

following mowing and conditioning. This process removes the conditioned forage from the

windrow and scatters it over the cut stubble.

Hay harvested with an effort to equalize NDF (cell wall) concentrations provided insight as to why

steers gained more when grazing on native grasses compared with bermudagrass (Table 1). The

subtropical forage harvested had an NDF range of 71 to 75% (Table 5). Tall fescue, although

lower in NDF than the others, was high in NDF for a temperate forage and was probably at the

maximum as the plants were fully headed. Bermudagrass was consumed by steers in highest

amounts (2.7% of body weight) compared with TF, SG, and FG, which were in the same study

(Table 5). Gamagrass, although evaluated in a separate study with wether sheep, showed dry

matter intake similar to the intake (body weight basis) of SG and FG by steers.

Table 5. Quality among native grass hays with similar NDF concentrations.

Hay DM Digestibility1

Forage NDF Intake DM NDF CELL HEMI

(%) (% BW) %

Tall Fescue2 62 2.3 62 62 65 68

Bermudagrass2 74 2.7 50 49 52 54

Switchgrass2 75 2.1 61 65 68 72

Flaccidgrass2 71 2.3 64 68 69 76

Gamagrass3 71 2.4 64 66 68 73

1

 DM = dry matter, NDF = neutral detergent fiber, CELL = cellulose, and HEMI = hemicellulose

2

 Evaluated with steers (see Burns et al.,1985, Agron J 77:933-936). 3

 Evaluated with wether sheep (see Burns et al. 1996, Post Harvest Biol. and Tech 7:261-269).

The apparent digestibilities for dry matter and NDF (cell walls) and constituent fiber fractions,

along with the dry matter intake, show that BG is not as digestible as the other subtropical

grasses but is consumed in larger amounts. This infers a higher passage rate of fiber that is not

very digestible to increase dry matter intake and has been observed previously in herbivores.

Evaluation as silage

The high humidity and the occurrence of frequent thunderstorms across the Piedmont make field

curing of hays, especially of switchgrass, difficult with a high risk of rain damage. Direct

harvesting and preserving as silage would remove the risk of rain damage.

Silage characteristics and quality of switchgrass

Kanlow switchgrass has been evaluated for fermentability as well as quality when harvested at

several growth stages and ensiled directly or after field wilting. Direct cut forage averaged about

25% dry matter compared with 34 to 37% dry matter when wilted (Table 6). The resulting pH was

not as low as desired for a stable silage (pH about 4.0), but it was generally free of mold once the

surface 10 to 12 inches were removed and stable enough for feeding.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

101

Lactic acid generally predominates in good silage and butyric acid should be low. Acetic and

lactic acid concentrations were low and consistent with the observed high pH. Butyric acid was

present and concentrations may be higher than desired in the direct cut, vegetative, and late boot

treatments. Although all forages fermented, the fermentation process did not proceed sufficiently

to ensure

Table 6. Ensiling characteristics of direct cut and wilted switchgrass silage for three growth

stages.

Stages

Vegetative Late Boot Headed

Item Direct Cut Wilted Direct Cut Wilted Direct Cut Wilted

Dry Matter (%) 25.5 35.2 25.2 37.1 24.3 34.0

pH 4.8 4.8 5.1 4.9 4.9 4.6

Acids (%):

 Acetic 2.1 0.9 2.0 0.9 1.9 1.0

 Propionic 0.2 0.3 0.2 0.1 0.1 <0.1

 Lactic 2.8 2.5 1.3 1.7 2.6 2.8

 Butyric 1.1 0.4 1.2 0.4 0.2 <0.1

1

 See Burns et al. 1993, Post Harvest Biol and Tech 3:349-359.

a stable silage. This is attributed to a lack of readily fermentable carbohydrates in the forage.

Additional care in packing needs to be taken with SG and other native grasses to exclude the

maximum amount of air possible at the time of ensiling to aid in the development and the

maintenance of an anaerobic environment.

Evaluation of silage dry matter intake by steers, compared with the same forage field cured as

hay, showed no difference within either the late-boot or the headed growth stages. Dry matter

intake (percent body weight) averaged 1.5% for the late boot stage and 1.4% for the headed

stage. Intakes of about 2.5% of body weight are generally desired. Crude protein concentrations

were < 7% at both growth stages and could be, in part, responsible for suppressed dry matter

intake.

Table 7. Ensiling characteristics of direct cut Iuka and Pete gamagrass.

Late Summer

Spring August September

Item Iuka Pete Iuka Pete Iuka Pete

Dry Matter (%) 18.3 18.5 29.4 24.8 30.8 26.8

pH 4.3 4.2 4.4 6.0 4.3 4.3

Acids (%):

 Acetic 2.4 2.0 0.7 0.1 1.3 1.1

 Propionic 0.1 0.1 <0.1 <0.1 <0.1 <0.1

 Lactic 5.6 6.2 2.6 0.4 4.3 3.8

 Butyric 1.3 1.3 <0.1 <0.1 0.1 <0.1

Ensiling characteristics of gamagrass

Fermentation characteristics of Iuka and Pete gamagrass when cut and ensiled directly have

been evaluated for both spring and late summer harvests. Dry matter concentrations were similar

in the spring for Iuka and Pete, averaging 18.4% (Table 7) while concentrations were higher in

the late summer, averaging 30.1% for Iuka and 25.8% for Pete. The pH was about 4.3 and

generally lower than noted for SG (Table 6). An exception is noted at the August harvest for
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

102

Pete. This forage showed little fermentation as noted by the low acid concentrations and

apparent aerobic decomposition when the silo was opened.

In general, lactic acid dominated and butyric acid was present in the spring harvest but generally

lacking in the late summer harvests. No animal evaluation data of these silages is available at

this time.

Summary

Both switchgrass and gamagrass have potential roles in animal production enterprises in the

Piedmont. Both grasses have the following attributes:

1) They can be grown throughout the Piedmont and Coastal Plains.

2) They can be managed as pasture or harvested and stored as hay or silage.

3) Their pasture canopy morphology provides easy access for selective consumption of green

leaves by grazing animals.

4) Their NDF concentrations are indicative of moderate to low nutritive value, but animal

performance is relatively high because their cell walls are highly digestible.

5) They will support seasonal steer daily gains from pasture of about 2 lbs per day, but the

carrying capacity may be less than introduced subtropical pasture species such as

bermudagrass.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

103

Revegetating Slag Refuse Areas with Native Warm Season Grasses

Tony Bush1

This study was designed to determine how topsoil and fertilizer supplements affect the

establishment of native warm season grasses on a northwestern Indiana slag refuse site. A mix

of five locally collected species of warm season grasses that included big bluestem [Andropogon

gerardii Vitman], little bluestem [Schizachyrium scoparium (Michx.) Nash], Indiangrass

[Sorghastrum nutans (L.) Nash], prairie sandreed [Calamovilfa longifolia (Hook.) Scribn.], and

switchgrass [Panicum virgatum L.] was seeded to plots with and without topsoil additions. Split

plots were either treated with a starter fertilizer or left unfertilized. Data was collected on percent

foliar cover, seeded species counts, non-seeded species counts, and the relative effectiveness of

the warm season grasses for improving wildlife and aesthetic value to the site. The percent foliar

cover, warm season grass counts, warm season grasses as a percent of the total plant

population and effectiveness were significantly higher (P<0.05) in treatments receiving additional

topsoil. Based on comparisons between individual seeded warm season grasses little bluestem

had the highest plant counts relative to its proportion in the mix and exceeded expectation

(P=0.10) across all seeded treatments. Although non-seeded species counts and total plant

counts were generally higher in treatments without topsoil supplements, the differences were not

significant (P=0.05). Likewise, no significant differences (P>0.05) were found between fertilized

and non-fertilized split plots for the features measured.

Introduction

The City of Hammond, Indiana, has had a long association with the steel industry. Slag is the

discarded material resulting from the production of metals from ore, in this case, steel from iron

ore. Past slag disposal practices have resulted in numerous poorly vegetated sites where the slag

refuse was stockpiled. Historically, many of these sites had uniquely diverse plant communities

and were in areas historically used as resting sites by migratory birds.

In response to the situations created by slag disposal, the City of Hammond Parks Department in

partnership with the United States Department of Agriculture – Natural Resources Conservation

Service (NRCS) filed for and received a Great Lakes National Program Office (GLNPO) grant

through the Environmental Protection Agency (EPA) to study site specific methodologies by

which slag refuse areas could be revegetated with native plants. The hope of this study was to

identify methodologies that would create a favorable environment for continued native plant

succession, improve wildlife habitat and improve the aesthetic value of the site.

Methods and Materials

The study was located in the City of Hammond within an area known as Strawberry Island at the

southern end of Lake Michigan. The site was flat with dense, slag-permeated surface and sparse

weedy vegetation. An analysis of the slag content indicated there were no inherent elemental

properties that would inhibit plant growth.

This study was developed as a split-plot design with 4 replications. The selection of treatments

(Table 1) was based on practicality and previous experience in other critical area situations. Nonsterilized loamy topsoil was used in treatments receiving supplemental soil. Framework warm

season grass species were chosen for the seed mix from available local genotypes collected by

the Friends of Gibson Woods. Each was cleaned and tested for purity and viability to determine

pure live seed (PLS) content. Information on the species mix is provided in Table 2.

Table 1. Treatment summary.

 

1 USDA-NRCS, Rose Lake Plant Materials Center, East Lansing, MI 48823
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

104

Treatments Soil Component Seed Component

 1(control) no top soil added not seeded

 2 no top soil added seeded with warm season grass mix

 3 4 inches of topsoil placed over slag seeded with warm season grass mix

 4 4 inch topsoil cap incorporated into

top 4 inches of slag

seeded with warm season grass mix

Table 2. Warm season grass seed mix used in seeded plots.

Species seeds/lb. lbs.

PLS/acre

PLS/plot PLS/sq. ft. % of mix

 Big bluestem 165,000 1.77 5841 6.7 9.5

 Little bluestem 240,000 0.61 2928 3.4 4.8

 Indiangrass 175,000 0.99 3465 4.0 5.7

 Prairie sandreed 274,000 0.82 4494 5.2 7.4

 Switchgrass 389,000 5.73 44579 51.2 72.6

Total 9.92 61307 70.5 100.0

Table 3. Summary of 1998 groundcover composition and warm season grass effectiveness on 4

land treatments.

(average count / square foot)

Treatments

Foliar

Cover

(%)

Warm

Season

Grasses

NonSeeded

Species

Total

Plants

Warm

Season

Grasses

(% of total)

Warm Season

Grass

Effectiveness

(Highest = 1,

Lowest = 9)

** * ns ns * *

Control (no

seed, no soil) 37.0 0.6 17.5 18.1 3.5 9.0

Seeded 38.1 0.9 21.8 22.8 4.0 7.1

Seeded with soil

cap

68.4 4.0 13.5 17.5 22.9 1.6

Seeded with soil

incorp. 68.1 3.4 15.4 18.9 18.2 2.6

* highly significant (1% level)

** significant (5% level)

ns not significant at the 5% level

The site was disked to remove existing vegetation and treatment plots were established in early

summer 1996. Each plot measured 8.7 x 100 ft and was divided at the 50 ft mark into fertilized

and not fertilized subplots. Seeded plots were hand broadcast with the mix at a PLS rate of

approximately 10 lbs/acre and raked to provide better seed to soil contact. After seeding 12-12-

12 fertilizer was broadcast on the appropriate subplots at a rate of 1000 lbs/acre. The study area

was mowed several times during the first year and sprayed once with 2,4-D in October for weed

control.

In October 1997 a line transect approach was used to obtain preliminary data on the site.

Information was collected on plant type or species, and plant vigor at each of 50 points, spaced 1

foot apart, within each of the subplots. A total of 1600 points were sampled (50 points x 2

subplots x 4 treatments x 4 replications). A report on the 1997 findings was issued in early 1998.

Results of consequence will also be discussed in this report.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

105

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

control seeded seeded, capped seeded, incorp.

Treatments

Foliar Cover (%)

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

control seeded seeded, capped seeded, incorp.

Treatments

Warm Season Grass

(plants/sq. ft.)

 a a

 b b

Figure 1. Average percent of ground covered by aerial portion of plants over 4 types of land

treatments in 1998: bars with no common letters are significantly different by Duncan’s multiple

range test at the 5% level.

 a a

 b b

Figure 2. Average warm season grass plants per square foot over 4 types of land treatment in

1998: bars with no common letters are significantly different by Duncan’s multiple range test at

the 5% level.

In October 1998 a second collection of data was completed on the study. However, instead of a

line transect, measurements were taken from 4 randomly located square foot sections in each of

the subplots. Data was recorded on % foliar cover, number and type of planted species and the

number of non-planted species for each of the sections. A visual observation was also taken for

each subplot on the effectiveness of the planted species in providing improved wildlife habitat and

aesthetic value to the land.

Results and Discussion
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

106

0.0

5.0

10.0

15.0

20.0

25.0

control seeded seeded, capped seeded, incorp.

Treatments

Warm Season Grasses 

(% of total count)

Changing the method of collecting data from a line transect (one-dimensional view) in 1997 to an

area transect (two-dimensional view) in 1998 caused some difficulty in comparing the data.

Although some correlations can be drawn, this report will center on the information gathered in

1998 (Table 3). Considering the nature of the seeded species and the objectives of this study it is

believed that the second year data is a more reliable picture of the site conditions and the

potential for revegetating these slag sites.

Statistics for the categories that reached a level of significance (5% or greater) showed the sharp

distinction between the treatments where soil was added and those where soil was not added. In

treatments with additional soil the percent of foliar cover nearly doubled but the percent of warm

season grasses and their average counts per square foot were 4 to 7 times greater (Figures 1-3).

Mean separation in each of these cases revealed a significant difference between those

treatments receiving supplemental soil and those that had not.

 a 

 a

 b b

Figure 3. Average percent of warm season grasses in total plant count over 4 types of land

treatment in 1998: bars with no common letters are significantly different by Duncan’s multiple

range test at the 5% level.

The 1997 data (Table 4) is consistent with the 1998 data. As in 1998 the percent vegetative

cover (comparable to foliar cover), and warm season grass counts and percents of total

vegetation were substantially higher (P=0.01) in treatments with the soil additions.

Also of importance are the categories that were not significantly different in 1998, non-seeded

species and total plant counts. Adding topsoil to the slag substantially increased the number of

seeded warm season grasses but it did not statistically affect the non-planted or total vegetation

counts (Figure 4).

Visually the vigor of all plants in the plots with topsoil additions was more pronounced, however, it

was particularly noticeable in the warm season grasses. Each subplot was rated for

effectiveness of the warm season grasses in improving wildlife habitat and adding aesthetic value

to the site (Figure 5). This was essentially a measure of plant numbers and health. The soil

treated plots, consistently and dramatically, had higher ratings than those that had no soil

additions.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

107

Statistics and observations show that where topsoil was supplemented seeded species progress

in number and health much better than the non-seeded species. This likely accounts for the

increase in foliar cover.

Warm season grass data include a breakdown by species. However, it is important to consider

the actual counts in relation to their individual proportions in the seed mix. Multiplying the total

warm season count in a treatment by the proportion of a species in the mix (Table 2) gives the

expected count for that species in a particular treatment. The values for actual and expected

counts for each species in a total sample area of 32 square feet are provided in Table 5.

Table 4. 1997 vegetative cover and warm season grass data.

Treatments Vegetative

Cover (%)1

Warm Season

Grasses (Count)2

Warm Season Grasses

(% of total vegetation) 1

Control (no seed,

no soil) 63.0 b 0 b 0 b

Seeded 61.5 b 8 b 3.3 b

Seeded with soil cap 86.7 a 108 a 31.1 a

Seeded with soil incorp. 92.2 a 69 a 18.7 a

Treatments with no common letters are significantly different by Duncan’s multiple range test at

the 1% level

 1

 average of 4 replication

 2 out of 400 observations

A Chi-square analysis was completed to determine if the actual counts were statistically the same

as the expected counts. Big bluestem fell significantly (5% level) short of expected counts in the

soil-incorporated treatment; prairie sandreed had significantly (highly at 1% level) fewer plants

than expected in both supplemental soil treatments. Little bluestem was the only species that

significantly (highly at 1% level) exceeded expected counts, and that was accomplished in all 3

seeded treatments.

Furthermore, as shown by the extrapolated warm season grass counts per 100 seeds planted

(Figure 6), most species performed better in one or both of the treatments where soil was added.

Again, little bluestem had a comparatively higher percentage than any other species in each of

the seeded treatments. The existence of these species in the control (unseeded) plots suggests

possible self-reseeding and spread by rhizomes which would influence the actual counts.

However, the counts are indicative of the relative success of the species under each of these

conditions.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

108

1.0

2.0

3.0

4.0

5.0

6.0

7.0

8.0

9.0

Effectiveness 

control

seeded

seeded, capped

seeded, incorp.

Figure 4. Plant composition of plots on the 4 land treatments in 1998.

 a

 b

 c

 d

Figure 5. Comparative effectiveness of the warm season grasses in improving wildlife habitat and

aesthetic value to the site on the 4 land treatments in 1998: treatments with no common letters

are significantly different by Duncan’s multiple range test at the 5% level.

0.0

5.0

10.0

15.0

20.0

25.0

control seeded seeded,

capped

seeded,

incorp.

Treatments

Plant Composition of Plots

(ave. plant counts/ sq. ft.)

warm

season

grasses

non-seeded

species
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Table 5. Total warm season grass count, and actual and expected warm season grass counts by

species on the 3 seeded treatments in 1998.

32 square foot total sample area

Big Bluestem Little

Bluestem Switchgrass Indiangrass Prairie Sandreed

Treatment

Total

WSG

Count Actual

Count

Expt.

Count

Actual

Count

Expt.

Count

Actual

Count

Expt.

Count

Actual

Count

Expt.

Count

Actual

Count

Expt.

Count

Seeded 29 4 2.8 *6 1.4 18 21.1 0 1.7 1 2.1

Seeded,

cap

128 14 12.2 *18 6.1 89 92.9 7 7.3 *0 9.5

Seeded,

incorp 110 ** 3 10.5 *21 5.3 82 79.9 4 6.3 *0 8.1

* highly significant (1% level)

** significant (5% level)

 all others are not significantly different

Figure 6. 1998 warm season grass counts per 100 seeds planted in the 3 seeded treatments, (*)

extrapolations based on sample data.

0.0

10.0

20.0

30.0

40.0

50.0

60.0

70.0

80.0

90.0

seeded seeded, capped seeded, incorp

Treatments

Warm Season Grass Counts* 

(per 100 seeds sown of each species)

big bluestem

little bluestem

switchgrass

indiangrass

prairie

sandreed
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Table 6. Summary of 1998 groundcover composition and warm season grass effectiveness on

subplots.

(average count / square foot)

 Subplots

Foliar

Cover

(%)

Warm

Season

Grasses

NonSeeded

Species

Total

Plants

Warm

Season

Grasses

(% of

total)

Warm Season Grass

Effectiveness

(Highest = 1, Lowest = 9)

ns ns ns ns ns ns

 no

fertilizer 50.6 2.3 17.8 20.2 11.6 5.1

 fertilizer 55.2 2.2 16.3 18.5 11.7 5.1

ns not significantly different at 5% level

Table 7. Summary of 1998 ground cover composition and warm season grass effectiveness on

treatment and subplot interaction.

(average count / square foot)

Treatments/

 Subplots

Foliar

Cover

(%)

Warm

Season

Grasses

NonSeeded

Species

Total

Plants

Warm

Season

Grasses

(% of total)

Warm

Season

Grass

Effectiveness

(Highest = 1,

Lowest = 9)

ns ns ns ns ns ns

no seed, no soil

 no fertilizer 34.7 0.9 18.9 19.9 4.7 9.0

no seed, no soil

 fertilizer 39.4 0.3 16.0 16.3 1.9 9.0

seeded, no soil

 no fertilizer 39.1 0.8 23.6 24.3 3.1 7.3

seeded, no soil

 fertilizer 37.2 1.1 20.1 21.2 5.0 7.0

seeded, soil cap

 no fertilizer 61.6 3.9 15.5 19.4 20.3 1.8

seeded, soil cap

 fertilizer 75.3 4.1 11.5 15.6 26.1 1.5

seeded, soil incorp

 no fertilizer 67.2 3.7 13.3 17.0 21.7 2.5

seeded, soil incorp

 fertilizer 69.1 3.2 17.6 20.8 15.4 2.8

ns not significantly different at 5% level

There were no significant differences between the fertilized and non-fertilized subplots across all

categories (Table 6). Likewise, the interaction between treatments and subplot factors was not

significantly different in any category (Table 7). This indicates most, or all, of the differences are

a result of the treatment effect and not the subplot (fertilizer) effect or an interaction between the

two treatments.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

111

Conclusions

The foremost conclusion of this study is that the warm season grass mix performed far better,

both in number and vigor, on the soil amended areas. Although the non-seeded species, mostly

weeds, were somewhat improved in vigor on these same areas, their numbers were not. This

suggests a strong competitive edge to the native grass mix where soil was added. The extensive

root systems, typical of warm season grasses, probably figured greatly into these results but it is

beyond the scope of this study to assess the possible soil-climate-plant interactions.

A rule of thumb is that a warm season grass planting will most likely be successful if it has two

strong plants per square foot in the second year after planting (Dickerson, et. al. 1997). Although

the overall bulk of the grasses was generally less than what would be found on a deep soil site,

both of the treatments receiving supplemental soil doubled or nearly doubled the plant count.

The two treatments not receiving soil additions reached less than half that goal (Table 3, Figure

2). Enhanced wildlife benefits and aesthetic value to the land are, of course, commensurate with

this improved development. This study identifies approaches using additions of topsoil that

enhance the establishment of native warm season grasses on Indiana slag refuse sites.

Fertilizer additions to the subplots did not affect the growth of the grass species used in this

study. Varying the application rate or blend would most likely produce different results. However,

a successful stand of warm season grasses was produced within a respectable period of time

without fertilizer additions.

As to the individual species, little bluestem was the only one to statistically exceed expected

counts, substantially outperforming all the others. At the other extreme, prairie sandreed fell

severely short of expectations. The other species for the most part met expected counts. This

suggests some species may not be appropriate for use under these growing conditions while

others seem to flourish. However, keep in mind that plants are successional and develop at

different rates, and the makeup of any community may change over time.

Finally, the warm season grasses are long-lived but are also relatively slow in above ground

development compared to other common species. Good pre-planting weed control and proper

management, particularly in the first two years after planting, will considerably improve the

chances for a successful planting.

Acknowledgement

Under the terms of Agreement No. 68-52KY-6-649 with the City of Hammond, NRCS, through the

Rose Lake Plant Materials Center, designed and evaluated the methodologies used in this study.

This project was completed through the cooperation of the City of Hammond, Parks Dept.; USDANRCS, Rose Lake PMC and Lake County Field Office; GLNPO, EPA; The Nature Conservancy;

Friends of Gibson Woods; Allen Landscape Construction; and the Lake County Soil and Water

Conservation District.

References

Dickerson J., et al. 1997. Vegetating with Native Grasses in Northeastern North America. Ducks

Unlimited Canada. 63 pp.

[ITIS] Integrated Taxonomic Information System. 1998. Biological Names, Version 4.0 (on-line

database). URL:http://www.itis.usda.gov/plantproj/itis/itis_query.html (updated December 1998.)
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

112

Applied Native Grass Restoration Projects in Western North Carolina

Jon Calabria1

Changing land use patterns and their resultant modification of the landscape have steadily

degraded the Southern Appalachians. Although several decades of restoration have begun to

reverse past degradation, these environmentally focused efforts have seldom addressed the

public’s need for aesthetic appreciation, recreation amenities, and environmental education. In

contrast, several projects in Western North Carolina illustrate efforts to address both the need for

ecological restoration and the public’s need for rejuvenation and recreation in natural settings.

Brevard College Wetland Garden

Brevard College has completed two projects: 1) a wet detention basin that improves water quality

and 2) a streambank stabilization program. These stabilization and restoration efforts will

improve water quality and increase biodiversity by reconnecting the stream channel with the flood

plain. Streamside greenways and pocket parks along the campus stream will provide park users

opportunities to interpret these unique stormwater mitigation features and stream stabilization

techniques.

Headwaters

Headwaters Club emulates a rustic Scottish golf course embraced by indigenous grasses and

forbs. Although the last minute addition of mostly exotic wildflowers and annual rye for additional

erosion control significantly altered the restoration program, users will be exposed to an

ecologically beneficial landscape that outweighs traditional treatments of these areas.

Meadow Ridge

Meadow Ridge is a development that surrounds reserved open space. Homesites surround an

open space that consists of a meadow that encloses a fescue clearing used for recreation. The

long-term restoration effort focuses on recreating a grassy bald community. The restoration

consisted of clearing the failing fir and spruce tree plantation and establishing a pioneer crop of

indigenous ryes and other grasses, including several forbs to increase interest and appeal.

These efforts to combine restoration with environmental education and aesthetics are of critical

importance to the ecological restoration movement. Restorations that invite interaction have

tremendous opportunity to influence public opinion and allow practitioners to address the most

seriously degraded environments.

 

1

 ASLA, Landscape Architect , Scott Melrose & Associates, PA, Asheville, NC
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

113

Estimating Digestibility in Eastern Gamagrass

Joel L. Douglas1, Scott D. Edwards1 and David J. Lang2

Equations to predict total digestible nutrients (TDN) were developed for a variety of introduced

perennial forage grasses and legumes, and annual small grain forages (Undersander et al. 1993).

Livestock producers and forage specialists use TDN equations to estimate the feed value of

different forages and determine nutrient supplement needs. Quality estimates for crude protein

(CP), acid detergent fiber (ADF) and neutral detergent fiber (NDF) are used in various equations

to predict TDN. Age of forage at harvest is among several factors influencing quality estimates

that will ultimately effect TDN. Because many TDN equations give emphasis to introduced

forages, they have limited use for predicting TDN of native forage grasses such as eastern

gamagrass [Tripsacum dactyloides (L.) L.].

The USDA-Natural Resources Conservation Service (NRCS) Jamie L. Whitten Plant Materials

Center (PMC), Coffeeville, Mississippi has selected an accession of eastern gamagrass

(9062680) for future release as a potential forage crop in the southeastern U.S. Information is

needed on the effect of clipping frequency on quality estimates and true digestibility of 9062680.

Therefore, the objectives of this study were to determine the effect of clipping frequency (CF) on

forage quality estimates for ADF, NDF, CP and lignin (L), and determine if these estimates could

be regressed on in vitro dry matter digestibility (IVDMD) to estimate digestibility of the grass.

Methods

The 118 samples used in this study were collected from replicated plots clipped on a 30 and 45

day CF in 1996-1998 at the USDA-NRCS Jamie L. Whitten PMC near Coffeeville, MS. For

specific details on experimental design, clipping management, and fertilization, refer to paper by

Edwards et al. (2000) published in this Proceedings.

In 1996, 30 day harvests were made 14 June, 15 July and 12 August and the 45 day harvests

were made 28 June and 12 August. In 1997, 30 day harvests were made 14 May, 19 June, 18

July and 18 August and the 45 day harvest were made 19 May, 30 June, and 11 August. In

1998, 30-day harvests were made 22 May, 18 June, 24 July and 3 September and 45 day

harvests were made 22 May, 30 June, and 25 August.

Harvested material was weighed green in the field and random samples collected for dry matter

(DM) yield, %N, ADF, NDF, L, and IVDMD. Samples were dried at 55°C for 16 hours

(Undersander et al. 1993). Percent N was determined from Kjeldahl N digest using flow injection

analysis on a Lachat Quick Chem Automated Ion Analyzer (Lachat Instruments, Milwaukee, WI).

Crude protein was estimated by multiplying %N by 6.25. Acid detergent fiber, NDF, L, IVDMD

were determined by the procedures of Goering and Van Soest (1970) with IVDMD utilizing a

DaisyII Incubator and an ANKOM200/220 Fiber Analyzer (Cherney et al. 1997). Data was subjected

to analysis of variance and step wise regression procedure for general linear models in SAS (v

6.12, (1996) SAS Institute Inc., Cary, NC). Duncan’s multiple range test (DMRT) at the 5% level

of probability separated significant differences between means.

 

1

USDA-Natural Resources Conservation Service, Jamie L. Whitten Plant Materials Center 2533

CR 65 Coffeeville, MS 38922; 2

Associate Professor of Agronomy, Department of Plant and Soil

Sciences, Box 9555 117, Dorman Hall Mississippi State, MS 39762
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

114

Results

Yield

There was a marked decrease in DM yield in 1998 for the 30 day CF (Table 1). The grass was

slow to recover from winter dormancy in 1998 and weed competition became a problem as the

stand declined during the year. Brakie (1998) reported that a 30-day CF weakened stands of

Texas ecotypes of eastern gamagrass in eastern Texas. This frequent defoliation coupled with

morphological development and physiological processes of the plant may have contributed to a

reduction in organic reserves in the above ground shoots that limited regrowth and thus, lowered

DM yield in 1998 (Dewald and Sims 1981). Above average growing season rainfall totals in 1996

and 1997, particularly in June, may have contributed to DM yield similarities between CF (Table

2). Remarkably, DM yield of 9062680 harvested in 1998 with a 45 day CF was comparable to

yields observed in 1996 and 1997 and produced 333% more DM yield than the 30 day CF despite

lower than average rainfall in 1998. A visual investigation of the plants in the 30-day CF plots

found them to be less vigorous and slower to recover following defoliation than plants clipped in

the 45-day CF plots in 1998. Dry matter yields reported for 9062680 are comparable to those

reported for PMK-24 eastern gamagrass in south central Missouri and southern Illinois (Brejda

1997; Faix et al. 1980).

Quality

The 30-day CF typically produced lower fiber, higher protein and IVDMD than the 45 day CF in

1996-1998 (Table 3). In 1996 and 1998 the 30 day CF significantly increased IVDMD by 3%

units and 6% units, respectively, compared to the 45 day clipping frequency. The IVDMD values

for 9062680 for both clipping frequencies are higher than those reported for ‘Coastal’

bermudagrass [Cynodon dactylon (L.) Pers.] harvested at four weeks (Ball et al. 1991). The 30-

day CF significantly decreased ADF by 6% units in 1996. In comparing the 3-year average, the

30-day CF produced a significantly lower ADF and a significantly higher protein and IVDMD than

the 45-day CF but the magnitude of these differences were small. Brejda et al. (1994) and

Horner et al. (1985) reported similar ADF, protein, and lignin but lower NDF for eastern

gamagrass in their studies. The average IVDMD for 9062680 was 18% units higher than those

reported for PMK-24 eastern gamagrass (Brejda 1994; Faix et al. 1985). However, Burns et al.

(1992) reported ingestive masticates of ‘Pete’ eastern gamagrass ranged from 64 to 80% IVDMD.

True digestibility of eastern gamagrass may be higher than indicated by conventional Van Soest

estimates. Horner et al. (1985) reported that eastern gamagrass was nearly equal to alfalfa

[Medicago sativa L.] as a source of hay for lactating dairy cows.

Table 1. Season total DM yield of 9062680 eastern gamagrass as influenced by CF in 1996-

1998 and 3-year average, Coffeeville, MS.

Year

Frequency 1996 1997 1998 3 yr. avg.

------------------------------------lbs/acre--------------------------------------

30 12 494 a* 13 123 a 3707 a 9775 a

45 10 361 a 14 652 a 12 329 b 12 447 b

* Means in columns within year and 3 year average followed by the same letters are not

significantly different at P<0.05 according to DMRT.

Estimating digestibility

Undersander et al. (1993) identified numerous digestibility equations for different regions of the

U.S. utilizing ADF, CP, and NDF to predict TDN of various perennial and annual grasses,

legumes, and other crops. In this study, regression analysis produced similar equations for the

30 and 45 day CF when ADF, NDF, CP and L estimates were regressed on IVDMD (data not

shown). Therefore, data were pooled for final statistical analyses.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

115

Table 2. Rainfall received during the growing season for 1996 – 1998 and 20 year average,

Coffeeville, MS.

Rainfall

Month 1996 1997 1998 20 yr. Avg.

 -----------------------------inches----------------------------

March 5.20 7.83 6.57 5.75

April 5.94 3.15 5.59 5.47

May 3.90 7.17 4.53 5.75

June 11.77 12.32 1.97 4.84

July 4.80 4.09 4.09 4.33

August 3.50 3.15 3.62 3.27

September 7.52 5.59 0.28 4.17

Total 42.64 43.31 26.65 33.58

Regression analysis gave different equations each year (Table 4). Although the regression

equations for 1996-1998 were highly significant, their correlation was weak. The equation

produced in 1996 with NDF, CP and L gave the highest correlation. Bidlack et al. (1999) found

that IVDMD was highly correlated with L and CP in the genotypes of eastern gamagrass in their

study. When combined over years, no combination of quality estimates produced a consistent

equation. However, ADF and CP remained in the over all equation but was a weak primary

influence. Many state and university forage testing laboratories in the southeastern U.S. use ADF

and CP for predicting TDN of cool and warm season grasses and legumes, grass-legume

combinations, and other forages (http://www.uark.edu/depts/agronomy/facpage/west/tdn). The

overall equation has relevance for estimating digestibility of 9062680. Additional laboratory

analysis may be necessary before an equation can be verified. In addition, in vivo digestibility

studies need to be conducted.

Table 3. Quality estimates of 9062680 eastern gamagrass as influenced by CF in 1996-1998

and 3-year average, Coffeeville, MS.

 Quality estimates

Frequency ADF1 NDF2 CP3 L4 IVDMD5

1996 ---------------------------------------%-------------------------------------

 30 38 a* 79 a 10 a 8 a 79 a

 45 44 b 78 b 8 b 11 a 76 b

1997

 30 40 a 80 a 10 a 8 a 74 a

 45 42 a 81 a 10 a 11 a 74 a

1998

 30 42 a 78 a 11 a 8 a 77 a

 45 41 a 77 b 10 a 12 b 71 b

3 yr. Avg.

 30 40 a 79 a 10 a 8 a 77 a

 45 42 b 79 a 9 b 11 a 74 a

1 - acid detergent fiber; 2 - neutral detergent fiber; 3 - crude protein; 4 - lignin; 5 - in vitro dry

matter digestibility.

* Means in columns within year and 3 year average followed by the same case letters are not

significantly different at P<0.05 according to DMRT.

Conclusions

A 45-day CF appears to be suited for sustainable yields and favorable quality for 9062680

eastern gamagrass. There was no combination of quality estimates that produced a consistent
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

116

equation for estimating digestibility of the grass. However, CP and ADF remained in the overall

equation but were a weak influence. The overall equation has relevance for estimating

digestibility of 9062680 but additional laboratory analysis will be conducted before a final equation

is verified.

Table 4. Regression equations, R2

 and P values for IVDMD (Y) vs. quality estimates (ADF1,

NDF2

, CP3 and L4) of 9062680 eastern gamagrass for 1996-1998 and combined over years.

Year Regression equation R2 P value

1996 Y = 85.6 - 0.33 * NDF + 1.63 * CP + 0.24 * L 0.63 0.0001

1997 Y = 67.7 - 0.27 * ADF + 0.22 * NDF 0.16 0.0242

1998 Y = 77.3 - 0.43 * L 0.19 0.0112

Combined over yrs. Y = 77.9 - 0.21 * ADF + 0.56 * CP 0.13 0.0004

1 - acid detergent fiber; 2- neutral detergent fiber; 3 - crude protein; 4 - lignin.

References

Ball, D. M., C. S. Hoveland, and G. D. Lacefield. 1991. Forage quality. p. 124-132. In Southern

forages. Potash and Phosphate Inst., Norcross, GA.

Bidlack, J. E., J. E. Vaughan, and C. L. Dewald. 1999. Forage quality of 10 eastern gamagrass

[Tripsacum dactyloides (L.) L.] genotypes. J. Range Manage. 52: 661-665.

Brakie, M. R. 1998. Yield and quality of eastern gamagrass selections as affected by clipping

frequency and N rates. M. S. Thesis. Stephen F. Austin St. Univ. Nacogdoches, TX.

Bredja, J. J., J. R. Brown, T. E. Lorenz, J Henry, and S. R. Lowery. 1997. Variation in eastern

gamagrass forage yield with environment harvest and nitrogen rates. Agron. J. 89:702-706.

Bredja, J. J., J. R. Brown, J. M. Asplund, T. E. Lorenz, J. L. Reid and J. Henry. 1994. Eastern

gamagrass fermentation characteristics and quality under different N rates. J. Prod. Agric.,

7:477-482.

Burns, J. C., D. S. Fisher, K. R. Pond, and D. H. Timothy. 1992. Diet characteristics, digesta

kinetics, and dry matter intake of steers grazing eastern gamagrass. J. Amin. Sci. 70:1251-1261.

Cherney, D. J., M. J. Traxler, and J. B. Robertson. 1997. Use of ankom fiber determination

systems to determine digestibility. NIRS Forage and Feed Testing Consortium Annual

Conference. Madison, WI.

Dewald, C. L. and P. L. Sims. 1981. Seasonal vegetative establishment and shoot reserves of

eastern gamagrass. J. Range Manage. 34 (4): 300-3004

Faix, J. J., C. J. Kaiser, and F. C. Hinds. 1980. Quality, yield and survival of asiatic bluestems

and an eastern gamagrass in southern Illinois. J. Range Manage. 33:388-390.

Goering, H.K and P.J. Van Soest. 1970. Forage Fiber Analysis (Apparatus, Reagents,

Procedures, and Some Applications) USDA Agriculture Handbook No. 379.

Horner , J. L., L. J. Bush, G. D. Adams, and C. M. Taliaferro. 1985. Comparative nutritional value

of eastern gamagrass and alfalfa hay for dairy cows. J. Dairy Sci. 68:2615-2620.

Undersander, D., D. R. Mertens and N. Thiex. 1993. Forage analysis procedures. National

Forage Testing Association. Omaha, NE.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

117

A Comparison of Seed Cleaning Techniques for Improving Quality of

Eastern Gamagrass Seed

Joel L. Douglas1, Janet M. Grabowski1 and Bennie C. Keith2

Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a native warm-season perennial

bunchgrass with potential for livestock forage and cropland erosion control in the Southeast (Ball

et al. 1991; Dewald et al. 1996). Attempts to establish stands from seed have given inconsistent

results. The seed of eastern gamagrass is protected between a rachis internode and an outer

glume association known as a cupulate fruitcase (Galinat 1956). The cupulate fruitcase has been

shown to inhibit germination in some genotypes of eastern gamagrass, but germination can be

enhanced with cold-moist stratification for 60 days followed by exposure to temperatures of at

least 30° C (Anderson 1990). Indeterminate seed maturity is another factor that indirectly affects

seed quality. A typical combine-run harvest consists of complete seed units (cupulate fruitcase

with filled seed), incomplete seed units (cupulate fruitcase with unfilled seed) and other nonviable inert matter. Inability to adequately separate filled seeds from unfilled seeds may lead to

poor establishment (Ahring and Franks 1968).

Air screen cleaners (ASC) are commonly used for cleaning eastern gamagrass seed. They

remove most of the inert matter and a portion of immature seed units, but are not capable of

separating complete seed units from incomplete ones. Similarities in size and shape, and the

inability of the system’s air flow mechanism to separate complete units from incomplete units

complicates cleaning operations, thus both types are included in the final product. A South

Dakota Seed Blower has been shown to improve separation of complete seed units from

incomplete seed units of eastern gamagrass and increase germination potential 73 to 95%

(Ahring and Franks,1968). However, the South Dakota Seed Blower was designed for

processing limited seed quantities and does not have the capacity to accommodate large seed

lots.

An air fractionating aspirator (AFA) is a seed cleaner that utilizes terminal velocity to separate

light materials from heavy materials and partitions them into fractions. Gravity separator (GS)

uses specific gravity created by forced air and oscillating movement to separate seed

components according to density. Both of these cleaning techniques have potential to improve

seed quality of eastern gamagrass.

There is no published literature on the use of an AFA or GS to improve seed quality of eastern

gamagrass once the seed has been partially cleaned with an air screen cleaner. Therefore, the

objective of this study was to compare percent fill and percent germination of fractions separated

by an AFA and GS, and contrast these results to those for a single fraction from an ASC.

Methods

Three lots were chosen for the experiment. Lots A, B, and C were harvested with a John Deere

4400 conventional combine in September 1992, 1993, and 1995, respectively, from a stand of

eastern gamagrass at the USDA-Natural Resources Conservation Service, Jamie L. Whitten

Plant Materials Center (PMC) near Coffeeville, Mississippi. Seed units and other components of

the harvest were spread evenly on a concrete floor and allowed to air dry in a ventilated

warehouse for approximately one week. An ASC (Clipper M2B, A. T. Ferrell and Co., Saginaw,

MI), equipped with an upper and lower screen, was used for cleaning. Seed units were stored in

 

1

 USDA-Natural Resources Conservation Service, Jamie L. Whitten Plant Materials Center, 2533

CR 65 Coffeeville, MS 38922; 2 Mississippi Seed Improvement Association, Mississippi State, MS

39762

Accepted for publication in Journal of Seed Science and Technology
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

118

cloth bags and placed in a storage vault maintained at 13° C and 45% relative humidity. In

January 1997, a 4.5 kg random sub-sample was collected from each lot.

A 200 gram random sub-sub-sample was obtained from each 4.5 kg sub-sample and separated

into four fractions with an AFA (Carter-Day Model No. CF 21, Minneapolis, MN). Each fraction

was weighed to determine its percentage relative to the sample size.

A GS (Oliver MFG, Rocky Ford, CO) was used to separate a 3.5 kg sub sample of lot C into two

fractions. Weight or percentage of the two fractions was not determined due to the excessive

loss of seed units that fell from the GS to the floor during the cleaning operation.

Percent filled seed was determined by hand dissecting three replicates of 10 randomly selected

seed units to determine the presence or absence of a seed. A single fraction from each lot

separated by an ASC served as a control. Four replications of 25 seed units were randomly

selected from each fraction and control, and planted in 17.5 cm x 13.3 cm x 5.9 cm containers

filled with a commercial potting medium. Containers were placed in a cooler maintained at 5° C

with no humidity control on 15 April 1997 for cold-moist stratification. Containers were watered

regularly to keep potting medium moistened.

Containers were removed from the cooler and placed in a greenhouse on 27 May 1997.

Germination counts were made 7, 14, and 21 days after placement in the greenhouse. Total

germination was determined by summing germination counts at the end of 21 days.

Filled seed and germination percentages by fraction and lot were subjected to an analysis of

variance procedure in MSTAT-C (Michigan State Univ. 1988) and significant means were

determined by least significant difference (LSD) at P<0.05 (Gomez and Gomez 1984).

Results

There was variability between lots in the percentage of seed units contained in each fraction from

the AFA (Table 1). Fractions one and two, which contained the heaviest seed units, accounted

for 37, 28 and 40% of the seed in lots A, B, and C, respectively. Light seed units and inert matter,

contained in fractions three and four, accounted for 60% or more of the lots. Differences in

percentage of seed units in each fraction indicate that an AFA has the capability to make discreet

separations between seed components not obtainable with an ASC.

Table 1. Percent seed units accounted for in each lot by fraction as determined by AFA.

 Lot

Fraction A B C

 --------------------------------%------------------------------

1 20 11 20

2 17 17 20

3 35 35 30

4 28 37 30

Seed fill of fractions by lot and cleaning technique was defined by determining the presence or

absence of a seed. Fractions one and two of lot A, B and C separated by the AFA, and fraction

one of lot C separated by the GS, had significantly increased seed fill compared to the other

fractions and control (Table 2). This indicates that the heaviest seed units associated with these

fractions contained a filled seed determined to be of good quality based on size and visual

appearance. Fraction three from the AFA was determined to have a higher percent fill than

fraction four and the control. Compared to the control, fractions one and two in lot A, B, and C

from the AFA were found to increase germination potential 44, 67 and 61%, respectively.

Fraction one from the GS increased germination potential 67% when compared to the control.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

119

Ahring and Franks (1968) reported that a South Dakota Seed Blower increased germination

potential 73 to 95%.

Percent germination for each fraction by lot and cleaning technique is presented in Table 3.

Percent germination of fractions one and two of lot A and B separated by the AFA was found to

be significantly higher than fractions three and four. Germination percentages of fractions one

and two of lot A were also significantly higher than the control. Germination of fraction one from

the GS was significantly higher than fraction two and the control. Typically the first fractions had

the highest germination percentages because they had a higher seed fill and thus a greater

germination potential. Although fraction three from the AFA contained a reasonably high

percentage of filled seed this germination potential was not reflected in the actual germination

percentages.

Table 2. Percent seed fill by lot and fraction for two cleaning techniques.

 AFA GS

Lot

Fraction A B C C

----------------------------------------%-----------------------------------

1 93 90 87 90

2 90 90 80 30

3 57 73 43 --

4 10 20 20 --

Control 47 23 23 23

LSD (0.05) 22 12 25 30

Low germination percentages for fractions with high germination potential could be explained by

seed dormancy that was not overcome by stratification (Anderson 1990) or by lesser quality of

seed than was visually estimated. Possibly a higher germination rate could have been obtained if

the test had been extended beyond 21 days.

Table 3. Percent germination by lot and fraction for two cleaning techniques.

 AFA GS

Lot

Fraction A B C C

------------------------------------------%-------------------------------------

1 43 21 24 48

2 35 29 25 15

3 15 15 18 --

4 3 3 3 --

Control 22 22 16 22

LSD (0.05) 12 12 10 13

Conclusions

Results show that seed quality of lots used in this study was improved with these seed cleaning

techniques. Fractions one and two from the AFA and fraction one from the GS contained the

highest seed quality. Fraction four and most likely fraction three from AFA can be discarded

during the cleaning operation because they may contribute few germinable seed. However,

examination of several seed units for seed fill will determine whether the third fraction is

discarded or retained.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

120

Potential implications of such cleaning techniques include improving uniformity of stands, pricing

of lots based on seed quality and selecting for seedling vigor. Seed companies upgrading seed

cleaning equipment to improve quality of eastern gamagrass seed may want to consider an AFA

as opposed to a GS due to reduced equipment costs. Based on preliminary results from this test,

the GS may have the potential to better separate complete seed units from incomplete seed units

but additional testing will be needed to verify this observation.

References

Ahring, R. M. and H. Franks. 1968. Establishment of eastern gamagrass from seed and

vegetative propagation. J. Range Manage. 21:27-30.

Anderson, R. C. 1990. Aspects of the seed biology of eastern gamagrass. Eastern Gamagrass

Conference Proceedings: 1989 January 23-25: The Kerr Center for Sustainable Agriculture,

Poteau, OK. pp.5-9.

Ball, D. M., C. S. Hoveland and G. D. Lacefield. 1991. Southern forages. Potash and

Phosphate Institution, Atlanta, GA.

Dewald. C., J. Henry, S. Bruckerhoff, J. Ritchie, D. Shepard, S. Dabney, J. Douglas, and D.

Wolfe. 1996. Guidelines for the establishing of warm season grass hedge for erosion control. J.

Soil and Water Conserv. 51(1): 16-20.

Galinat, W. C. 1956. Evolution leading to the formation of the cupulate fruitcase in American

Maydae, Bot. Mus. Leafl. Harvard Univ. 17:217-239.

Gomez, K. A. and A. A. Gomez. 1984. Statistical procedures for agricultural research. 2nd ed.

John Wiley and Sons, Inc., NY

Michigan State Univ. 1988. MSTAT-C Microcomputer Statistical Program.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

121

Clipping Effect on Yield and Quality of Eastern Gamagrass, Switchgrass,

and Bermudagrass

Scott Edwards1, Joel Douglas1 and Herby Bloodworth2

In the southeastern United States, forage producers have relied on the introduced species

bermudagrass [Cynodon dactylon (L.) Pers.] as a major component in their forage programs (Ball

et. al 1991). Numerous cultivars have been released through plant breeding and selection to

increase forage production and quality (USDA 1994). Bermudagrass should be harvested every

4 to 5 weeks to maintain optimum quality. The stage of maturity at harvest influences the

palatability, crude protein content, and especially the digestible energy level. Forage quality

deteriorates rapidly with advancing maturity even though yield will continue to increase (Ball et. al

1991).

Eastern gamagrass [Tripsacum dactyloides (L.) L.] and switchgrass [Panicum virgatum L.], both

perennial warm-season grasses native to the southeastern United States, have potential as

forage crops. Eastern gamagrass is adapted from Massachusetts to Michigan, Iowa and

Nebraska, south to Florida and Texas. Switchgrass has an even larger distribution from Maine to

North Dakota and Wyoming, south to Florida, Arizona and Mexico (Hitchcock 1951).

The increased demand for native forage species for summer grazing (Burns et al. 1992), hay

production (Hall et al. 1982) and silage (Brejda et al. 1994) have resulted in many advances in

seed production, seed quality and stand establishment techniques. However, limited information

is available on production potential of native grasses under management conditions used for

introduced species (i.e., frequent clipping). The objective of this study was to evaluate clipping

effects on yield and quality of eastern gamagrass, switchgrass, and bermudagrass.

Methods

The study was conducted over a 3-year period from 1996 to 1998 at the USDA-NRCS-Jamie L.

Whitten Plant Materials Center near Coffeeville, MS, on an Oaklimeter silt loam (Coarse-silty,

mixed, thermic Fluvaquentic Dystrochrepts). Plots were established from transplants and sprigs

and allowed to grow for 2 years before clipping treatments were introduced in May 1996.

During the establishment phase, 60 lbs N, 26 lbs P, and 36 lbs K were applied. All species were

burned each spring prior to green-up. Thirty days after green-up all plots received 60 lbs N, 39

lbs P, and 48 lbs K. After initial harvest, 180 lb N and 120 lb K were applied in split applications.

Study design was a split plot in a randomized complete block with 5 replications. Plots were split

by 30 days and 45 days clipping frequency into 10 by 20-ft plots.

Bermudagrass and switchgrass were harvested from a 3-ft by 20-ft strip in each plot at a 4 inch

cutting height using a sickle bar mower. Five eastern gamagrass plants were harvested from

each plot to a 4-inch cutting height with a hand held sickle bar trimmer. Harvested material was

weighed green in the field before a subsample was collected from each plot. Dry matter content

was determined by drying sample in a forced air oven at 55°C for 16 hours. In 1996, 30 day plots

were harvested 14 June, 15 July and 12 August; 45 day plots were harvested 28 June and 12

August. In 1997, 30 day plots were harvested 14 May, 19 June, 18 July and 18 August; 45 day

plots 19 May, 30 June, and 11 August. In 1998, 30 day plots were harvested 22 May, 18 June,

24 July and 3 September; 45 day plots 22 May, 30 June, and 25 August. Precipitation was

recorded on-site at the PMC for each year of the study (Table 1).

 

1

USDA-Natural Resources Conservation Service, Jamie L. Whitten Plant Materials Center, 2533

Co. Rd. 65, Coffeeville, Mississippi 38922; and 2

USDA-NRCS-RASP, P.O. Box 2890 Room 5210-

S, 14th and Independence Ave., Washington D.C. 20013.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

122

Table 1. Growing season precipitation totals for 1996 – 1998 and 20

year average, Coffeeville, Mississippi.

Precipitation

Month 1996 1997 1998 20 yr avg.

---------------------------inches------------------------------------

March 5.20 7.83 6.57 5.75

April 5.94 3.15 5.59 5.47

May 3.90 7.17 4.53 5.75

June 11.77 12.32 1.97 4.84

July 4.80 4.09 4.09 4.33

August 3.50 3.15 3.62 3.27

September 7.52 5.59 0.28 4.17

Total 42.64 43.31 26.65 33.58

Harvested material was weighed green in the field and random samples collected for dry matter

(DM) yield, %N, ADF, NDF. Samples were dried at 55°C for 16 hours. Percent N was

determined from Kjeldahl N digest using flow injection analysis on a Lachat Quick Chem

Automated Ion Analyzer (Lachat Instruments, Milwaukee, WI). Acid detergent fiber and NDF

were analyzed with an ANKOM200/220 Fiber Analyzer (Cherney et al. 1997). Data was subjected

to analysis of variance in SAS (v 6.12, (1996) SAS Institute Inc., Cary, NC). Duncan’s multiple

range test (DMRT) at the 5% level of probability separated significant differences between

means.

Table 2. Influence of clipping frequency on season total dry matter yield of

3 warm season grasses, 1996-1998, Coffeeville, Mississippi.

Year

Frequency 1996 1997 1998 Mean

-----------------------------------Bermudagrass--------------------------------

 --------------------------------lbs/ acre-------------------------------

30 day 11561 10221 10542 10775

45 day 11092 7905 10860 9952

LSD (0.05) NS* 1602 NS 693

---------------------------------------Eastern gamagrass---------------------------

30 day 12494 13123 3707 9775

45 day 10361 14652 12329 12447

LSD (0.05) NS NS 2235 2517

-----------------------------------Switchgrass-----------------------------

30 day 5681 5675 8594 6650

45 day 3130 7914 12300 7781

LSD (0.05) 989 1915 1297 933

* Not significant
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

123

Results

There was a significant year x frequency x species interaction, therefore each frequency was

analyzed separately. Bermudagrass produced relatively consistent yields each year for both

clipping frequencies with no differences in 1996 and 1998 (Table 2). These bermudagrass yields

agree with Fisher and Caldwell (1958) but are higher than 4 year average yield for ‘Tifton 44’

reported by Hearn (1999).

Eastern gamagrass responded early to a 30 day frequency but decreased 71% to 3707 lb/acre in

1998 (Table 3). In 1998, eastern gamagrass clipped on 30 day was slow to recover from winter

dormancy and excessive weed competition became a problem as the stand declined under the

frequent clipping regime. Brakie (1998) reported that a 30 day clipping frequency weakened

plants of southern ecotypes of eastern gamagrass in eastern Texas. Kinsinger and Hopkins

(1961) found that frequent defoliation in big bluestem [Andropogon gerardii Vitman] and western

wheatgrass [Pascopyrum smithii (Rydb.) A. Love] depleted root reserves. These food reserves

are important for growth and regrowth following dormancy, defoliation, and other stressful

conditions (Sosebee and Wiebe 1971).

Brejda (1997) reported significant variation in eastern gamagrass forage yield between years

because of wide variation in growing season precipitation amounts. In this study, it appears that

clipping frequency had more of an effect on yield for eastern gamagrass than precipitation.

During this study precipitation received during the growing season was more than 21% above the

20 year average in 1996 and 23% above average in 1997. In 1998, growing season precipitation

was 21% below the 20 year average. During 1998, with limited precipitation, there was no

significant difference in yield for 45 day plots as compared to 1996 and 1997. Eastern

gamagrass yields reported in this study for 45 day clipping frequency are consistent with yields

reported by Brejda (1997) but are lower than those reported by Brakie (1998).

Table 3. Season total dry matter yield comparison of 3 warm season grasses clipped

on 30 and 45 day frequency, 1996 – 1998, Coffeeville, Mississippi.

Year Bermudagrass Eastern

gamagrass

Switchgrass LSD (0.05)

 --------------------------------------30 day Clipping Frequency----------------------------------------

--------------------------------------lbs / acre---------------------------------------

1996 11561 12494 5682 1983

1997 10221 13123 5675 2560

1998 10541 3707 8597 1214

LSD (0.05) 1065 3088 1136

 -------------------------------------------45 day Clipping Frequency-------------------------------

-----------------------------------------lbs / acre---------------------------------------

1996 11092 10361 3130 1377

1997 7905 14652 7914 3654

1998 10860 12329 12300 NS

LSD (0.05) 1381 NS* 1573

* Not significant

Bermudagrass and eastern gamagrass produced significantly higher yields than switchgrass in

1996 and 1997 when clipped on 30 days. In 1998, there was a significant increase in switchgrass

yield. This is somewhat misleading because over half of the season total yield for 1998 30 day
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

124

clipping frequency was produced in the third cutting (data not shown). Switchgrass clipped on 30

day began to show signs of decline similar to the eastern gamagrass with increased weed

competition following winter dormancy which severely limited yield in the first and second cutting.

Beaty and Powell (1975) reported that switchgrass yield and stand decreased under frequent

defoliation resulting in an increase in weed growth.

Switchgrass yields increased significantly each year under 45 day clipping frequency. There was

a 9170 lbs/acre increase from 1996 to 1998. In 1998, there was no significant difference between

species clipped on 45 day. Switchgrass yields reported in this study are 3 times larger than those

reported by Beaty and Powell (1975).

There were significant differences in crude protein, ADF and NDF for species clipped on a 30 day

frequency (Table 4). Percent crude protein content ranged from 6 to 11% in bermudagrass, 8 to

12% in eastern gamagrass and 7 to 13% in switchgrass. Crude protein contents for eastern

gamagrass are in agreement with Brakie (1998). Protein content increased with each cutting in

all three years peaking in the third or fourth cutting except in 1998. The highest crude protein

content was in the 1998 second cutting during an extremely low precipitation period. Kamstra

(1973) and Perry and Baltensperger (1979) reported that higher crude protein levels in

switchgrass during drought years are associated with a higher leaf to stem ratio.

Table 4. Quality estimates by cutting and species for 30 day clipping frequency in 1996 –

1998, Coffeeville, Mississippi.

Species % Protein % ADF % NDF

------Cutting-------- -----Cutting--------- -----------Cutting------

12 3 4 1 2 3 4 1 2 3 4

------------------------------------------1996--------------------------------------------

Bermudagrass 8 9 8 10 38 33 37 36 72 71 72 71

Eastern

gamagrass

10 10 10 12 41 38 39 37 67 69 67 67

Switchgrass 10 9 7 9 34 34 38 36 71 69 69 66

------------------------------------------1997---------------------------------------------

Bermudagrass 6 12 10 11 33 34 35 33 72 70 70 70

Eastern

gamagrass

10 8 12 12 37 38 38 38 69 70 68 67

Switchgrass 10 8 12 12 34 33 35 35 67 70 66 65

------------------------------------------1998---------------------------------------------

Bermudagrass 9 11 9 8 38 35 38 40 74 71 71 70

Eastern

gamagrass

9 12 10 N/A* 36 36 38 N/A 67 66 68 N/A

Switchgrass 8 13 10 N/A 37 34 38 N/A 68 65 67 N/A

LSD (0.05) for differences in species and cutting for Protein = 1.5

LSD (0.05) for differences in species and cutting for ADF = 2.0

LSD (0.05) for differences in species and cutting for NDF = 2.0

* N/A = Eastern gamagrass and Switchgrass were only clipped three times in 1998.

Percent ADF ranged from 33 to 40% in bermudagrass which was significantly lower than eastern

gamagrass (36 to 41%) in all cuttings in 1996 and 1997. In 1998, there was no significant

difference in %ADF. Eastern gamagrass and switchgrass had significantly lower %NDF per

cutting as compared to bermudagrass for all years on a 30 day clipping frequency.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

125

In 1997, bermudagrass was only clipped twice on a 45 day clipping frequency. Bermudagrass

did not respond well to a late 45 day harvest in 1996. Bermudagrass clipped on 45 day produced

lower % crude protein than both eastern gamagrass and switchgrass (Table 5). Protein levels

remained more consistent across cuttings for eastern gamagrass and switchgrass unlike the 30

day frequency ranging from 6 to 11% and 6 to 10% respectively.

There was no significant difference in %ADF across cuttings or species in 1998 on a 45 day

cutting frequency. Percent NDF also remained constant from first to last cutting each year with

no significant difference within species.

Table 5. Quality estimates by cutting and species for 45 day clipping frequency in

1996 – 1998, Coffeeville, Mississippi.

Species % Protein % ADF % NDF

------Cutting------ ------Cutting------ -----Cutting-------

12 3 1 2 3 1 2 3

---------------------------------1996----------------------------------

Bermudagrass 8 6 7 37 38 38 72 74 72

Eastern

gamagrass

10 6 9 37 41 40 71 70 70

Switchgrass 10 6 7 33 40 38 71 71 68

---------------------------------1997----------------------------------

Bermudagrass 5 6 N/A* 35 38 N/A 74 74 N/A

Eastern

gamagrass

11 10 10 38 40 39 69 72 68

Switchgrass 10 8 8 34 36 39 67 71 70

---------------------------------1998----------------------------------

Bermudagrass 9 9 7 37 38 39 75 73 71

Eastern

gamagrass

10 10 10 37 38 38 68 68 70

Switchgrass 8 10 7 36 37 38 68 68 65

LSD (0.05) for differences in species and cutting for Protein = 1.5

LSD (0.05) for differences in species and cutting for ADF = 2.5

LSD (0.05) for differences in species and cutting for NDF = 4.0

* N/A = Bermudagrass was only clipped twice in 1997.

Conclusions

A 45 day clipping frequency typically represents two to three harvests per growing season in the

lower southern states, but is greatly influenced by moisture and length of growing season.

Eastern gamagrass clipped on 45 day had a 3 year average dry matter yield of 12 447 lb/acre

with no significant variation between years. Bermudagrass clipped on 30 day had one more

clipping per year but only had a 3 year average dry matter yield of 10 775. Clipping on a 30 day

frequency reduced stands allowing weeds to invade both eastern gamagrass and switchgrass. A

45 day clipping frequency appears to be more suited for eastern gamagrass, as indicated by the

sustained yield across years.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

126

References

Ball, D.M. and C. S. Hoveland, and G. D. Lacefield. 1991. Southern Forages.

Potash and Phosphate Institute, Norcross, GA.

Beaty E. R., and J.D. Powell. 1975. Response of switchgrass (Panicum virgatum L.) to clipping

frequency. J. Range Manage. 29(2):132-135.

Brakie, M.R. 1998. Yield and quality of eastern gamagrass selection as affected by clipping

interval and N rates. MS Thesis. SFA State Univ., Nacogdoches, TX.

Brejda, J.J., J.R. Brown, J.M. Asplund, T.E. Lorenz, J.L. Reid, and J. Henry. 1994. Eastern

gamagrass silage fermentation characteristics and quality under different nitrogen rates. J. Prod.

Agric. 7:477-482.

Burns, J.C., D.S. Fisher, K.R. Pond, and D.H. Timothy. 1992. Diet characteristics, digesta

kinetics, and dry matter intake of steers grazing eastern gamagrass. J. Anim. Sci. 70:1251-1261.

Fisher, F. L. and Caldwell, A. G. Caldwell. 1958. The effects of continued use of heavy rates of

fertilizers on forage production and quality of coastal bermudagrass. Texas Agr. Exp. Sta. Tech.

Article No. 2935.

Hall, K.E., J.R. George, and R.R. Riedl. 1982. Dry matter yields of switchgrass, big bluestem,

and Indiangrass with N fertilization. Agron. J. 74: 47-51.

Hearn, R. A. 1999. Mississippi forage crop, variety trials. MS. Agric. Exp. Stn. Bull 356 Ag

Communications, Mississippi State University Division Ag, Vet Med.

Hitchcock, A.S. 1951. Manual of the grasses of the United States. USDA Misc. Publ. 200. U.S.

Department of Agriculture.

Kamstra, L. D. 1973. Seasonal changes in quality of some important range grasses. J. Range

Manage. 26:289-291.

Kinsinger, F.E. and H. H. Hopkins. 1961. Carbohydrate content of underground parts of grasses

as affected by clipping. J. of Range Manage. 14(6):9-13.

Perry, L. J. and D. D. Baltensperger. 1979. Leaf and stem yields and forage quality of three N

fertilized warm season grasses. Agron. J. 71: 355-358.

Sosebee, R .E. and H. H. Wiebe. 1971. Effect of water stress and clipping on photosynthate

translocation in two grasses. Agron. J. 63: 14-17.

U.S. Department of Agriculture. 1994. Grass varieties in the United States. USDA Handbook

No. 170.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

127

New and Upcoming Native Grass Releases from

the Eastern US Plant Materials Centers

John Englert1

Introduction

In recent years there has been an increased emphasis in using native plants for planting projects

ranging from ecosystem restoration to USDA conservation programs to home landscaping. In the

eastern US many of these native species are often available in limited quantities or only as

vegetative propagules, which makes large planting projects expensive or difficult. The eight

eastern US Plant Materials Centers (PMC) of the USDA-NRCS Plant Materials Program are

currently developing nearly 50 new native grass releases for the eastern US. These new

releases have their origin in the eastern US, and will serve important roles in conservation

programs and restoration activities in the region.

Meeting the Challenge

Current needs for native plants in restoration or conservation projects often calls for local-source

ecotypes. Depending on the user’s concept of “native” and the type of planting being conducted,

“local-source” plant materials can be defined as material found from several miles to several

hundred miles from the location of the planting site. For small projects, it is often possible to find

very local materials either through collection or small-scale production. For larger projects

covering hundreds or thousands of acres, plant materials are usually purchased from commercial

nurseries. Native grasses in the East are often expensive, in limited quantities as seed, or

impossible to find, thus making it necessary to develop and release new plants for the eastern

US. Plant Materials Centers seek to find a middle ground when developing new native grass

releases. Releases must have the potential to be viable in the commercial market in order to

meet the needs of conservation activities supported by USDA. To accomplish this, PMCs

carefully assemble and select plants to meet identified needs and assess the viability of the

proposed release for commercial production.

The Development of New Releases

There are four types of plant releases defined by the Association of Official Seed Certifying

Agencies (AOSCA). The traditional type of release that most people are familiar with is the

cultivar. Cultivars are the most developed release material. The material is usually genetically

uniform, and the performance and adaptation of the cultivar has been well documented. Tested

and Selected types have had some genetic selection and the materials may have undergone

varying degrees of testing on planting sites. The material usually has greater genetic diversity

than the cultivar, but the performance and adaptation of tested and selected classes of releases

may not be fully investigated. Source-identified types are typically “straight from the field” and

may have the most genetic diversity within the collection. There is usually no information

developed on the performance and adaptation of source-identified releases beyond what can be

inferred from the collection site.

When ecological restoration or enhancement is the goal of a planting project, locally collected,

source-identified plant materials are usually preferred because they are assumed to have a wide

variety of genetic material which is adapted to the area around the planting site. For most

conservation work, and in particular the stabilization of “highly stressed” critical areas, using

source-identified class plant materials may be risky due to the lack of performance information on

the material. With critical area stabilization work, such as that done on streambanks and

 

1

 Horticulturist/PMC Manager, USDA-NRCS National Plant Materials Center, Bldg. 509, BARCEast, Beltsville, MD 20705, phone: 301-504-8175; e-mail: jenglert@md.usda.gov
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

128

shorelines, it is necessary to stabilize the site so that excessive erosion does not occur. In this

case, cultivars which are specifically adapted to such sites are often the best suited. Similar

situations may occur in other conservation activities. In the case of plant materials used for

forage, cultivars specifically selected for improved nutrition and regrowth may outperform local

unselected materials. “Middle ground” type projects include those for buffers and wildlife

plantings. Usually it is desirable to know that the plant materials are going to achieve the desired

results, i.e. produce food for wildlife or provide a vegetative buffer between developed land and a

wetland, but it is often not necessary or desirable to have highly selected materials or to know the

entire range of performance and adaptation. In this case, selected and tested class releases are

often best suited. The bottom line is that the person or office planning the planting needs to

decide what the objective is and which plant materials are best suited to meet that objective.

One of the major challenges in using native grasses is finding local ecotypes, which are native to

the eastern, US. Many of the warm-season grass cultivars now used in the East are from midwestern sources. Finding local ecotype materials for conservation activities can be especially

challenging. There are very few species of cool-season native grasses available from

commercial sources. PMCs in the east are currently making collections of both cool-season and

warm-season native grass species. Materials that are currently being selected or developed are

often collected from areas over 100-300 miles in diameter, and the intended area of use is usually

similar in size to the original collection area. In this way we are able to release a plant that should

have enough market potential to be a viable product to commercial growers, but yet retain the

native germplasm of the intended area of use. Depending on the class of release, the plant

materials have undergone different levels of selection and testing appropriate to the intended use

of the material.

Plant Materials Currently Being Evaluated for Release

There are currently about 50 new assemblies for potential release under evaluation (Table 1).

These assemblies range in development from source-identified to cultivar type releases.

Anticipated dates of release and availability on the commercial market range from 2000 to 2006.

Table 1 briefly describes these species under evaluation and details anticipated uses and area of

adaptation for these species. For more information on particular materials, please contact the

PMC listed under the “Releasing PMC” column in Table 1. A listing of contact information for

these PMCs is located in Table 2.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

129

Table 1. Listing of native grasses under evaluation.Scientific Name/Common Name

Projected Year ofRelease

CollectionLocation

ReleasingPMC

Type ofRelease

Known or PoteUses

Warm-season Grass SpeciesAmphicarpum muhlenbergianum(Schult.) Hitchc. /blue maidencane

2001-2002 Florida FLPMC Selected forage, wetland

restoration, imprwater quality

Andropogon gerardii Vitman / bigbluestem

2002-2003 Great Lakes

states

MIPMC Cultivar Rotational grazin

systems

Andropogon gerardii Vitman / big

bluestem

2001-2002 lower MI

peninsula

MIPMC Sourceidentified Cons. Reserve P

other conservati

Andropogon gerardii Vitman / big

bluestem

2002-2003 Mid-Atlantic

US

NJPMC Selected general conserv

use

Andropogon glomeratus(Walter)

Britton et al. var. glaucopsis/

chalky bluestem

2002-2003 Florida FLPMC Selected forage, wetland

restoration, imprwater quality

Calamovilfa longifolia (Hook.)

Scribn. /

prairie sandreed

2002-2003 Great Lakes

coastal areas

MIPMC Tested dune stabilizatio

Coelorachis (Manisuris) cylindrica/Carolina jointtail grass

2002-2003 Southern MidAtlantic

coastline

NJPMC Selected general conserv

use

Panicum anceps Michx. /Beaked panicum

2002-2003 Mid-Atlantic

Coastal Plain

NJPMC selected tolerant to hot dr

high pH, and higmetals

Panicum virgatum L./’Carthage’ switchgrass

2000 Carthage, NC NJPMC cultivar wildlife habitat, b

pastures, and as component of naplant mixes

Panicum virgatum L./Switchgrass

2002 Brooklyn, NY NJPMC tested dune/coastal

stabilization, critstabilization

Panicum virgatum L./Switchgrass

2001-2002 lower MI

peninsula

MIPMC sourceidentified Conservation Re

Program, otherconservation use
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

130

Scientific Name/Common Name

Projected Year ofRelease

CollectionLocation

ReleasingPMC

Type ofRelease

Known or PoteUses

Panicum virgatum L./Switchgrass

2002 northern MidAtlantic

Piedmont

MDPMC selected General conserv

use

Panicum virgatum L./Switchgrass

2003-2004 Mid-Atlantic

US

NJPMC selected/

tested

Saline-tolerant; friparian areastabilization in swater areas

Schizachyrium scoparium (Michx.)

Nash /

Little bluestem

2001-2002 lower MI

peninsula

MIPMC sourceidentified Conservation Re

Program, otherconservation use

Schizachyrium scoparium (Michx.)

Nash /

Little bluestem

2002 Mid-Atlantic

US

NJPMC selected General conserv

use

Schizachyrium scoparium var.littoralis (Nash) Gandhi & Smeins /Coastal little bluestem

2002 coastal MidAtlantic NJPMC selected General conserv

use 

Sorghastrum secundum (Elliott)

Nash /

Lopsided Indiangrass

2002-2003 Florida FLPMC selected wildlife habitat,

rangeland impronative plant comrestoration

Sorghastrum nutans (L.) Nash /Indiangrass

2000 composite NJ,

DE, MD, VA

MDPMC selected general conserv

use, wildlife hab

Sorghastrum nutans (L.) Nash /Indiangrass

2000-2001 GA, AL GAPMC cultivar forage, grazing 

Sorghastrum nutans (L.) Nash /Indiangrass

2001-2002 lower MI

peninsula

MIPMC sourceidentified Conservation Re

Program, otherconservation use

Sorghastrum nutans (L.) Nash /Indiangrass

2003-2004 composite VA,

NC

NJPMC selected/

tested

general conservuse, grazing

Sorghastrum nutans (L.) Nash /Indiangrass

2003-2004 composite NY,

PA, MD

NYPMC tested/

cultivar

wildlife habitat, gconservation use

Spartina pectinata Link/Prairie cordgrass

2004 coastal MidAtlantic NJPMC tested stabilization, imp

water quality 
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

131

Scientific Name/Common Name

Projected Year ofRelease

CollectionLocation

ReleasingPMC

Type ofRelease

Known or PoteUses

Spartina pectinata Link/prairie cordgrass

2002-2003 Long Island,

NY

NYPMC selected freshwater shore

stabilization, critCRP, wet sites, areas

Spartina pectinata Link/prairie cordgrass

2002-2003 NH, MA NYPMC selected freshwater shore

stabilization, critCRP, wet sites, areas

Tripsacum dactyloides (L.) L./eastern gamagrass

2002-2003 Montgomery

Co., TN

MSPMC,GAPMC

cultivar Tetraploid; for fo

general conservuse

Tripsacum dactyloides (L.) L /eastern gamagrass

2001-2002 Florida FLPMC cultivar forage, wildlife, g

conservation

Tripsacum dactyloides (L.) L /eastern gamagrass

2001-2002 Florida FLPMC selected Foliage has bluis

xeriscaping, buff

Tripsacum dactyloides (L.) L /eastern gamagrass

2001-2002 Beltsville, MD NYPMC tested/

cultivar

Tetraploid; higheproduction than 

Uniola paniculata L. /sea oats

2000 Mid-Atlantic

coastline

NJPMC tested dune stabilizatio

diversity, generaconservation use

Cool-season grass speciesBromus pubescens Muhl. ex Willd.

/

Canada brome

2002-2004 Great Lakes

region

MIPMC selected general conserv

use, pasture

Bromus pubescens Muhl. ex Willd.

/

Canada brome

2002-2004 Mid-Atlantic

Piedmontregion

MDPMC selected general conserv

use, pasture

Calamagrostis canadensis (Michx.)

P. Beauv. /

Canada bluejoint

2002-2004 Great Lakes

region

MIPMC general conserv

use

Calamagrostis canadensis (Michx.)

P. Beauv. /

Canada bluejoint

2002-2004 upper MidAtlantic NJPMC selected general conserv

use 
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

132

Scientific Name/Common Name

Projected Year ofRelease

CollectionLocation

ReleasingPMC

Type ofRelease

Known or PoteUses

Calamagrostis canadensis (Michx.)

P. Beauv. /

Canada bluejoint

2002-2004 Northeast NYPMC selected/

tested

general conservuse

Cinna arundinacea L. /stout woodreed

2002-2004 Mid-Atlantic

Piedmontregion

MDPMC selected general conserv

use

Cinna arundinacea L. / stout

woodreed

2002-2004 Northeast NYPMC selected general conserv

use

Danthonia spicata (L.) P. Beauv.

ex Roem. & Schult. /

poverty oatgrass

2002-2004 Great Lakes

region

MIPMC selected general conserv

use

Danthonia spicata (L.) P. Beauv.

ex Roem. & Schult. /

poverty oatgrass

2002-2004 Northeast NYPMC selected general conserv

use

Deschampsia flexuosa (L.) Trin. /crinkled hairgrass

2002-2004 Mid-Atlantic NJPMC selected general conserv

use

Elymus canadensis L. / Canada

wildrye

2003-2004 Northeast NYPMC selected general conserv

use

Elymus canadensis L. /Canada

wildrye

2003-2004 Great Lakes

region

MIPMC selected general conserv

use

Elymus villosus Muhl. ex Willd. /hairy wildrye

2003-2004 Mid-Atlantic

Piedmontregion

MDPMC selected general conserv

use

Elymus virginicus L. /Virginia wildrye

2001 Mid-Atlantic

Piedmontregion

MDPMC selected general conserv

use

Elymus virginicus L. /Virginia wildrye

2002-2003 coastal NJ,

VA, NC

NJPMC selected stabilization of b

areas in the Mid

Elymus virginicus L. /Virginia wildrye

2001-2003 Great Lakes

region

MIPMC selected general conserv

use

Hordeum pusillum Nutt. /little

barley

2002-2003 Mid-Atlantic

Piedmontregion, NC

MDPMC winter annual co
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

133

Scientific Name/Common Name

Projected Year ofRelease

CollectionLocation

ReleasingPMC

Type ofRelease

Known or PoteUses

Hystrix patula Moench/bottlebrush grass

2001-2002 Mid-Atlantic

Piedmontregion

MDPMC selected general conserv

use

Hystrix patula Moench/bottlebrush grass

2002-2003 Great Lakes

region

MIPMC selected general conserv

use

Koeleria macrantha (Ledeb.)

Schult.) /

Junegrass

2002-2004 Great Lakes

region

MIPMC selected general conserv

use
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

134

Table 2. Contact Information for eastern PMCs

Florida

Clarence Maura, Jr.; PMC Manager

USDA-NRCS Brooksville Plant Materials Center, 14119 Broad St., Brooksville, FL 34601

phone: 352-796-9600; fax: 352-799-7305; e-mail: Clarence.Maura@fl.usda.gov

Georgia

Mike Owsley; PMC Manager

USDA-NRCS Jimmy Carter Plant Materials Center, 295 Morris Dr., Americus, GA 31709

phone: 912-924-4499; fax: 912-924-0013;

e-mail: Mike.Owsley@gaamericu2.fsc.usda.gov

Maryland

John M. Englert; Team Leader/Horticulturist

USDA-NRCS National Plant Materials Center, Bldg. 509, BARC-East, E. Beaver Dam Rd.,

Beltsville, MD 20705

phone: 301-504-8175; fax: 301-504-8741; e-mail: jenglert@md.usda.gov

Michigan

Tony Bush; Acting Manager/Agronomist

USDA-NRCS Rose Lake Plant Materials Center, 7472 Stoll Rd., East Lansing, MI 48823-9420

phone: 517-641-6300; fax: 517-641-4397; e-mail: tbush@mi.nrcs.usda.gov

Mississippi

Joel L. Douglas; PMC Manager

USDA-NRCS Jamie L. Whitten Plant Materials Center, 2533 County Road 65, Coffeeville, MS

38922-2652

phone: 601-675-2588; fax: 601-675-2369; e-mail: jdouglas@ms.nrcs.usda.gov

New Jersey

William Skaradek; PMC Manager

USDA-NRCS Cape May Plant Materials Center, 1536 Route 9 North, Cape May Court House, NJ

08210

phone: 609-465-5901; fax: 609-465-9284; e-mail: wskaradek@nj.nrcs.usda.gov

New York

Martin van der Grinten; PMC Manager

USDA-NRCS Big Flats Plant Materials Center, RD #1, Route 352, Box 360 A, Corning, NY

14830-0360

phone: 607-562-8404; fax: 607-562-8516; e-mail: martin.vandergrinten@ny.usda.gov

West Virginia

John Vandevender; PMC Manager

USDA-NRCS Alderson Plant Materials Center, PO Box 390, Alderson, WV 24910

phone: 304-256-2879; fax: 304-256-2936; e-mail: John.Vandevender@wv.usda.gov
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

135

Is Growing Native Seeds for Me?

The Who, What, When, Where and Why

Calvin L. Ernst1

Summary

1. Are you one who has the resources and desire to be a native grass producer?

2. Do you know what should be grown?

3. When do you start growing native grasses and when will there be a return for growing seed?

4. Where are the best locations to grow native seeds and does that ‘where’ limit the available

species that can be grown?

5. Why should one be willing to grow native species?

Calvin Ernst, with his wife Marcia and three children, own and operate a seed production and

marketing business known as Ernst Conservation Seeds.

The northwestern Pennsylvania farm consists of 1,600 acres of seed production for conservation

and restoration use. About 30 full time employees are engaged in all aspects of growing and

marketing conservation seed.

Our seed is marketed for environmental restoration of wetlands, roadsides, surface mining,

wildlife habitat and landfills.

Our principal market is in the eastern United States and Canada through direct sales and through

a network of seed distributors.

 

1

 General Partner, Ernst Conservation Seeds, Meadville, Pennsylvania
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

136

Extending the Grazing Season in Southeast Pennsylvania

Cheryl A. Fairbairn, G.A. Jung, and L.D. Hoffman1

Pasture is the cornerstone of a successful beef cattle operation. Green grass supplies most of

the essential nutrients needed by a cow for all stages of her reproductive cycle. Desired goals of

pasture production are:

1. To produce higher yields of palatable and nutritious forage.

2. To extend the grazing season from as early in the spring to as late in the Fall as possible.

3. To provide a fairly uniform supply of feed throughout the entire season.

No one plant species embodies all the desirable characteristics necessary to meet the above

goals. None will grow year round or during extremely cold or dry weather. Each species has a

period of peak growth which must be conserved for periods of little growth. Cattlemen must

utilize various grass species and a combination of permanent, rotational and temporary pastures.

Warm season grass species such as switchgrass and big bluestem fit well into the scheme of

weather patterns and pasture situations in southeastern Pennsylvania. The majority of pastures

in southeastern Pennsylvania are comprised of cool season grasses such as orchardgrass,

smooth bromegrass, timothy, and Kentucky bluegrass, which make 60 to 70 percent of their

yearly production (growth) prior to June 15. Heavy grazing of these pastures along with high

temperature and low moisture common to southeastern Pennsylvania usually results in very little

grass for grazing during July and August.

Warm season grasses such as big bluestem, Indiangrass, and switchgrass make nearly 85%

percent of their production after June 1. As temperatures reach 80°F and water stress increases,

cool season grass growth slows and at 95°F cool season grasses grow very little. As cool

season grass production slows, warm season grass production begins and continues through the

summer.

In a cow/calf operation, weaning weights are often lowered due to the lack of green forages in

July and August. At the same time cows often lose weight and milk production begins to tail off.

Producers are often forced to feed expensive hay at this time to keep weight loss at a minimum or

they graze their pastures to the ground resulting in little or no re-growth during the cool fall

months. If they didn’t feed hay in the summer, they are forced to begin feeding hay in early

September.

Because of the extreme heat and low moisture found in southeastern Pennsylvania during the

summer months, it was decided to try two warm season grass demonstration plots in Chester

County. In May of 1983, with the cooperation of the USDA ARS Pasture Research Lab,

Pennsylvania State Agronomy Department, the Natural Resource Conservation Service and the

Pennsylvania State Extension Service, two fields totaling 12 acres were seeded to switchgrass.

Both fields were no-tilled using a John Deere Power Drill and a Tye drill. Both were planted in

corn stubble. No fertilizer or lime was applied at this time. An interesting aspect of these native

grasses is that they can grow in acid soils and require less fertilizer than do cool season grasses.

They also grow well in very droughty soils as well as very wet soils.

A major drawback of the warm season grasses is their slow establishment. They are slow to

germinate and cannot withstand much competition from weeds. A herbicide program was utilized

to keep broadleaf weed competition to a minimum. Cattle were kept off the field the entire

growing season to insure adequate development of the root system. At the end of the droughty

summer, the newly planted grasses were 12 inches tall. After the first hard frost, the producers

had the option of mowing or grazing the grasses.

 

1 Pennsylvania State University and USDA-ARS, University Park, PA.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

137

In May of 1984 a grant was obtained from Allied Chemical Company to study the effect of

nitrogen fertilization on four varieties of switchgrass (Table 1). Each switchgrass variety received

zero nitrogen treatment or 50 lbs. of nitrogen using urea or 50 lbs. of nitrogen using ammonium

sulfate. Weekly growth measurements were taken along with yield and quality samples. On the

8-acre Flagg field, the first cutting of hay was taken on July 8 and 9. In order to insure proper

regrowth, an 8-inch stubble was left since the growing point of the warm season grasses was 4

feet. Some varieties stood as tall as 5 feet. Excellent regrowth occurred and the second cutting

was made on September 15. Yield production for each variety and treatment are listed in Table

1.

Table 1. Total Summer Production - Flagg Farm (Tons Acre-1)

Variety Ammonium Sulfate Urea Zero N

Blackwell 5.32 4.05 3.65

Indian 6.93 6.17 4.78

NJ 50 4.78 4.41 3.52

Pathfinder 3.83 5.00 3.11

At the Cairns Farm, the 4-acres were split into 3 equal sections with portable electric fence. Each

section allowed access to all varieties and fertilizer treatments. Cows grazed cool season

grasses from May until the first part of July. On July 8 the cows and calves were weighed and

turned into the switchgrass test field. Seven cow/calf units and three yearling heifers were turned

into one section at a time for a period of ten days. As the grasses were grazed down to an

approximate 12-inch stubble the cattle were moved. At the end of thirty days the cattle were

moved and weighed again. As at the Flagg Farm, height, yield and quality samples were taken.

Cattle were turned in when the grasses were on the average four feet tall. After thirty days on the

warm season grasses, the cattle were moved back onto rested cool season grasses and thirty

days later, they were turned back onto the first section of warm season grasses. The cattle

grazed these grasses from September 1 until September 27 and then they were again turned

back onto the cool season grasses. After the first hard frost in November, they were again turned

onto the switchgrass to graze it to the ground. The producer then moved them onto corn stubble

and began to feed hay around the end of November.

During that first grazing period, cow’s gained an average of 2.12 lbs per day with a stocking

density of 7.52 animal units (AU) per acre. Quite different from the usual cow/calf operation

where stocking density can range from 1 AU per acre to as low as 0.2 AU per acre depending on

the management of the cool season grass pastures. Usually, cows nursing calves and grazing

worn-out cool season grass pastures in July and August will lose weight and drop in their milk

production. Weaning weights are a direct result of the milking ability of the dam. Increased milk

production will result in increased weaning weights, and there is no better promoter of milk

production in cows than fresh green grass. Yield production for each variety and treatment is

listed in Table 2.

Table 2. Total Summer Production-Cairns Farm (Tons Acre-1)

Variety Ammonium Sulfate Urea Zero N

Blackwell 3.20 3.03 1.62

Indian 4.23 3.25 2.35

NJ 50 3.20 3.20 1.85

Pathfinder 3.38 2.84 1.85

Warm season grasses reduce production costs. It takes one-half as much water to produce a ton

of native warm season grass forage as it takes to produce a ton of cool season grass forage.

Native warm season grasses utilize nitrogen more efficiently and produce 2 to 3 times more
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

138

forage than cool season grasses when no commercial nitrogen is applied. They also produce

palatable and nutritious forages during the hot, dry-summer months when the cool season

grasses are relatively non-productive. With proper care they can have a stand life of 10-20 years.

The Flagg Farm, now under new ownership, still has warm season grasses existing on that site.

In summary, warm season grasses provide these benefits to the producer:

1. Extend the grazing season through the hot summer months.

2. Require little fertilization which cuts down production costs.

3. Are a great safeguard against drought.

4. Can turn less productive ground into very useable pasture.

5. Allow the producer to increase his stocking rate.

Problems of warm season grasses that limit the use to producer:

1. Slow to establish. It is very difficult for producers in southeast Pennsylvania to set

ground aside for an entire year just to get the crop established.

2. Management is a must with these grasses especially during the establishment year.

Invading cool season grasses have to be controlled. The mindset of overgrazing has to

be changed. Rotational grazing is a must for these grasses to be used properly.

3. Producers must have adequate cool season pasture acreage in order to give the warm

seasons the rest they require.

In summary, warm season grasses do have a place in cow/calf production systems in southeast

Pennsylvania. We have seen some increases in the use of warm season grasses in larger

cow/calf operations. However, the major stumbling block continues to be the establishment

problem. With continued research in this area, this problem may be overcome and an even

greater increase of warm season grass acreage may be seen in this part of the country in the

future.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

139

Albany Pine Bush Native Plant Restoration Project:

Attractive Alternatives Help Protect a Rare Ecosystem

Neil A. Gifford1

Abstract

The Albany Pine Bush is the best remaining example of an inland pitch pine - scrub oak barrens

and home to a variety of rare plants and animals (including the federally endangered Karner blue

butterfly), hundreds of common, but no less worthy species, many people, businesses and jobs.

The Albany Pine Bush Native Plant Restoration and Landscaping Project is a cooperative public

and private effort making locally derived native Pine Bush plants commercially available for

ecosystem restoration and landscaping. Landscaping with locally-derived native species

enhances the buffer between developed and adjacent protected Preserve lands, softening

development’s impacts on this globally rare ecosystem and reducing the abundance of potentially

invasive pest plants. Native grasses, wildflowers, trees, and shrubs provide a wide variety of

attractive landscape choices and are accustomed to local conditions (water, soil, and insect

pests), costing less in the long-term than many non-native alternatives. Whether landscaping

roadsides, residential or commercial sites, using native plants makes good economic and

ecological sense. Working together, goals of biodiversity conservation and sustainable and

compatible economic development can be balanced.

 

1

 Preserve Ecologist, The Nature Conservancy, Albany Pine Bush Preserve, 108 Wade Road,

Latham, NY 12110, Phone (518) 785-1800 ext. 214
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

140

Transfer of Technology on Native Grasses

Robert Glennon1

Abstract

The key to successful native grass establishment and management on a large scale is a welltrained cadre of professionals in the field to better educate, inform, and assist landowners.

Current establishment and management technology must be incorporated into all USDA

standards and specifications, Extension Service bulletins, and Game and Fish agency

publications that address the land uses or practices that may use the species. All commercial

sources of all species and cultivars must be updated at least annually and forwarded to field

personnel. Specialists must remain current on seed costs; incorporate those costs into USDA

cost share rates and Extension Service budgets, and share the information with field personnel.

Practical skills such as seed rate calculation, drill calibration, seeding depth adjustment, and

species identification and deferred grazing must be taught to field personnel. Successful use of

the technology will involve technology transfer not only to NRCS and Extension Service

employees, but employees of conservation districts, state wildlife and fish agencies, and natural

heritage agencies and organizations. Further transfer to the landowners who will be actually

establishing and managing stands must be accomplished not only with printed information, but

also with workshops, field days, tours, pasture walks, and videos.

 

1

 Ecologist, USDA, Natural Resources Conservation Service, Little Rock, Arkansas
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

141

NRCS National Practice Standard for Vegetative Barriers

Robert Glennon1

Abstract

Over the past 12 years, a group of researchers and conservation practitioners have been

developing technology on vegetative barriers (grass hedges) and comparing notes on how they

perform over a wide range of conditions. The technology is at a stage where a national practice

standard has been prepared and is posted for comment this summer. The standard includes the

usual institutional requirements for a standard: definition, purpose, condition where the practice

applies, criteria, planning considerations, operation and maintenance, and specifications and

plans. The standard is broad enough to allow the use of any herbaceous or woody plant that will

slow runoff and cause sediment to be deposited. The standard encourages the use of native

grasses and stiff-stemmed cultivars of those grasses. It presents criteria for establishment from

seed and vegetative material. Criteria for an adequate stand in terms of stems per square foot are

based on the diameter of the stem. It includes special criteria for barriers on uniform slopes,

barriers in concentrated flow areas, barriers as field borders, and barriers used to increase the

efficiency of other conservation practices.

 

1

 Ecologist, USDA, Natural Resources Conservation Service, Little Rock, Arkansas
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

142

Wildflower Seed Production at the Jamie L. Whitten Plant Materials Center

Janet M. Grabowski1

The demand is increasing for incorporating wildflowers into appropriate plantings on both public

and private lands. Wildflowers provide seasonal beauty and visual interest to the landscape.

Some may also have edible seed or act as cover to benefit various types of wildlife. Appropriate

selection and use of wildflowers can also express a sense of regional identity; for example

bluebonnets [Lupinus subcarnosus Hook.] are synonymous with spring in Texas. Use of native

species is highly recommended because they are generally not prone to encroaching into areas

in which they were not planted and will therefore present little weed potential. Wildflowers can be

ideal companion plants for native or introduced grasses on many planting sites (e.g. prairie

restorations, roadsides, and critical areas). Healthy wildflower plantings usually require minimal

care to maintain a satisfactory level of attractiveness, which makes them ideal for use in low

maintenance areas. Many state highway departments are promoting the use of wildflowers, not

only for beautification, but also from a practical standpoint in response to increasing costs

associated with mowing and restrictions on herbicide applications.

Although wildflower seed can be purchased from commercial producers, the species of interest

may not always be available in sufficient quantities to meet demands. Also, available seed may

not be adapted to specific conditions on the planting site. Seed purchased from a producer in a

different geographic region, will generally not be as well adapted as seed from a more local

source due to ecotypic differences in plant populations. Growers are not required to inform

customers of the original source of their seed, so even local producers may not be offering seed

of local ecotypes. Often seed companies will subject their plant populations to a selection or

breeding process to improve appearance or production characteristics (increase flower size, plant

size, seed set, etc.). This improvement process could decrease the chance for survival on poor

planting sites by reducing genetic diversity and potentially increasing susceptibility to insect,

disease, and environmental stresses. For these reasons, many state highway departments and

other customers are increasingly requesting local ecotypes of seed for their plantings. However,

the potential market for seed of specific ecotypes may not be large or lucrative enough to

encourage growers to initiate production. United States Department of Agriculture, Natural

Resources Conservation Service, Plant Materials Centers (PMCs) explore various ways to use

vegetation to solve conservation problems. As a part of this mission, PMCs have achieved a high

level of expertise in producing seed of many different types of plants. The Jamie L. Whitten PMC

in Coffeeville, Mississippi currently has a memorandum of understanding with the Mississippi Soil

and Water Conservation Commission to produce wildflower seed under the auspices of the

Native Wildflower Conservation Program. This program addresses an identified need in

Mississippi for locally adapted wildflower seed to be made available to local conservation districts

for use in district projects or for them to supply to landowners or to various government or

regional entities.

Methods

Wildflower species being produced for this program are listed in Table 1. Ease-of-production and

yield characteristics were major criteria used in selecting species for production. All species are

considered to be native to all or portions of the state of Mississippi, with the exception of plains

coreopsis, whose native range extends to areas just west of the state. All seed was originally

collected from sites in Mississippi. The first six species listed are in large-scale production (0.4 to

5 ha) at the PMC. The following two and the final species are adapted to specialized site

conditions and are therefore being produced in smaller quantities. Purple coneflower populations

are currently being increased for future large-scale production.

 

1

 United States Department of Agriculture, Natural Resources Conservation Service, Jamie L.

Whitten Plant Materials Center, Coffeeville, MS 38922-2652.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

143

Table 1. Wildflower species being produced at the Jamie L. Whitten PMC.

Common Name Scientific Name

Black-eyed Susan Rudbeckia hirta L.

Clasping coneflower Dracopis amplexicaulis (Vahl) Cass.

Plains coreopsis Coreopsis tinctoria Nutt.

Partridge pea Chamaecrista fasciculata (Michx.) Greene

Bur marigold Bidens aristosa (Michx.) Britton

Lyre-leaf sage Salvia lyrata L.

Swamp rose-mallow Hibiscus moscheutos subsp. lasiocarpos (Cav.) O.J. Blanchard

Cardinal flower Lobelia cardinalis L.

Purple coneflower Echinacea purpurea (L.) Moench

Meadow beauty Rhexia mariana L.

Although most of these wildflower species have a fairly high tolerance to adverse growing

conditions, they produce the greatest amount of seed when planted on appropriate sites.

Planting species on fields with the correct soil moisture regime (Table 2) is the greatest key to

success. This is why swamp rose-mallow is planted in aquatic plant production ponds and blackeyed Susan is planted on dry, hilly fields. Most of the PMC fields utilized for production of

wildflower seed are poorly suited for research purposes. All species except cardinal flower are

grown in fields with full sun exposure. Cardinal flower is grown in a somewhat shaded field,

mainly to increase available soil moisture levels. Capability to irrigate production fields is not

readily available at the PMC. Earlier attempts to grow cardinal flower in aquatic ponds (similar to

swamp rose-mallow) were unsuccessful due to intense weed pressure.

Table 2. Site information requirements for species produced.

Species Soil Moisture

Black-eyed Susan Normal/Dry

Clasping coneflower Normal/Moist

Plains coreopsis Normal/Moist

Partridge pea Normal/Dry

Bur marigold Moist

Lyre-leaf sage Normal/Dry

Swamp rose-mallow Wet/Moist

Cardinal flower Moist/Wet

Purple coneflower Normal/Dry

Meadow beauty Moist

Appropriate planting dates for each species are listed in Table 3. The majority of these species

are planted in late summer to early fall. A typical germination pattern is for seed to germinate in

the fall and for plants to overwinter in a rosette stage. If environmental conditions are not

favorable for seed to germinate in the fall it will retain viability and germinate the following spring;

however, flowering will be delayed that first year. Bur marigold is an exception; although sown in

the fall, it will not germinate until spring because its seed requires a stratification (cold-moist)

period.

Field establishment methods follow a similar pattern for all species, with the exceptions noted

below. The first step is spraying the planting site with a herbicide to control weeds several weeks

before the scheduled planting time. Usually glyphosate (Roundup Ultra) is used at a rate of

1.12 to 2.24 kg ai ha-1, (ai – active ingredient) with the higher rate used on areas with problem

perennial weeds. The field is then burned to eliminate plant residue and disked to prepare a

clean seedbed and incorporate ash deposits. PMC personnel have noticed that germination

appeared to be delayed in fields where the ash residue was not incorporated. The soil is then

packed with a cultipacker because a fluffy seedbed will result in the seed being buried too deeply

for optimum emergence. Seed is then either broadcast or drilled in rows onto planting site (Table
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

144

3). Broadcast planting is used mainly because wildflower fields will not be cultivated to control

weeds; however, broadcasting also allows for higher plant populations and greater seed

production per unit area. Cultivation will be discussed further under the topic of weed control.

The field is then cultipacked again after planting to ensure good seed-to-soil contact. A full plant

stand is generally produced in the first growing year; however, some species such as lyre-leaf

sage and occasionally black-eyed Susan require additional growing seasons for populations to

build up to an acceptable stand. To encourage stand development, fields are treated with

appropriate herbicides to control weeds, seed is not harvested, and the field is mowed after seed

set to scatter any seed produced. Many fields have remained in continuous production for close

to a decade and are still producing large quantities of seed. Fields of some species such as

black-eyed Susan are renovated or moved to new locations every few years, generally because

of weed encroachment.

Table 3. Planting information on species produced.

Species Planting Date Method

Black-eyed-Susan August – September Broadcast

Clasping coneflower August – September Broadcast

Plains coreopsis August – September Broadcast

Partridge pea March – April Drill

Bur marigold August - September* Broadcast

Lyre-leaf sage August – September Broadcast

Swamp rose-mallow April – May Broadcast

Cardinal flower August – September Broadcast**

Purple coneflower August – September Broadcast

Meadow beauty August - September* Broadcast**

* Will not germinate until the following spring.

** Small seed size makes direct sowing difficult.

Smaller increase fields have also been established using greenhouse-grown transplants. Seed is

sown in the greenhouse in the summer or late winter depending on whether the field will be

planted in the fall or spring. Seedlings are grown in plastic bedding plant containers and planted

in the field using a mechanical vegetable transplanter or occasionally by hand using a dibble bar.

Field preparation methods are basically the same as for seed establishment, with the exception of

cultipacking.

These wildflower species are well adapted to local soil conditions and therefore require fairly low

amounts of fertility for optimum seed production. Fertilizer is normally applied in the spring.

Rates used are 224 kg ha-1 13-13-13 on normal soils or 112 kg ammonium nitrate on moist soils.

Clasping coneflower requires slightly higher N rates for proper growth and is fertilized at a rate of

168 to 224 kg ha-1 ammonium nitrate. Soil tests are taken periodically and the fields are limed if

the soil pH falls into the low range.

Mowing is the primary weed control method used at the PMC. Appropriately timed mowing

(Table 4) can control the growth of undesirable vegetation and improve growth of wildflower

species, but will not maintain the fields in a weed-free state. Several species flower late in the

year and must not be mowed during critical growth stages in the summer, which allows many

weed species to grow unfettered. This reality has required an adjustment of expectations on the

part of PMC staff and others regarding attainable field appearance.

Although many commercial producers use cultivation to control weeds in wildflower fields, past

experience at the PMC has shown poor results from this practice. Many of the plants died or

showed signs of severe stress following cultivation. It appeared that the main causes of this were

soil deposition on or around the root crown and root disturbance. Silt loam soils at the PMC have

a tendency to form clods, which can then be deposited in the plant row by the cultivator. Species

such as black-eyed Susan and purple coneflower are highly susceptible to crown rot following
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

145

such deposition, although several other species can also be affected. Most of these species

grow naturally in waste sites that are not subject to soil disturbance; therefore, the plants are not

adapted to root disturbance such as occurs during cultivation. Partridge pea is an invader

species on disturbed sites (Grelen and Hughes 1984), which explains why it can be drilled and

cultivated early in the growing season before the plant canopy gets too dense.

Table 4. Recommended mowing schedules for wildflower species.

Species Mowing Schedule

Black-eyed Susan

Plains coreopsis

Clasping coneflower

Early April (if needed), mid-July, early September, after

frost

Lyre-leaf sage Late May and every 6 weeks until frost

Partridge pea

Bur marigold

Late May, after frost

Meadow beauty

Purple coneflower

Cardinal flower

April, early to mid-October, after frost

Swamp rose-mallow February to March

Herbicides may also be used to control weeds; however, few herbicides are labeled specifically

for wildflower production. Wildflower seed is not considered to be a food crop and use of most

herbicides would not present an undue risk to humans or the environment; therefore, additional

herbicides have been used on species where plant tolerance has been proven. Glyphosate was

mentioned previously for use in field establishment. It is regularly applied to clasping coneflower

and plains coreopsis fields after harvest to control weeds before germination occurs in the fall.

Both of these are annual species that die back after harvest. The fields are then disked and

cultipacked similar to newly established ones. This herbicide is also sometimes used to renovate

black-eyed Susan fields that have become weedy; however, it will kill perenniating plants and the

field must then be treated as a newly established one. It can also be used on swamp rosemallow in the early spring before shoot emergence. Sethoxydim (Poast Plus) has been used

on all species at a rate of 0.28 kg ai ha-1 for postemergence control of grasses. Imazameth

(Plateau) is a new herbicide developed for pre and postemergence weed control in native

grasses and wildflowers. It is labeled for use on black-eyed Susan, plains coreopsis, purple

coneflower, and partridge pea. It has been used at the PMC preemergence on fields of clasping

coneflower and plains coreopsis and postemergence on black-eyed Susan and partridge pea

(with some burning) at a rate of 0.105 kg ai ha-1. Plot tests showed excellent weed control and no

damage on black-eyed Susan when applied post-emergence at a slightly higher rate of 0.14 kg ai

ha-1. Legumes such as partridge pea are sensitive to rates of imazameth above 0.07 kg ai ha-1

and to applications at very young growth stages. DCPA (Dacthal) can be safely used

preemergence on most of these species; however, its wettable powder formulation and limited

spectrum of weed control make it less desirable for regular use. Short residual preemergence

herbicides often provide less than desired weed control for many of these species because they

normally germinate in the fall, whereas the majority of problem weeds germinate in the spring or

summer. DCPA (8.96 kg ai ha-1) has been used at the PMC mainly for weed control on fields that

were mechanically transplanted in the spring. Dicamba (Banvel) or 2,4-D can be used postharvest on clasping coneflower and plains coreopsis fields, in addition to glyphosate, to control

problem broadleaf weeds. Recommended rates are 0.56 to 1.12 kg ai ha-1 (dicamba) and 0.71 to

0.95 kg acid equivalent (ae) ha-1 (2,4-D). Metolachlor (Dual) is used for preemergence weed

control on partridge pea at a rate of 2.24 kg ai ha-1. Tolerance testing at the PMC demonstrated

that several of the other wildflower species are sensitive to this herbicide. Another formulation

(Pennant) has been recommended for plains coreopsis (Skroch et al. 1982); however, little

tolerance to Dual was demonstrated in PMC tolerance testing. Another herbicide used on

partridge pea is bentazon (Basagran), largely for postemergence control of yellow nutsedge
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

146

[Cyperus esculentus L.], at a rate of 1.12 kg ai ha-1. Plot tests at the PMC have shown that blackeyed Susan and clasping coneflower may be somewhat tolerant to this herbicide.

All species are indeterminate in their flowering and seed ripening habits and seed of some

species is prone to shattering; therefore, harvest must be timed correctly to obtain the highest

possible yields. Approximate harvest dates are listed in Table 5; however, they can vary by

several weeks from one year to another. Most production fields are harvested using a standard

commercial combine; however, some small production fields may be harvested by hand. Practice

was required to learn how to successfully combine this seed. The air speed must be severely

reduced to prevent seed from blowing out the back of the combine. In the past, this necessitated

the placement of a piece of cardboard over the air intake; however, purchase of a new combine

with a slow speed fan kit simplified this operation. Experience has also determined the

appropriate concave settings to adequately thresh the seed of each species. Species such as

plains coreopsis still have a great deal of green plant matter when harvested, which can wrap

around and potentially stall the combine header. The new combine has a reversible header that

makes this problem somewhat easier to manage. Augers for commercial combines are designed

for moving larger-sized seed of typical agronomic crops. Much of this smaller wildflower seed

tends to pack together in the grain hopper, which makes it difficult to remove using the auger.

There is no adequate technique that can be used to overcome this problem. Hand-harvested

seed is fed though portable threshers to release the seed and then treated in a similar manner as

combined seed. After harvesting, seed is spread on the floor of a ventilated building and allowed

to dry before cleaning. Fans are used to provide air movement and the seed is turned as needed

to prevent heating. Seed is cleaned with an air-screen cleaner. Experience has also determined

the correct screen combinations and cleaner settings for each species. Usually several stages of

cleaning are required, each using different screens or settings, to adequately clean this seed.

The limited weed control options discussed previously generally result in seed of a large number

of plant species being present in the combined seed as well as much inert matter. It is not

possible to remove all of these contaminants with available cleaner screens. Also, small seed

size severely limits the amount of air separation that can be used. Differences in size, shape, or

other characteristics make seed of some species easier to clean more completely than others.

Once seed has been cleaned it is bagged and stored in a cooler maintained at approximately

13°C and 45% relative humidity, until requested by conservation districts.

Table 5. Approximate harvest dates for wildflower species.

Species Harvest Date

Black-eyed Susan Mid-July

Clasping coneflower Late June to early July

Plains coreopsis Mid- to late July

Partridge pea Early October

Bur marigold Late October to early November

Lyre-leaf sage Early to mid-May

Swamp rose-mallow Mid-September

Cardinal flower Early October

Purple coneflower Early to mid-September

Meadow beauty Late September to early October

Conclusions

Production of native wildflower seed is an activity that allows the PMC to make use of

acknowledged seed production experience to benefit conservation districts and ultimately

individuals within the state of Mississippi. The PMC currently plans to develop a publication on

harvesting and seed cleaning techniques for these and other conservation plants in order to

encourage others to begin production of these species.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

147

References

Grelen, H. E. and R. H. Hughes. 1984. Common herbaceous plants of southern forest range.

USDA Forest Service, Southern Forest Experiment Station Research Paper SO-210, New

Orleans, LA. 147 p.

Skroch, W. A., J. C. Neal, J. F. Derr, and A. Senesac. 1992. Weed control suggestions for

Christmas trees, woody ornamentals, and flowers. Publication Number AG-427. North Carolina

Cooperative Extension Service, North Carolina State University, Raleigh, NC. 100 p.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

148

Treatments to Overcome Dormancy of Eastern Gamagrass Seed

Janet M. Grabowski and Joel L. Douglas1

Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a warm season perennial grass, native to

the eastern and central portions of the United States and the West Indies (Hitchcock 1951). It

has been recognized as a highly palatable forage species (Polk and Adcock 1964; Rechenthin

1951); however, its utilization in forage systems has largely been hampered by seed production

and establishment problems (Ahring and Frank 1968; Anderson 1990).

The seed unit of eastern gamagrass consists of a caryopsis surrounded by a hard, indurate,

cupulate fruit case (Anderson 1985). Many years ago, researchers such as Crocker (1916)

recognized that hard seed or fruit coats could prevent germination by restricting the absorption of

water or oxygen, or by physically restricting growth of the embryo. Seed coverings of many

species will also contain chemical inhibitors that prevent germination from occurring (Hartmann

and Kester 1975). Anderson (1985) found that germination inhibitors were not present in the fruit

coverings of eastern gamagrass and that these coverings did not restrict germination by

preventing the passage of respired carbon dioxide out of the fruit. Since the coverings do not act

as a barrier to movement of carbon dioxide, they likely would not impose any restrictions on the

absorption of oxygen. Removal of the cupule promoted germination (Anderson 1990) but,

unfortunately, there is no effective way for seed producers to accomplish this for larger seed lots

without causing a significant amount of damage to the seed. Anderson (1985) suggested that the

cupule mainly affected germination by imposing limits on the environmental conditions under

which germination could occur. The restrictive effect of the cupule can be overcome by a period

of cold, moist stratification (Ahring and Frank 1968; Anderson 1985). Anderson (1990) found that

there were genetic differences between populations that affected their response to stratification.

Ahring and Frank (1968) tested various stratification intervals ranging from one to nine weeks and

obtained best germination for the two seed lots tested with 6 weeks of stratification at 5 to 10°C.

This stratification requirement presents several agronomic problems for potential growers. First

of all, the seed producer must be capable of providing the stratification treatment. Current

recommendations are to hydrate the seed by soaking overnight in a 0.5 percent solution of

Thiram 42S fungicide to control seed pathogens, and stratifying for 6 to 12 weeks at 1 to 4°C

(Row 1998). If stratified seed is subsequently exposed to environmental conditions that are not

conducive to germination, then the seed may enter secondary dormancy (Hartmann and Kester

1975; Simpson 1990) and will not germinate until the following year. This problem is most severe

when adequate soil moisture is not available after planting, and in many cases, would require

irrigation to ensure establishment (Row 1998). Also, many growers are not accustomed to

handling and planting stratified seed. It should be refrigerated before planting and protected from

high temperatures during the planting operation. For these reasons, an alternative seed

treatment that could simplify the production and planting operation would be desirable.

Hot water treatments have been used to modify hard seed coats and promote germination

(Hartmann and Kester 1975). Keith (1981) successfully treated a hard-seeded cotton

[Gossypium hirsutum L.] breeding line by soaking the seed in a hot water bath for 60 seconds at

85°C. Seed is usually planted immediately following hot water treatment, but certain types of

seed have been allowed to dry and were then stored without greatly affecting germination

percentages (Hartmann and Kester 1975). If eastern gamagrass seed responded to hot water

treatment, it might be less likely to encounter the potential secondary dormancy problems

associated with stratification and would therefore become more attractive to potential growers.

 

1

 United States Department of Agriculture, Natural Resources Conservation Service, Jamie L.

Whitten Plant Materials Center, Coffeeville, MS 38922-2652.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

149

Various types of chemical stimulants have been shown to promote germination (Hartmann and

Kester 1975). If an appropriate stimulant or combination of stimulants could be found for use on

eastern gamagrass seed, planting operations could be simplified and establishment rates

improved. Soaking seed in a potassium nitrate (KNO3) solution is one method commonly used to

improve germination of freshly harvested seed (Hartmann and Kester 1975). Ahring and Frank

(1968) found that soaking eastern gamagrass seed in sodium hypochlorite or KNO3 solutions had

no effect on germination. Soaking in a solution of ethylene chlorohydrin slightly increased

germination, but the effect was not significant and germination percentages were much lower

than stratified seed. Row (1998) found that soaking in KNO3 or Thiram did not improve

germination over soaking seed in water alone. Exogenous applications of gibberellins and

cytokinins have also been shown to stimulate germination of various types of seed (Hartmann

and Kester 1975). It has been reported that eastern gamagrass seed is deficient in gibberellins

and cytokinins. Treating seed with gibberellic acid (GA) improved early, but not total germination

of eastern gamagrass seed (Anderson,1985).

Methods

The efficacy of hot water soaking was tested on seed from two accessions of eastern gamagrass,

9058543, which was originally collected in Pushmataha County, Oklahoma, and 9062708, from

Williamsburg County, South Carolina. Seed were hand collected from plants growing at the

Jamie L. Whitten Plant Materials Center (PMC) in Coffeeville, Mississippi during the months of

July and August 1997. Seed harvested from eastern gamagrass often contains a fairly high and

often variable percentage of unfilled seed, either without a caryopsis or with a shriveled, nonviable caryopsis (Ahring and Frank 1968; Douglas et al. 1997). To determine seed fill, 30 seed of

each lot were opened and examined for the presence of a healthy caryopsis. It was found that

9058543 contained an average of 87 percent filled seed and 9062708 averaged 80 percent filled

seed. Seed fill was fairly high because the seed was collected by hand, not combine harvested.

To determine appropriate hot water temperatures for testing, a non-replicated preliminary study

was conducted using a seed lot from a previous experiment that contained a mixture of

accessions cleaned to 90 percent fill. Temperatures used were 70, 80, 90, and 100°C and

soaking duration ranged from 60 to 240 seconds in increments of 30 seconds using the methods

outlined below. Seed from both the 90 and 100°C treatments exhibited zero percent germination.

Because of this result, the 100°C temperature was dropped from further testing and 90°C was

retained as the upper testing limit. Treatment intervals for final testing were not altered from

those used in the preliminary test.

Seed treatments used in this study were the hot water treatments outlined above, plus

stratification, and an untreated control. Twenty-five seed were used for each treatment. Samples

were hot water treated by placing the seed in a basket constructed of hardware cloth (6 mm

square openings) lined with aluminum window screen; an attached wire handle facilitated

placement in and removal from the water bath. A cover was made from similar window screen to

prevent seed from floating out of the basket during treatment. The basket containing the seed

was submerged in a one liter beaker containing distilled water placed on a multiple setting hot

plate previously calibrated to provide the appropriate temperatures. Care was taken to ensure

that temperatures did not vary by more than 2°C from the target temperature during the treatment

period. After hot water treatment, seed samples were placed in a greenhouse and allowed to dry

before planting. A quantity of seed was prepared for stratification by soaking overnight in tap

water. It was then enclosed in a self-closing plastic bag with a minimal amount of free water, and

put in a cooler maintained at 42°F with no humidity control.

The experiment was conducted twice. For the first treatment run, seed of both accessions were

stratified on 24 February 1998. Seed of 9058543 was hot water treated on 25 March 1998 and all

seed treatments for that accession were planted the following day. Accession 9062708 was hot

water treated on 26 March 1998 and all treatments were also planted the following day. For the

second run, seed was stratified on 24 April 1998; 9062708 was hot water treated on 26 May
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

150

1998, and 9058543 was hot water treated on 27 May 1998 with all treatments planted the day

after hot water treatment as before. Germination containers used were 17.8 cm x 13.3 cm x 5.9

cm plastic bedding plant liners and seeds were planted 0.6 to 1.3 cm deep in a commercial

potting medium. The test was arranged as a randomized complete block with three replications

in a split plot design with accessions as the main plot and seed treatments as the split plot.

Germination containers were placed in a germinator maintained at 20/30°C night/day regime, with

an eight-hour day period when the internal lights were on. There are no Association of Official

Seed Analysts recommendations for eastern gamagrass germination testing; however, this

temperature regime was recommended by seed laboratory personnel experienced in testing this

species (J. Franklin, personal communication). All containers were irrigated thoroughly following

planting and watered throughout the testing period as necessary. Germination counts were made

every seven days over a five week period and a total germination percentage was determined for

each treatment. This data was subjected to an analysis of variance (ANOVA) using MSTAT-C

(Michigan State Univ. 1988) and appropriate mean separations were performed at the five

percent level of probability (P<0.05) using a least significant difference test.

A non-replicated field trial using seed of both accessions was planted on 28 May 1998 at the

PMC on an Oaklimiter silt loam soil. Seed treatments used were stratification (seed placed in

stratification on 24 April 1998), untreated seed, and the highest ranking of the hot water

treatments from the first run of the germinator experiment. Hot water treatments used were 70°C

for 60, 90, 120, 150,180, 210, 240 sec, and 80°C for 60 sec. Seed sample size was 25 seed as

in the germinator test. Hot water treated seed was dried in the greenhouse for one to two days

before planting. Seed samples were planted by forming a shallow row with a hoe, hand sowing

the seed, and covering to a depth of about 2.5 cm. Germination counts were made every three or

four days until 9 July 1998.

Accession 9062680 (collected in Montgomery County, Tennessee) has been selected by PMC

personnel as a superior accession. Seed of this accession was not available in early 1998 when

the original testing was performed, so it could not be included in those trials. Seed was collected

in July and August of 1998 and was subsequently tested in the germinator to determine its

response to hot water treatment. For this study, seed quality was improved by separating out the

heavier seed using a South Dakota Seed Blower (Seedburo Equipment Co., Chicago, Ill.); fill was

determined to be 87 percent using similar methods to those of the previous test. Limited seed

quantities were available which restricted the number of seed treatments that could be tested.

Treatments used were stratification, control, and hot water soaking at 70°C for 240 sec, which

ranked as the top hot water treatment for both accessions tested previously. This study was

arranged as a randomized complete block with three replications. The seed was stratified on 8

August 1998, and was hot water treated in the morning of 10 November 1998 and all treatments

were planted later that day. Methods used were the same as those for the previous germinator

trials, except that germination counts were made for six weeks rather than five, because

germination rates were slightly slower in this test. Data was subjected to ANOVA using MSTATC (Michigan State Univ. 1988) and mean separation was performed using Tukey’s honestly

significant difference test (HSD) at P<0.05.

All three accessions were tested for the effect of soaking in KNO3 or GA solutions on germination

rate and percentage of hot water treated and stratified seed. Stratification treatments consisted

of soaking seed in a 0.2% KNO3 solution, 1000 mg L-1 GA solution, or distilled water for 24 hours

before commencement of the cold period. ProGibb, a commercial formulation of gibberellic acid

was used as the GA source. After soaking, seeds were rinsed with distilled water before being

placed in the cooler on 9 March 1999. Seed samples were hot water treated at 70°C for 240 sec

and then soaked in the same treatments as used for stratification. Seeds were then rinsed with

distilled water and kept moist until planting in the field or germinator. An untreated control was

also included. Seed samples for the field test were hot water treated on 3 May 1999 and all

treatments planted the following day. Stratified seed was placed in an insulated container to limit

heat exposure while being transported to and before planting in the field. Seed for the germinator

test were hot water treated on 5 May 1999 and planted 6 May 1999. Sample sizes used were 25
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

151

seed for the field test and ten seed for the germinator test. The tests were arranged as a two

factor randomized complete block with six replications for the field test and four for the germinator

test. The field test was planted at the PMC on an Oaklimiter silt loam soil using similar methods

to those for the preliminary field test above. After planting, the study area was treated with 1.68

kg ha-1 of atrazine for weed control. Seed samples for the germinator test were planted using the

methods outlined for the initial hot water tests. Germination counts were made weekly for 42

days, when the germinator study was terminated; counting seedlings in the field test became

difficult after this time period due to weed growth, but the study was left in place in order to do a

final survival count in the fall. Data from these tests were subjected to an analysis of variance

(ANOVA) using MSTAT-C (Michigan State Univ. 1988) and appropriate mean separations were

performed at the five percent level of probability (P<0.05) using a least significant difference test.

Results

Hot Water Treatment: The germination percentages for each accession and each trial run were

first analyzed separately to determine trends in responses to the treatments. The accessions

responded in a similar manner to the seed treatments in each run of the experiment, so the data

for each accession was averaged across the two runs. This data is presented in Tables 1 and 2.

Germination rates were fairly low as is typical of eastern gamagrass. It appears that all 90°C

treatments and the 80°C treatments soaked for 150 sec or longer may have been lethal or

otherwise prevented from germinating. The true cause for this lack of germination was not

determined, because it was apparent that such treatments would be unacceptable which made

further examination irrelevant.

Table 1. Total germination percentages of eastern gamagrass accession 9058543 exposed to

various seed treatments averaged over two trial runs.

Seed Treatment Soaking Time Water Temperature (°C)

(Sec) 70 80 90

----------------------%----------------------

Hot Water Soak 60 11 19 0

90 7 6 0

120 13 1 0

150 9 0 0

180 12 0 0

210 17 0 0

240 22 0 0

Untreated 11

Stratified 57

Table 2. Total germination percentages of eastern gamagrass accession 9062708 exposed to

various seed treatments averaged over two trial runs.

Seed Treatment Soaking Time Water Temperature (°C)

(Sec) 70 80 90

----------------------%----------------------

Hot Water Soak 60 27 21 0

90 29 5 0

120 28 1 0

150 25 0 0

180 28 0 0

210 30 0 0

240 30 0 0

Untreated 24

Stratified 42
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

152

Those treatments that yielded zero germination were dropped from the final ANOVA. The

resulting data analysis showed that there was a significant interaction effect between accession

and seed treatment (Figure 1). There are several factors that could have contributed to this

interaction. First, germination percentages for all seed treatments, except the stratification

treatment and the 80°C treatments, were much higher for 9062708. Secondly, germination of

stratified 9058543 was much greater than that of any of the other treatments for this accession,

but for 9062708, several of the hot water treatments had germination percentages similar in

magnitude to those of the stratification treatment. In fact, the germination percentage of 9058543

stratified seed was significantly higher than that of same treatment for the other accession.

Anderson (1990) noted variability in stratification response between genotypes of eastern

gamagrass from different locations. From these results, it seems likely that of the two

accessions, 9062708 is not as dependent on stratification for optimum germination. Also, the two

accessions did not respond in a similar manner to the hot water treatments. When each

accession is looked at separately, the 70°C 240 sec treatment provided the best germination of

any of the hot water treatments. However, the 80°C 60 sec treatment would be ranked as the

second best hot water treatment for 9058543, whereas this treatment would have ranked as the

eighth best hot water treatment for 9062708, below even the control treatment. Germination

percentages of the 80°C 90 and 120 sec treatments were very low, which indicates that there

may have been damage to the seed.

0

10

20

30

40

50

60

Control

Strat.

70C 60s

70C 90s

70C 120s70C 150s

70C 180s

70C 210s70C 240s

80C 60s

80C 90s

80C 120s

Seed Treatment

% Germination

9058543

9062708

LSD (0.05)

9.7

Figure 1. Interaction effect of selected seed treatments on total germination percentages of

eastern gamagrass seed

Figure 2 illustrates differences in germination rate for selected treatments by graphing the

germination percentage mean over both accessions at each evaluation interval. Stratified seed

germinated much more quickly than the other treatments. Anderson (1985) found that stratified

seed exposed to appropriate temperatures germinated very rapidly, with several treatments

showing relatively high germination percentages within five days. In this experiment, none of the

treatments germinated by the first count at seven days. Anderson used filter paper as the
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

153

germination medium and could have detected germination much more quickly than in this study

where seed were planted in a potting medium. Also, Anderson was working with populations of

eastern gamagrass that originated from southern Illinois, which is father north than the collection

site of the accessions used in this test. He notes that eastern gamagrass has naturally occurring

races with various ploidy levels. Although Anderson did not specify the ploidy level of the seed

used, most northerly accessions tend to be diploid whereas the southern accessions used in this

study were tetraploid (C. Dewald, personal communication). Tetraploid seed has been shown to

have a larger, heavier fruit case than diploid seed (Douglas 1999) and this larger fruit case

probably imposes more restrictions on the embryo, which may have slowed the germination rate

for these accessions. The germination rate of the hot water treated seed was somewhat similar

to that of the control, although final germination percentages were higher than those of the

control. This response has profound agronomic implications. Even if final germination

percentage of the hot water treated seed were equal to that of stratified seed, the fact that it

germinates more slowly subjects the seedling to increased competition from other plant species,

which could prevent establishment.

Germination Rate

0

10

20

30

40

50

60

7 14 21 28 35

Evaluation Period (days)

% Germination

Strat.

70C 210s

70C 240s

Control

Figure 2. Mean germination percentages of stratified (Strat.), two selected hot water treatments,

and untreated seed (Control).

Data for the preliminary field planting is presented in Table 3. No herbicides were used, so

locating the seedlings for germination counts was somewhat difficult and this probably affected

the counts made on several evaluation dates. The data presented is the maximum count

recorded for each treatment, and may not be the true total germination percentage. Field

response of the hot water treated seed was disappointing; however, weather conditions during

the treatment period were unusually hot and dry. There was almost no germination recorded for

any of the hot water treated seed of accession 9062708, the same accession that showed a more

favorable response in the germinator. Those hot water treatments with the highest germination

percentages for 9058543 in the field were not those that performed best for this accession in the

germinator. Keith (1981) found a similar disparity in the hard-seeded cotton line between those

hot water treatments with the best germination percentages in the laboratory as opposed to those

that germinated best in the field. Final recommendations for treating this cotton seed line were

based on those treatments that performed best in the field. Due to the unusual environmental

conditions experienced during this study, such conclusions would not be appropriate in this case.

It is interesting to note the high germination percentages recorded for stratified seed. Several

researchers have documented that secondary dormancy can be induced in stratified eastern
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

154

gamagrass seed by drought (Row 1998); however, germination percentages for these accessions

were higher in the hot dry conditions in the field than they were for the more ideal conditions in

the germinator. This could possibly be an instance of the seed responding favorably to high

temperatures. Anderson (1985) noted that stratified seed germinated much better at a higher

temperature (32°C) than at a lower temperature (25°C). Possibly 20°C/30°C is not the

appropriate temperature regime to produce optimum germination percentages of eastern

gamagrass seed and seed testing methods should be altered.

Table 3. Total germination percentages for a preliminary field test of two eastern gamagrass

accessions exposed to various seed treatment regimes.

Seed Treatment Germination

9058543 9062708

---------------------------%---------------------------

Untreated 0 0

Stratified 68 84

70°C 60 sec 0 0

70°C 90 sec 4 0

70°C 120 sec 16 0

70°C 150 sec 0 0

70°C 180 sec 24 4

70°C 210 sec 0 0

70°C 240 sec 0 0

80°C 60 sec 0 0

Table 4 shows the response of accession 9062680 to the three seed treatments used. This

accession showed a somewhat favorable response to the 70°C 240 sec hot water treatment, but

seed germination for this treatment was still significantly lower than that of the stratified seed.

From this data, it appears that the response of this accession to the hot water treatment is

probably similar to that shown for 9058543.

Table 4. Germination of eastern gamagrass accession 9062680 exposed to three seed

treatment regimes.

Seed Treatment Germination

----------%----------

Untreated 4b*

Stratified 23a

70°C 240 sec 15ab

Treatment means followed by different letters are significantly different by Tukey’s HSD at

P<0.05.

Chemical Seed Stimulants: Germination percentages for both locations of testing are presented

in Table 5. There was an interaction effect between accession and seed treatment in both tests,

because accessions responded differently to the various seed treatments. Germination of hot

water treated seed was much higher in the germinator than in the field, which concurs with results

from preliminary field testing (Table 3). Non-conducive environmental conditions were cited as a

possible cause for the lack of germination in the preliminary test, but conditions were highly

favorable during the germination period in this study (data not presented). It appears that hot

water soaking does not provide sufficient seed coat modification to permit field establishment of

eastern gamagrass seed. Germination of stratified 9062680 seed was lower than the other two

accessions and the difference was significant for both accessions in the field test and one

accession in the germinator test. Soaking in KNO3 or GA slightly improved germination of hot
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

155

water treated seed in the germinator; however, neither of these chemicals consistently improved

germination of stratified seed. Row (1998) reported that a 24-hour exposure to KNO3 reduced

germination of some seed lots, but no such reduction was noted in this study. Response to KNO3

appeared to be greater in the field than in the germinator test.

Table 5. The effect of chemical stimulants on germination of stratified and hot

water treated seed of three eastern gamagrass accessions.

Accession Seed Treatment Germination

Germinator Field

----------------------%----------------------

9058543 Stratified 63 49

GA + Stratified 60 57

KNO3 + Stratified 58 62

Hot Water 8 2

Hot Water + GA 23 3

Hot Water + KNO3 13 4

Untreated 3 1

9062708 Stratified 70 49

GA + Stratified 58 45

KNO3 + Stratified 43 49

Hot Water 20 2

Hot Water + GA 23 0

Hot Water + KNO3 13 1

Untreated 5 2

9062680 Stratified 51 38

GA + Stratified 27 47

KNO3 + Stratified 21 36

Hot Water 8 3

Hot Water + GA 21 5

Hot Water + KNO3 21 1

Untreated 8 1

LSD (0.05) 19 10

Figure 3 illustrates germination rates for the three stratification treatments and the control in the

germinator test. Germination rate data from the field test is not presented because interference

from weeds prevented accurate counts during later evaluation dates. Early germination was

improved by GA exposure; however, the difference was not significant in the germinator. In the

field, early germination was significantly greater for two of the three accessions. This finding is in

agreement with Anderson (1985), who reported that GA increased early but not total germination

percentages of seed with intact fruit cases. The GA treatment caused abnormal elongation and

chlorosis of the seedlings, which made the shoots highly susceptible to being broken by wind or

physical contact. Although Anderson (1985) also used a 1000 mg L-1 concentration of GA,

abnormal growth was not reported in that study. Anderson (1985) did not specify the length of

the GA treatment period or what formulation of GA was used. In this study, GA was added to the

pre-stratification soak, which would appear to be a commercially acceptable treatment method.

Reduced concentrations may be required to effectively treat seed with the GA formulation and

treatment duration used in this study. KNO3 had no effect on germination rate.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

156

Germination Rate

0

10

20

30

40

50

60

70

7 14 21 28 35 42

Evaluation Period (days)

% Germination

St.

GA + St.

KNO3 + St.

Control

Figure 3. Mean germination percentages of stratified (St.) seed with or without pretreatment with

chemical stimulants (GA or KNO3) and untreated seed (Control) in the germinator.

Conclusions

Although eastern gamagrass seed responded to hot water soaking in the germinator, the effect

on field-sown seed was minimal. Hot water treatments were not able to overcome the fruit coat

imposed dormancy as effectively as cold stratification. Germination rate of hot water treated seed

was much slower than that of stratified seed, which could affect its establishment potential.

Treating seed with GA increased early emergence of stratified seed; however, appropriate rates

and treatment methods need to be determined before commercial use could be recommended.

Treatment with KNO3 did not appear to adversely affect germination. Various combinations of

these two chemicals will be tested in the future, along with other stimulants such as cytokinins.

Seed of different eastern gamagrass genotypes appeared to respond differently to all seed

treatments tested.

References

Ahring, R. M., and H. Frank. 1968. Establishment of eastern gamagrass from seed and

vegetative propagation. Journal of Range Management. 21: 27-30.

Anderson, R. C. 1985. Aspects of the germination ecology and biomass production of eastern

gamagrass (Tripsacum dactyloides L.). Botanical Gazette. 146: 353-364.

Anderson, R. C. 1990. Aspects of the seed biology of eastern gamagrass. In Eastern

Gamagrass Conference Proceedings: 1989 January 23-25: The Kerr Center for Sustainable

Agriculture, Poteau, OK. 4 p.

Crocker, W. 1916. Mechanics of dormancy in seeds. American Journal of Botany. 3(3): 99-120.

Douglas, J. 1999. Eastern gamagrass establishment: I. Greenhouse planting depth. Technote

14(3), Jamie L. Whitten Plant Materials Center, Coffeeville, MS. 5 p.

Douglas, J., J. Grabowski, and B. Keith. A comparison of seed cleaning techniques for improving

quality of eastern gamagrass seed. Journal of Seed Science Technology (in Press)
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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Hartmann, H. T., and D. E. Kester. 1975. Plant propagation principles and practices. 3rd edition,

Prentice-Hall, Englewood Cliffs, NJ. 662 p.

Hitchcock, A. S. 1951. Manual of the grasses of the United States. USDA, Miscellaneous

Publication 200, 2nd edition, US Gov. Printing Office, Washington, DC. 1051 p.

Keith, B. C. 1981. Comparison of some characteristics in a hardseeded cotton breeding line

(16B-7-2) with Stoneville 213. MS Thesis, Mississippi State University, Mississippi State, MS. 37

p.

Michigan State University. 1988. MSTAT-C Microcomputer Statistical Program.

Polk, D. G., and W. L. Adcock. 1964. Eastern gamagrass. The Cattleman. 50: 82-84.

Rechenthin, C. A. 1951. Range grasses in the Southwest: eastern gamagrass, Texas cupgrass,

Pan American balsamscale, smooth cordgrass. The Cattleman. 38: 110-112.

Row, J. M. 1998. Establishment of eastern gamagrass with pre-germination seed treatments.

MS Thesis, Kansas State University, Manhattan, KS. 47 p.

Simpson, G. M. 1990. Seed dormancy in grasses. Cambridge University Press, Cambridge,

UK. 297 p.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

158

Selecting Native Plants Using VegSpec: A Web-based System

James F. Henson, David Pyke, Robert E. Riggins,

Keith Ticknor, John R. Patterson, and Phil H. Smith1

Abstract

VegSpec is a decision support system designed to assist in the selection of appropriate plant

species for site-specific conservation problems. VegSpec contains a library of approximately

2500 species and cultivars. Each species and cultivar is characterized by 92 attributes. Users

characterize a site by selecting a soil map unit and the nearest climate station from choice lists,

which cover the entire United States. Users also characterize the site’s current conditions and

the objectives of the planting. VegSpec uses these specifications as filters to select appropriate

plants from the plant library. The filters are encoded as a series of expert rules. These rules

select species and cultivars based on the 92 attributes. A planting design module provides

information about propagule types, optimum-planting dates, species compatibility in mixed

plantings, and establishment methods. The planting design module also provides spreadsheets,

which users can use to calculate the required seed and vegetative propagule amounts for both

single and multiple species plantings.

Vegspec Demonstration

We present an example of VegSpec use. The site is in Montgomery County, Maryland on a

Hyattstown soil with a steep, severely eroding, and east-facing slope. The landowner wants to

control water erosion on this land and prefers to use native herbaceous plants.

From Netscape 4.06/Internet Explorer 4.0 or higher version, enter the PLANTS Project homepage

address http://plants.usda.gov followed by a carriage return on the web address line.

In the box entitled Plant tools click on VegSpec.

On the thin green bar in the upper half of the screen, click on Start VegSpec.

Please read the disclaimer page. The VegSpec running mode will be selected as Site Specific

as the default. Do not change this. Once you have finished reading the disclaimer, click OK.

This is the beginning of the program. You are on the Site Description section. The Site

Description icon on the top of the page will bring you back to this page from other locations in

the program. You will begin to fill out all sections on this page.

1) Under State select Maryland. That is all that is required here. The others (Site, User

and Project Names) are optional and will show on the report.

2) Soils

3) The soil surveys for Maryland are already selected, so on the 2nd line Soil Survey

Area ID click on the arrow to pull down the menu. Highlight and click on the

Montgomery County, Maryland:31. Wait for the screen to refresh.

4) For the Soil Map Unit, click on the arrow, highlight and click on the Hyattstown

 

1 James F. Henson, USDA, NRCS, NPDC, P.O. Box 74490, Baton Rouge, LA 70874-4490; David

Pyke, USGS, FRESC, 3200 SW Jefferson Way, Corvallis, OR 97331; Robert E. Riggins, CECERCN-C, P.O. Box 9005, Champaign, IL 61820-9005; Keith Ticknor, USDA, NRCS, ECS, P.O. Box

2890, Washington DC 20013-2890; John R. Patterson, USDA, NRCS, NSSC, 100 Centennial

Mall North, Lincoln, NE 68508-3866; Phil H. Smith, USDA, NRCS, ITC, 2625 Redwing Road,

Suite 110, Fort Collins, CO 80526-2878. *Corresponding author (jhenson@npdc.usda.gov).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

159

channery silt loam, 25 to 45 percent slope, very ...: 109E. Wait for the screen to

refresh.

5) For the Soil Component, Hyattstown 90% is the default because it is the greatest

component in this map unit. If you select another component, then wait for the

screen to refresh after you select it before you continue.

6) You may view Soil Attributes and the MLRA for the site by selecting the blue

hypertext soil attributes suboption. For this demo, we will not change any features.

If you have gone here, then select Cancel to return. If you made changes, click on

the Site Description icon.

7) Climate

8) For the Climate Station, click on the arrow, highlight and click on

MD7705:ROCKVILLE 1 NE. Wait for the screen to refresh.

9) You may look at the hypertext climate attribute suboption if you wanted to change

any values. For this demo, don’t change anything. If you entered this section, then

select Cancel. If you changed values and want to save them, then click on Site

Description icon to return to the Site Description page.

10) Landscape

11) Under Generally, what aspect does the site face? Click the radio button to the

left of East.

12) For this demo, we will leave the remaining three selections in the default state.

This completes the Site Description section.

At the top of the page, click on the Objectives icon.

13) To choose a Practice, click the radical button to the left of Critical Area Planting.

Wait for the screen to refresh.

14) Under Purpose, you will select 1 purpose. Click the box for Water Erosion Control,

Then click on Accept Purpose(s). Wait for the screen to refresh.

15) Under Sub-Purpose, do not select a Sub-Purpose.

16) Optional Plant Characteristics

17) Under Plant Type click the box to the left of Grass.

18) For this demo, leave Commercial Availability in the default mode.

19) Under Plant Origin click the box to the left of Native to U.S.

This completes the Objectives section.

At the top of the page, click on the Select Plants icon. It may take up to a minute to provide the

new screen. The program is processing and selecting potential plants for the site.

20) There should be a number below the column labeled Potential Plants. It should come

up with 39 plants. These are the native grasses that are suitable for water erosion

control on Hayttstown soil in Montgomery County, Maryland.

21) Now you will highlight the species on the Potential Plants column that you and the

landowner choose for this site. To highlight them, hold down the ctrl-key and click on

the selected plants. For this example, highlight: (1) field paspalum:n.a.:PALA10; (2)

purple lovegrass:n.a.:ERSP; and (3) purpletop tridens:n.a.:TRFL2.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

160

22) Click on the Right-facing Arrow icon to place these species on the User Selected

Plants list.

This completes the Select Plants section.

At the top of the page, click on the Planting Design icon. It may take up to 5 minutes to load.

You will eventually get a table with tabs at the top.

23) On the Plant Material Tab, click the arrow next to seed for field paspalum. Note that

seed is the only option for this species. This is also true for the other two selected

species.

24) Click on the Seeding Calculation Tab.

25) Click the box labeled Acres to Seed.

26) Type 15 in the box.

27) Click the box to the right of Seeding Method.

28) Type 12.0 if it is not already in the box.

29) Click the Mix % cell for field paspalum.

30) Type 40 in the box.

31) Hit the Tab-key

32) The Actual Seeding Rate, Actual Seeds ft2

, & Total Needs will be filled in

automatically.

33) In the Mix % cell for purple lovegrass.

34) Type 30 in the box

35) Hit the Tab-key

36) In the Mix % cell for purpletop tridens.

 (1) Type 30 in the box

 (2) Hit the Tab-key

37) Scroll down and click the Evaluate box.

38) In the Plant Attribute Warring box you will see one Evaluation Result. Click the

Show Attribute box for this Evaluation Result. The Plant Attribute Table displays

the Active Growth Period for each species. If you wish, you can return to the Select

Plants Page and select species with more similar Active Growth Periods. For this

demo, we will not return to the Select Plants Page. Click on OK then click on

Submit.

39) Click on the Site Specification Tab.

40) You can enter various plans and dates for cultural treatments or you can leave this

tab blank.

41) Click on the Planting Specification Tab.

42) You may click on the boxes under Additional Planting Specifications to specify

seed or propagule treatments, change the method of seeding and change planting

dates.

You have now completed VegSpec. You may now look at the Reports that are produced. Click

on Reports at the top of the page. The VegSpec reports present: 1) the soil and climate

information, which corresponds to the project site; 2) the planting objectives; 3) a list of both

potential and selected plant species and cultivars; 4) the seeding and vegetative propagule

rate calculations; 5) the site specific cultural treatments and information about each

treatment; 6) the planting specifications and information about planting methods. After

viewing the combination report, you can print it using the print function of your browser. This
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

161

completes VegSpec.

VEGSPEC Development

Currently, VegSpec development is directed by an interagency steering committee, with members

from USGS, NRCS and the U.S. Army Corps of Engineers. Plans for future VegSpec

development include:

43) PRISM (Parameter-evaluation Regressions on Independent Slopes Model) was developed at

Oregon State University, and is a hybrid statistical-geographical approach to mapping

climate. Our plan is to incorporate PRISM Climate Mapping Project data into VegSpec. This

will enable VegSpec to interpolate climates for regions that are far from climate stations. This

is critical for the mountainous regions of the western U.S.

44) Add plants to the VegSpec library, which are appropriate for Hawaii/Pacific Islands, Alaska

and the US Protectorates.

45) Add practices and plants, which will enable VegSpec users to select plants for wetland

restoration, riparian area restoration, fire rehabilitation, mined-land reclamation,

phytoremediation, wildlife habit and forage enhancement, reclamation of roadways,

landscaping, and conservation buffers.

46) Add an invasive species module. This module will enable VegSpec to recommend native

plants for competitiveness with invasive species, provide information on invasive species

control, and provide site-specific warnings of possible invasive species.

47) Incorporate GIS capability into VegSpec. This would enable VegSpec users to zoom in on an

aerial image of a site by clicking on a series of maps and orthophoto quadrangles. VegSpec

would automatically select the soil and climate station for the re-vegetation project from

information, which is linked to the aerial image.

48) Assign plant native origin by state, county and region.

49) Link plant species to a list of vendors.

The VegSpec World Wide Web address is http://plants.usda.gov, in the Plant Tools box click

VegSpec
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

162

DNA Marker Variation Within and Among Populations of Native and

Commercial Little Bluestem

David R. Huff1, Antonio J. Palazzo2, Martin van der Grinten3, and Thomas Lent4

Abstract

Little bluestem [Schizachyrium scoparium (Michx.) Nash var. scoparium] is a native, warm-season,

perennial bunchgrass that ranges throughout much of the central plains grasslands and the

eastern temperate forests. As a native species, little bluestem is increasingly being used for

restoration projects to enhance the biodiversity of locally disturbed sites. However, a question of

concern arises: "Are commercial seed sources, originating from the central plains region,

genetically appropriate to replace northeast native populations in restoration projects?" In this

study, 60 random amplified polymorphic DNA (RAPD) markers were used to provide estimates of

the comparative genetic variation within and among 30 populations of little bluestem. The 30

populations included: 13 northeast natives, 9 south-central Canadian natives, five commercial

cultivar sources, two central plains land races, and one vegetative source used for restoration.

Genetic distances, calculated among all individuals, were analyzed using the analysis of molecular

variance (AMOVA) technique. Even though most genetic variation resided within populations, four

distinct groupings of the 30 populations were apparent, namely: 1) 11 of the 13 northeastern

natives 2) the plains-type (including all mid-west commercial cultivar sources, land races, and

Canadian populations), 3) the Ohio population, and 4) a class of very different material containing

the western PA population and the Cape May Plant Material Center vegetative selection. These

results suggest that northeast native populations are genetically distinct from populations of the

remaining groups and thus, the procurement of seed stock for northeast restoration projects

becomes more difficult. In addition, genetic distance and geographic distance were observed to

be correlated among northeast populations. However, the high amount of genetic variability

observed within populations of little bluestem should aid in the construction of genetically broadbased materials useful for restoration efforts, in the event that local sources are no longer

available.

 

1 Dep. of Agronomy, Pennsylvania State University, University Park, PA 16802; 2 U.S. Army Cold

Regions Research and Engineering Laboratory, Hanover, NH 03755; 3 USDA, NRCS, Big Flats

PMC, Corning, NY 14830; 4 US Army, Fort Drum, NY.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

163

Extraction and Germination Ecology of Twelve Native Grasses from

Western North Carolina

Robert P. Karrfalt1

The National Forests in North Carolina working in cooperation with the National Park Service, the

Blue Ridge Parkway, collected 31 seedlots of native grasses representing 12 native grass

species (Tables 1). The National Tree Seed Laboratory agreed to extract, clean, and test the

seed lots. Germination conditions were not established for some of the species, and the

possibility existed that because they were collected from high elevation, that established

prescriptions might not be appropriate.

Methods

The lots were hand collected in the fall of 1998. After an initial drying period they were

transported to the National Tree Seed Laboratory for cleaning and testing. Extraction was with

the Westrop Brush Machine. Some lots were hand screened to remove a few stems. All lots

were then aspirated in a custom built aspirator with fine air speed control and a 12 inches wide

vibratory feeder. This aspirator gave relatively high volume output of clean seed even on small

seeded species.

Cleaned seed lots were tested for moisture content using from 0.010 to 0.060 grams of seeds,

depending on the species. The ISTA oven method (ISTA 1999) was used except for the smaller

weight used to conserve seeds. Grinding is required also in the ISTA rules for grasses, but this

was not practical with the small weight tested. Therefore, whole seeds were used.

Radiographs were made of all seed lots to determine that they all had high percentage of seeds.

Germination tests were made under five temperature combinations: constant 15, 20, and 25o

 C,

alternating 15-25o

C, and 20-30oC. When the number of seeds was limited, two treatments of a

constant 20 and 15-25 temperature were used. The cool temperature was for sixteen hours and

the warm treatment for eight hours except for 15-25o

C which on the weekends was kept at a

constant 15o

 C. Light was supplied for either 8 or 16 hours. When darkness was used the seeds

were placed inside a light proof envelope. Dark treatments were exposed to the normal light in

the germinator during germination counts. Light was at 100+ foot-candles from cool white

fluorescent lamps. Prechill was for 21 days. Half of the seeds of each lot were prechilled while

half were not. Four ten-seed replications were planted for each treatment combination. Each

replication was randomly assigned a position in the germinator. Blue blotters, the germination

media, were placed in plastic petri dishes in sandwich bags to prevent moisture loss and avoid

the need to add water to the dishes after planting. Prechill was accomplished by planting the

seeds and placing the bagged dish in the cold room. Figure 1. shows the treatment combinations.

Germination counts were made at weekly intervals beginning at 7 days and ending at 28 days.

Tests were planted beginning in June of 1999, and completed in August 1999.

Results

Although this experiment was designed for response surface analysis to identify the optimal

conditions for seed germination, the analysis could not be completed in time for publication of this

Proceedings. Therefore, general observations are given based on inspection of the data and

means (table 1.). Light appeared to be beneficial in all species to some degree. The effect was

greater for some species than for others. In a few cases the 16-hour period appears to be poorer

than the 8 hours, but this is probably more the effect of the germination temperature used with the

16 hours of light rather than the photoperiod. Germination without light was common in many of

the lots. On the average, however, thew percentage of seed germination in the light was

 

1

 National Tree Seed Laboratory, Rt 1, Box 182B, Dry Branch, GA 31020
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

164

observed to be higher than in the dark. Prechill gave positive results with six species:

Andropogon gerardii Vitman, Danthonia spicata (L.) P. Beauv. ex Roem. & Schult., Panicum

virgatum L, Schizachyrium scoparium (Michx.) Nash, Sorghastrum nutans (L.) Nash, and Tridens

flavus (L.) Hitchc. Some of the lots of Deschampsia flexisoa (L.) Trin. and Elymus virginicus L.

may have shown a response to prechill. Therefore, these eight species will be treated with

prechill in future tests to make a firm determination of their dormancy. In some cases germination

in the dark appeared to be facilitated by prechill. This effect was seen in Sorghastrum nutans,

Festuca rubra L. and Elymus virginicus.

Conclusions

Four of these species are listed in the Rules of Testing Seeds (AOSA 1998). These species are

Andropogon gerardii, Panicum virgatum, Schizachyrium scoparium, and Sorghastrum nutans.

Since the seed lots reported on here are from high elevations in the southern Appalachian

Mountains, they might have different germination conditions from the Great Plains seed sources

which are the likely source of seeds on which the rules were based. It would appear from this

data that any differences are not large, if they exist at all. More study will be needed to identify

the optimum conditions for seed germination as this data only provides an initial screening.

However, an observed optimum test prescription is listed in table 2 for each species tested. This

optimum was based on trends in the data and what combination gave the highest germination.

As the samples were small, table 2 should only be viewed as a starting point. Further tests with

larger seed samples hopefully will be done to delineate what the exact germination conditions

should be. Light will be used on all future tests. Prechill will be used were it clearly or possibly

had an effect as listed in table 1. Future tests will use the optimums listed in table 2 as starting

points on the response surface

Figure 1. Matrix of germination treatment combinations. Treatments that were used are marked

with a “X.” Treatments used when the number of seeds was limited are marked with a “S”.

Temperature 15 20 25 15-25 20-30

No prechill

16 hours light X X S X

8 hours light X X S X S X

Dark X X S X X S X

Chill 21 days

16 hours light X X S X

8 hours light X X S X S X

Dark X X S X X S X
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

165

Table 1. Observed seed lot means showing the effect of prechill and light.

Species Prechill Hours of light

Lot # None 21 days 0 8 16

Andropogon gerardii Vitman 1 2 6 3 46

Bromus pubescens Muhl. ex Willd. 1 61 60 38 78 55

2 39 37 30 46 43

3 58 58 39 68 79

4 40 42 33 45 49

5 34 33 4 53 55

Danthonia spicata (L.) P. Beauv. ex Roem. &

Schult.

1 30 56 17 66 58

Deschampsia flexuosa (L.) Trin. 1 37 44 27 53 50

2 64 63 61 69 62

3 35 33 31 38 36

4 54 49 51 58 46

Elymus hystrix L. 1 69 58 45 94 40

2 51 36 35 60 38

Elymus virginicus L. 1 42 42 12 68 51

2 67 76 58 84 83

3 14 28 9 33 21

4 25 27 19 35 23

5 53 43 41 59 40

Festuca rubra L. 1 67 63 73 53 74

2 5 6 5 65

Panicum virgatum L. 1 0 2 0 40

Saccharum alopecuroideum (L.) Nutt. 1 8 9 4 15 8

2 28 30 19 45 27

3 23 17 15 24 25

4 16 12 5 25 17

Schizachyrium scoparium (Michx.) Nash 1 1 5 1 55

Sorghastrum nutans (L.) Nash 1 10 20 12 20 16

Tridens flavus (L.) Hitchc. 1 6 22 2 35 7

2 0 19 1 23 7

3 0 18 0 22 0

4 1 28 6 28 9

5 0 26 3 26 14
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

166

Table 2. Estimated optimal germination conditions. (These should not be taken as proven best.)

Species Prechill

days

Light

Hrs

Temperature Highest

Observed

Germination

Andropogon gerardii Vitman 21 8 20 15

Bromus pubescens Muhl. ex Willd. 0 8 20,20-30,

15-25

93

Danthonia spicata (L.) P. Beauv. ex

Roem. & Schult.

21 8 15-25 100

Deschampsia flexuosa (L.) Trin. 21 8 20-30 85

Elymus hystrix L. 0 8 15-25 78

Elymus virginicus L. 21 8 15-25 90

Festuca rubra L. 0 8 20 83

Panicum virgatum L. 21 8 20-30 15

Saccharum alopecuroideum (L.)

Nutt.

21 8 15-25 63

Schizachyrium scoparium (Michx.)

Nash

21 8 15-25 10

Sorghastrum nutans (L.) Nash 21 8 15-25 40

Tridens flavus (L.) Hitchc. 21 8 15-25 98

References

AOSA. 1998. Rules for Testing Seeds. Association of Official Seed Analysts, Inc., Lincoln,

Nebraska

ISTA. 1999. International Rules for Seed Testing Rules 1999. Seed Science and Technology

27(Supplement)
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

167

Simulating Biomass/Forage Production of Eastern Gamagrass,

Switchgrass, and Other Warm Season Grasses

J. R. Kiniry1, H. Sanchez2, J. Greenwade3, E. Seidensticker4,

J. R.Bell5

, F. Pringle5, G. Peacock Jr.6, and J. Rives7

A robust model capable of realistically simulating range productivity would be valuable for a

variety of applications. It could be used to compare soil erosion rates for row cropping systems

with different perennial forages. Such a model could help answer water quality questions

downstream from such production systems. The model could be used to look at effects of

changes in CO2 levels and changes in temperature and rainfall on range productivity. With

adequate parameters for different grass species, the model could be used to compare

productivity of communities composed of native grass species with productivity of improved

pastures. Finally, such a model could be used to simulate changes in soil erosion and range

productivity in response to overgrazing or invasion by woody species.

The ALMANAC model (Kiniry et al. 1992b) holds promise for such applications. The model was

used to simulate Alamo switchgrass productivity at several locations in Texas (Kiniry et al.

1996). The model simulates plant growth using leaf area index (LAI) and radiation use efficiency

(RUE). The model can simulate several plant species competing for light, water, and nutrients.

The soil inputs can be easily derived from the NRCS Soils 5 Data Base. Required inputs, daily

maximum and minimum temperatures, solar irradiance, and rainfall are readily available from

many sites.

With these potential applications in mind, the objective of this study was to demonstrate the

capability of the ALMANAC model to dynamically simulate range productivity in five regions of

Texas, with multiple soils in each region. Fifty year simulations were compared to published

range productivity values for the soils in each region. Texas, with its diverse rainfall and

temperature zones, varies widely in range productivity. The state’s differences in rainfall, air

temperature, relative humidity, and soils offer excellent environmental conditions for testing

simulation models.

Methods

General Model Description

The ALMANAC model simulates water balance, nutrient balance, and interception of solar

radiation. This model includes subroutines and functions from the EPIC model (Williams et al.

1984; Williams et al. 1989) with added details for plant growth. The model has a daily time step.

It simulates plant growth reasonably well and is implemented easily.

Light Interception

ALMANAC simulates light interception by the leaf canopy with Beer’s law (Monsi and Saeki 1953)

and the LAI. The greater the value of the extinction coefficient k, the more light will be intercepted

at a given LAI.

The fraction of incoming solar radiation intercepted by the leaf canopy is

 

1

 USDA-ARS, 808 E. Blackland Rd., Temple, TX 76502; 2USDA-NRCS, W.R.Poage Federal

Bldg., 101 South Main Street, Temple, TX 76501; 3

USDA-NRCS, 7300 North IH-35, Temple, TX

76501; 4

USDA-NRCS, 7705 W. Bay Road, Baytown, TX 77520; 5USDA-NRCS, 6565 Amarillo

Blvd. West, Suite A, Amarillo, TX 79106; 6

USDA-NRCS, Forth Worth, TX; 7USDA-NRCS, 501 S.

Cypress, Pecos, TX 79772.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

168

Fraction = 1.0 - exp (-k * LAI) (1)

We derived k values for several grass species in field plots at Temple (Kiniry et al. 1999).

Leaf Area Development

Accurate prediction of light interception depends on realistic description of leaf area. Values for

LAI development were from measurements on plots at Temple (Kiniry et al. 1999). ALMANAC

simulates decreases in LAI due to plant density. Plant stand was estimated for the two most

common grass species for each soil at each site.

Simulation of light interception also requires accurate description of leaf area production and

decline. The model estimates leaf area production up to the point of maximum leaf area for the

growing season using Eq(2). The model generates a curve that is forced through the origin and

through two points, asymptotically approaching y=1.0. The s-curve function takes the form:

F = X / (X + exp (Y1 - Y2 * X)) (2)

where F is the factor for relative LAI, X is the fraction of heat units from planting to maturity, and

Y1 and Y2 are the s-curve coefficients generated by ALMANAC. For each day, the fraction of

total heat units that have accumulated is determined, denoted as SYP. The sum of heat units is

zero at planting in the establishment year and at tiller emergence in subsequent years, and is

maximum at maturity. The s-curve describes how LAI can increase, under nonstress conditions,

as a function of SYP.

Loss of leaf area late in the season is described with the LAI decline factor (RLAD). This occurs

after an input fraction (XDLAI) of heat units for the season has accumulated. Three equations

describe how leaf area (SLAI) declines late in the season:

XX = log10[(1.001 - SYP)/(1.0 - XDLAI)] (3)

RTO = RLAD * XX (4)

where RTO is constrained to be greater than or equal to -10.0, and

SLAIt = Minimum of (SLAIt-1 and SLAIO * 10RTO) (5)

where t is the current day, t-1 is the previous day, and SLAIO is the SLAI on the day before leaf

area begins to decrease.

Biomass Production and Partitioning

Biomass growth is simulated with a RUE approach (Kiniry et al. 1989). Values for RUE have

been derived for wheat [Triticum aestivum L.], rice [Oryza sativa L.], maize [Zea mays L.], and

sorghum [Sorghum bicolor (L.) Moench] (Kiniry et al. 1989), for potato [Solanum tuberosum L.]

(Manrique et al. 1991), and for sunflower [Helianthus annuus L.] (Kiniry et al. 1992a). For

grasses, we used values derived at Temple (Kiniry et al. 1999).

The decline in RUE in later growth stages is described with an identical function to the one for the

decrease in LAI but with different input values.

The maximum rooting depth defines the potential depth in the absence of a root-restricting soil

layer. Soil cores from the plots at Temple in 1994 indicated that some grass roots extended to

2.2 m.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

169

Model Evaluation

Data Sets

We tested ALMANAC on a total of 20 soils, from a diverse set of regions in Texas (Tables 1 and

2). Appropriate soil parameters were used and the weather data was the measured daily

maximum and minimum air temperatures, and rain from the nearest weather station. Distances

between weather stations and yield plots are especially important for rain data.

Population densities and grass species used were based on the reported species composition for

each soil in the soil surveys.

 

Soils at the sites differed in their capacity to store water (Table 2). Soils with the highest plant

available water (PAW) in the profile at field capacity were the Houston Black, Nuff, Topsey, and

Pullman. Potter, Doss, Tivoli, Brewster, Delnorte and Santo Tomas had the lowest PAW at field

capacity.

Table 1. Texas data sets used in range simulations.

Region Counties

Lat./Long.

N, W

degrees/min

Weather

Station MLRAH

Mean

Annual

RainI

mm

East Texas

Central Texas

High Plains

West Texas

Coastal Region

Kaufman

Coryell

Bell

Moore

Potter

Jeff Davis

Reeves

Reeves

Chambers

32.36/96.18

31.06/97.20

35.14/101.49

31.26/101.30

30.19/104.01

31.00/103.40

29.46/94.41

Wills Point

Temple

Amarillo

Pecos

Marfa

Balmorhea

Anahuac

86A, 87A

85, 86A

78A

42

42

42

150B

1050

794

444

221

329

294

1189

H

Major land resource areas

I

Average for the sixty simulated years

The model was evaluated by addressing the following questions:

1. Could the model simulate the mean expected productivity for a soil at

a site using 50 years of weather data?

2. For each soil at each site, how well did simulated yields for high rainfall and low rainfall years

compare to reported productivity values for favorable and unfavorable years?

Results and Discussion

ALMANAC realistically simulated differences among soils in range productivity (Table 3). Mean

simulated yields were within 0.3 t ha-1 of mean reported yields for all soils except Reakor,
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

170

Balmorhea and Harris. The model also reasonably simulated yields on “good” and “poor” rainfall

years.

ALMANAC shows promise as a tool for decision making with grasses in diverse environments on

a diverse range of soils. The data sets developed here can be used as starting points to derive

data sets for sites with similar soils and weather, providing users with examples of realistic values

for soil and plant parameters.

Models and data sets described herein are available to users at no charge. Users wanting these

models and data should send three 1.44 MB diskettes to the senior author.

Table 2. Range Data Sets in Texas. PAW is the plant available water; the difference between

the drained upper limit and the lower limit for the profile. Runoff curve numbers are

based on soil hydrologic groups.

Region Soil Type

Soil Depth

m

PAW

cm

Runoff Curve

Number

East Texas

Central Texas

Central Texas

Central Texas

Central Texas

Central Texas

High Plains

High Plains

High Plains

High Plains

High Plains

High Plains

High Plains

West Texas

West Texas

West Texas

West Texas

West Texas

Gulf Coast

Gulf Coast

Crockett

Houston Black clay

Topsey

Brackett

Doss

Nuff

Potter

Pullman

Tivoli

Amarillo

Mobeetie

Spur

Sweetwater

Santo Tomas

Delnorte

Brewster

Reakor

Balmorhea

Lake Charles

Anahuac

2.03

1.89

2.03

0.86

0.46

2.03

0.23

2.03

1.52

1.00

1.52

1.50

1.52

1.91

1.52

0.20

1.50

1.52

2.03

1.52

22

26

29

12

7

32

2

26

8

12

14

22

16

8

4

1

25

22

23

21

80

80

80

80

80

80

80

80

39

80

61

80

80

61

80

61

61

74

80

80
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

171

Table 3. Annual range productivity with good, average, or poor rainfall conditions.

Range Site Soil Yields t ha-1

Good Average Poor

Central Texas Blackland Houston

black

NRCS

Simulated

7.0

6.9

6.0

5.9

3.5

4.5

 Clay loam Topsey NRCS

Simulated

6.5

5.7

5.0

4.9

3.0

4.2

 Adobe Brackett NRCS

Simulated

4.0

3.7

3.2

3.2

1.8

2.7

 Shallow Doss NRCS

Simulated

4.0

3.1

3.0

2.7

1.8

2.4

 Stony clay loam Nuff NRCS

Simulated

5.5

5.5

4.5

4.4

2.5

3.1

High Plains Very shallow Potter NRCS

Simulated

0.8

0.8

0.7

0.5

0.4

0.3

 Deep hardland Pullman NRCS

Simulated 21

2.0

1.5

1.5

0.9

1.0

 Sand hills Tivoli NRCS

Simulated

2.2

2.0

1.6

1.6

1.4

1.2

 Sandy loam Amarillo NRCS

Simulated

2.3

2.0

1.6

1.5

1.2

1.0

 Mixed slopes Mobeetie NRCS

Simulated

2.7

2.6

2.0

2.0

1.4

1.5

 Loamy bottomland Spur NRCS

Simulated

3.9

3.6

2.6

2.5

1.8

1.7

 Wet bottomland Sweetwater NRCS

Simulated

5.6

6.4

4.3

4.0

3.0

1.9

East Texas

 Claypan prairie

Crockett NRCS

Simulated

6.0

5.9

5.0

5.1

3.0

4.3

West Texas

 Igneous hill and mountain Santo Tomas

NRCS

Simulated

1.3

1.3

1.1

1.1

0.9

0.9

 Gravely desert

 Grassland

Delnorte NRCS

Simulated

0.8

1.0

0.5

0.5

0.3

0.1

 Mixed prairie Brewster NRCS

Simulated

1.4

1.7

1.1

1.0

0.8

0.4

 Desert grassland Reakor NRCS

Simulated

1.0

1.1

0.8

0.4

0.6

0.1

 Desert grassland Balmorhea NRCS

Simulated

2.2

1.5

1.8

0.6

1.2

0.1

Gulf Coast Blackland Lake Charles NRCS

Simulated

9.0

9.0

7.5

7.5

6.0

5.9

 Firm brackish marsh Anahuac NRCS

Simulated

11.0

10.8

8.3

8.7

5.5

6.5

1

t ha-1 multiplied by 1.009 equals thousands of pounds acre-1
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

172

References

Kiniry, J.R., C.A. Jones, J.C. O’Toole, R. Blanchet, M. Cabelguenne, and D.A. Spanel. 1989.

Radiation-use efficiency in biomass accumulation prior to grain-filling for five grain-crop species.

Field Crops Res. 20:51-64.

Kiniry, J.R., R. Blanchet, J.R. Williams, V. Texier, C.A. Jones, and M. Cabelguenne. 1992a.

Simulating sunflower with the EPIC and ALMANAC models. Field Crops Res. 30:403-423.

Kiniry, J.R., J.R. Williams, P.W. Gassman, and P. Debaeke. 1992b. A general, process-oriented

model for two competing plant species. Trans. ASAE. 35:801-810.

Kiniry, J.R., M.A. Sanderson, J.R. Williams, C.R. Tischler, M.A. Hussey, W.R. Ocumpaugh, J.C.

Read, G. van Esbroeck, and R.L. Reed. 1996. Simulating Alamo switchgrass with the ALMANAC

model. Agron. J. 88: 602-606.

Kiniry, J.R., C.R. Tischler, and G.A. van Esbroeck. 1999. Radiation use efficiency and leaf CO2

exchange for diverse C4 grasses. Biomass and Bioenergy 17: 95-112.

Manrique, L.A., J.R. Kiniry, T. Hodges, and D.S. Axness. 1991. Relation between dry matter

production and radiation interception of potato. Crop Sci. 31:1044-1049.

Monsi, M. and T. Saeki. 1953. Uber den lichtfaktor in den Pflanzengesellschaften und sein

bedeutung fur die stoffproduktion. Japan J. Bot. 14:22-52.

Williams, J.R., C.A. Jones, and P.T. Dyke. 1984. A modeling approach to determining the

relationship between erosion and soil productivity. Transactions of the ASAE 27(1):129-144.

Williams, J.R., C.A. Jones, J.R. Kiniry, and D.A. Spanel. 1989. The EPIC crop growth model.

Trans. ASAE 32:497-511.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

173

Leaf Area Production, Biomass Production, and Biomass Partitioning for

Eastern Gamagrass, Alamo Switchgrass, and Two Other C4 Grasses

J.R. Kiniry1, C.R. Tischler1, and G. A. Van Esbroeck2

Grassland modeling requires knowledge of rate-limiting processes to accurately simulate biomass

growth. Increased understanding of factors controlling grass biomass production will help define

productivity of different grassland communities. Thus, limitations due to stress or due to canopy

architecture and leaf area can be better understood. As part of a project to model grasslands

(Kiniry et al. 1996; Kiniry 1998, Kiniry et al. 1999), we measured several aspects of growth of

Alamo switchgrass [Panicum virgatum L.], eastern gamagrass [Tripsacum dactyloides (L.) L.],

and two other common warm-season grasses (sideoats grama [Bouteloua curtipendula (Mich.)

Torrey] and big bluestem [Andropogon gerardii Vitman]). Traits including leaf area index (LAI),

above-ground biomass, and light interception were measured several times during the three

growing seasons on a deep, Houston Black clay soil near Temple, TX. We also measured root

mass and soil carbon with soil cores at the end of two growing seasons. These measurements

were all designed to quantify leaf area production and biomass growth to assist in computer

simulation of these grasses in diverse environments.

Differences in partitioning to roots and shoots could cause erroneous conclusions when

comparing productivity among species if only the aboveground biomass is measured. Ideally,

productivity should be analyzed in terms of shoots, roots, and soil carbon.

The objective of this field study was to quantify leaf area and biomass growth of four C4 grasses:

sideoats grama, big bluestem, eastern gamagrass, and switchgrass. The LAI and light extinction

coefficients were determined for these species to quantify how efficiently the grasses intercept

light. Root:shoot ratios were measured to assess how these contributed to differences in growth

among species. These results should help modelers focus their efforts on predicting biomass

production at sites dominated by C4 grasses.

Methods

Studies were carried out on four C4 grass species at the Grassland, Soil and Water Research

Laboratory near Temple, TX, on Houston Black clay (fine, montmorillonitic, thermic Udic

Pellustert). Grasses included two separate plots of Alamo switchgrass, Haskell sideoats grama,

and Kaw big bluestem, and Experimental Line 1209 of eastern gamagrass (from Woodward, OK).

Four plots of each species, each plot 5 m by 75 m, were established in 1993. Adequate N was

applied to prevent nutrient stress. Grasses were burned in Feb. each year.

The fraction of light intercepted was measured on seven dates in 1995, six dates in 1996, and six

dates in 1997. Five PAR readings were taken above the canopy, followed by ten below and then

five more above.

Aboveground biomass was harvested on several dates each year, from three 1 m2

 areas for

switchgrass and eastern gamagrass and from three 0.25 m x 0.25 m areas per plot for big

bluestem and sideoats grama. There were seven biomass harvest dates in 1995, six dates in

1996, and five dates in 1997. All samples were dried in a forced-air oven. Leaf and stem area

was determined on the samples harvested destructively.

 

1

USDA ARS, 808 E. Blacklands Road, Temple, TX 76502 and 2Department of Crop Science,

North Carolina State University, Raleigh, NC 27695-8604
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

174

We sampled belowground biomass by taking six 0.041 m diameter cores per plot, three on grass

plants and three between grass plants, on 13 July 1995 and 30 July 1996. Cores were taken for

the entire soil depth. We washed each 0.25 m increment of each core, collected plant material on

a window screen with squares 0.23 mm x 0.23 mm, dried the roots at 651 C for 48 h, and

determined dry mass.

Figure 1. Above-ground biomass per unit area of two areas of eastern gamagrass

Soil organic carbon was determined with cores of the same diameter, taken to 1 m depth on 30

Aug. 1995 and for the entire soil profile on 20 July 1996. There were six cores 0.5 m apart on a

transect. We also sampled cores on an adjacent cultivated field (in both years) and from a

nearby native prairie (1996 only) for comparison. All six samples from a depth were combined

and ground. Depth increments were 0.10 m in 1995 and 0.25 m in 1996. The roots were

removed by screening. A subsample was then analyzed for organic matter with the modified

Walkley-Black method (Walkley 1947).

Results

In 1995, plots received adequate rainfall to avoid drought stress during the growing season.

However, rainfall after July 1995 was insufficient to refill the soil profile. This resulted in drought

stress during the 1996 growing season, as evidenced by leaf rolling, especially for eastern

gamagrass and switchgrass. This caused a shorter period of active growth in 1996. Rainfall was

greatest in 1997 and plants did not suffer from drought stress.

Eastern gamagrass

Day of Year

100 150 200 250

Dry Weight (g m-2)

0

400

800

1200

1600

2000

1995

1996

1997
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

175

Figure 2. Above-ground biomass per unit ground area of two areas of switchgrass

Switchgrass had more biomass than the other species throughout the growing seasons (Fig. 2).

Sideoats grama (not shown) had the least biomass and eastern gamagrass (Fig. 1) and big

bluestem (not shown) was intermediate. Final biomass of switchgrass in 1995 and 1997 was

greater than biomass of Alamo switchgrass measured previously at several Texas locations

(Sanderson et al. 1996). These other locations in Texas received 67 or 134 kg N ha-1, less than

the 200 kg N ha-1 in the present study. The maximums in 1995 for Switchgrass 2 and

Switchgrass 1 yields in the present study were 2318 and 3720 g m-2. In 1997 these maximums

were 1903 and 3929 g m-2.

 Similar values for Alamo switchgrass were reported in Auburn, AL

with 2439 g m-2 for an Aug. 1990 harvest and 3696 g m-2 for the total 1990 production (Sladden et

al. 1991).

Leaf area index (LAI) values were usually greatest in 1995 and 1997 (Fig. 3 & 4). In these two

years, maximum LAI values were 17.7 and 15.7 for Switchgrass 1, 12.9 and 11.1 for Switchgrass

2, and 1.7 and 1.6 for sideoats grama. In these two years, eastern gamagrass had maximums of

4.3 and 4.8 and big bluestem had 7.7 and 7.6. The big bluestem maximums were similar to

values of 5.8 to 8.0 for “pawnee” big bluestem in two years in Nebraska (Mitchell et al. 1998).

The switchgrass maximums were greater than those in the Nebraska study for “trailblazer”

switchgrass, with maximums of 4.9 and 7.7 in two years.

In the drier year, 1996, maximum LAI values were noticeably lower for switchgrass and big

bluestem. Maximums were 8.1 and 3.4 for switchgrass, 2.4 for big bluestem, 1.5 for sideoats

grama, and 4.2 for eastern gamagrass.

Light extinction coefficients

Pooling data across years, within each species indicates that the light extinction coefficient (k)

was not significantly related to LAI for sideoats grama, switchgrass, or eastern gamagrass (Fig. 5

and 6). Thus, one k value was sufficient for each of these grasses. The means for switchgrass

and eastern gamagrass were similar, 0.33 and 0.31. The mean for sideoats grama was much

greater, 1.05.

Switchgrass 1

100 125 150 175 200

Dry Weight (g m-2)

0

1000

2000

3000

4000

5000

1995

1996

1997

Switchgrass 2

Day of Year

100 125 150 175 200
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

176

Figure 3. Leaf area index of two areas of switchgrass

Figure 4. Leaf area index of three species of grasses.

Switchgrass 1

100 150 200 250

Leaf Area Index

0

4

8

12

16

20

1995

1996

1997

Switchgrass 2

Day of Year

100 150 200 250

Big bluestem

Day of Year

100 150 200 250

Eastern 

gamagrass

100 150 200 250

Sideoats grama

100 150 200 250

Leaf Area Index

0

2

4

6

8

1995

1996

1997
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

177

Figure 5. Light extinction coefficient (k) for Beer’s law for the three species over three years.

Figure 6. Light extinction coefficient (k) for Beer’s law for sideoats grama over three years.

Eastern gamagrass

y=0.36-0.016x

r

2

=0.19

mean k=0.31

02468

Leaf Area Index

0 4 8 12

k 0.0

0.2

0.4

0.6

0.8

1.0

1995

1996

1997

Big bluestem

For LAI<2.5, y=1.09-0.23x

r

2

=0.89

mean k=0.36 for LAI>2.5

0 2 4 6 8 10

Switchgrass

y=0.42-0.015x

r

2

=0.10

mean k=0.33

Leaf A rea Index

0.0 0.5 1.0 1.5 2.0

k

0.0

0.5

1.0

1.5

2.0

1995

1996

1997

S ideoats gram a

y=1.12-0.08x

r2 =0.01

m ean k=1.05
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

178

Big bluestem was the only grass which showed a trend of decreasing k with increasing LAI,

similar to that reported for napier grass [Pennisetum purpureum Schumach.] (Kubota et al. 1994).

However, napier grass k decreased from 1.1 to 0.4 as LAI increased from 2.8 to 15.3. Big

bluestem k decreased only for LAI values less than 2.5. Above 2.5, mean k was 0.36, similar to

switchgrass and eastern gamagrass. The values of k for three of the grasses in the present study

were similar to the 0.3 value reported for grasses by Monteith (1965).

Figure 7. Root mass distribution at different soil depths for eastern gamagrass and big bluestem.

Samples were taken at the end of 1996 and 1997 growing seasons. Line connects the mean

values for each depth. Fraction of Root Biomass

0.0

0.2

0.4

0.6

0.8

1.0

1995

Eastern gamagrass

0 50 100 150 200

0.0

0.2

0.4

0.6

0.8 1996

0 50 100 150 200 250

1995

1996

Big bluestem

SOIL DEPTH (CM)
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

179

Root biomass was measured to compare whole-plant productivity among species. Root biomass

of these species had similar patterns of distribution, with sideoats grama being the shallowest

rooting (Fig. 7 and 8). In 1995 and 1996, sideoats grama had 61 to 68 percent of its total root

biomass in the top 0.25 m of soil and 84 to 85 percent in the top 0.5 m. By comparison, the other

species had 45 to 54 percent in the top 0.25 m in 1995 and 34 to 65 percent at that depth in

1996. For the top 0.50 m the other species had 67 to 77 percent in 1995 and 50 to 84 percent in

1996.

Figure 8. Root mass distribution at different soil depths for sideoats grama and big bluestem.

Samples were taken at the end of 1996 and 1997 growing seasons. Line connects the mean

values for each depth.

The fraction of total plant biomass in the roots was similar between switchgrass and sideoats

grama (Table 1). In 1995, the root:total biomass ratio of sideoats grama was intermediate

between that for Switchgrass 1 and Switchgrass 2. Eastern gamagrass and big bluestem had

ratios greater than 0.50 in this year. Root values were generally greater in the drier, 1996 season

than in 1995. The root:total mass ratios were sometimes doubled relative to the ratio in 1995.

Mean root mass increased in all cases except for Switchgrass 1. Fraction of Root Biomass

0.0

0.2

0.4

0.6

0.8

1.0

1995

Eastern gamagrass

0 50 100 150 200

0.0

0.2

0.4

0.6

0.8 1996

0 50 100 150 200 250

1995

1996

Big bluestem

SOIL DEPTH (CM)
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

180

Table 1. Ratio of root biomass divided by total biomass for the end of the growing seasons in two

years. Values in parentheses are the g of dry root biomass per m2

 ground area.

1995 (3rd Season) 1996 (4th Season)

Sideoats grama 0.35 (390) 0.60 (635)

Switchgrass 1 0.37 (2142) 0.73 (1384)

Switchgrass 2 0.30 (978) 0.60 (1853)

E. gamagrass 0.62 (1473) 0.81 (2290)

Big bluestem 0.53 (1134) 0.83 (1654)

Soil carbon is a possible site where carbon losses could differ among grass species. However,

carbon was not lost to the soil as organic carbon to a greater extent for sideoats grama than for

switchgrass (Table 2). The mean for sideoats was intermediate to the two switchgrass plots in

1995 and lower than the two switchgrass plots in 1996. In 1995, all grass plots means were

greater than the mean for an adjacent area that had been in continuous cultivation with row

crops. The nearby native prairie had the highest organic carbon.

Table 2. Soil organic carbon concentration (by weight). Values are for four cores per replication,

with 13 to 14 July sampling in 1995 and 15 July sampling in 1996. Soil cores were taken to 1.0 m

in 1995 and to 1.5 m in 1996. No SE is shown when only one replication was sampled.

Switchgrass 1 and Switchgrass 2 are different plots of switchgrass.

Mean +\- SE

Percent

Mean/Sideoats

mean

1995

Sideoats grama 1.10 1.00

Switchgrass 1 1.15 1.04

Switchgrass 2 1.03 0.94

E. gamagrass 1.04 0.95

Big bluestem 0.95 0.86

Cultivated field 0.83 0.76

1996

Sideoats grama 0.72 +\- 0.04 1.00

Switchgrass 1 1.15 1.60

Switchgrass 2 0.79 +\- 0.06 1.10

E. gamagrass 0.73 1.01

Big bluestem 0.79 +\- 0.05 1.10

Cultivated field 0.90 1.25

Native prairie 1.22 1.69

Conclusions

With the exception of switchgrass, the biomass and LAI values of the grasses we studied were

similar to values reported in the literature for other grasses. Differences among species in

biomass production were not related to partitioning between roots and shoots, or soil organic

carbon.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

181

References

Kiniry, J.R., M.A. Sanderson, J.R. Williams, C.R. Tischler, M.A. Hussey, W.R. Ocumpaugh, J.C.

Read, G. van Esbroeck, and R.L. Reed. 1996. Simulating Alamo switchgrass with the ALMANAC

model. Agron. J. 88: 602-606.

Kiniry, J.R. 1998. Biomass accumulation and radiation use efficiency of honey mesquite and

eastern red cedar. Biomass and Bioenergy 15: 467-473.

Kiniry, J.R., C.R. Tischler, and G.A. van Esbroeck. 1999. Radiation use efficiency and leaf CO2

exchange for diverse C4 grasses. Biomass and Bioenergy 17: 95-112.

Kubota, F., Y. Matsuda, W. Agata, and K. Nada. 1994. The relationship between canopy structure

and high productivity in napier grass (Pennisetum purpureum Schumach.). Field Crops Res.

38:105-110.

Mitchell, R.B., L.E. Moser, K.J. Moore, and D.D. Redfearn. 1998. Tiller dynamics and leaf area

index of four perennial pasture grasses. Agron. J. 90:47-53.

Monteith, J.L. 1965. Light distribution and photosynthesis in field crops. Ann. Bot. 29:17-37.

Sanderson, M.A., R.L. Reed, S.B. McLaughlin, S.D. Wullschleger, B.V. Conger, D.J. Parrish, D.D.

Wolf, C. Taliaferro, A.A. Hopkins, W.R. Ocumpaugh, M.A. Hussey, J.C. Read, and C.R. Tischler.

1996. Switchgrass as a sustainable bioenergy crop. Bioresource Technol. 56:83-93.

Sladden, S.E., D.I. Bransby, and G.E. Aiken. 1991. Biomass yield, composition and production

costs for eight switchgrass varieties in Alabama. Biomass and Bioenergy. 1:119-122.

Walkey, A. 1947. A critical examination of a rapid method for determining organic carbon in soils:

effect of variations in digestion conditions and of inorganic soil constituents. Soil Sci. 63: 251-264.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

182

Comparative Germination of 1998 and 1999 Lots of Germtec IITM

Treated Eastern Gamagrass Seed after 28 Days

in the Greenhouse and Laboratory

Donald T. Krizek1, Mary J. Camp2, Susan R. Maxon3, Gwen C. Meyer4,

Jerry C. Ritchie5

, Kathleen M. Davis4, and Miguel L. McCloud1

Abstract

Preliminary greenhouse studies conducted in 1998 indicated that Germtec IITM primed seed of

eastern gamagrass [Tripsacum dactyloides (L.) L.] kept at 4o

C showed a decline in germination

within 2 months after receiving the seed. The experiment was repeated during 1999 in

greenhouses using both 1998 and 1999 seed lots. Three trays of 100 seeds each from both lots

were planted at each location every 4 weeks from March 17 to September 2, 1999. Three

germination tests were also conducted on identical dates in April, July, and September in a

germinator at a day/night temperature of 30/20o

C (8 h photoperiod), using 8 replicates of 50

seeds each. Results indicated that overall there was no significant difference in initial percentage

germination in the greenhouse between the two seed lots, but that over time, there were

significant differences. Both groups showed a similar pattern, with high initial percentage

germination and then a gradual decline. The average 28 d percentage germination values in the

greenhouses for the two seed lots on April 14, May 12, June 9, July 7, August 5, September 2

and September 30, 1999 were 65%, 38%, 44%, 31%, 34%, 37%, and 37%, respectively. The

comparable 28 day percentage germination values in laboratory tests on May 12, July 7, and

September 30 were 67%, 66% (plus 7% dormant), and 64% (plus 7% dormant), respectively, for

the 1998 seed lot and 76%, 72% (plus 11% dormant), and 67% (plus 11% dormant), respectively

for the 1999 seed lot. Tetrazolium chloride tests indicated that the 1998 seed lot had a

significantly greater percentage of dead seed than the 1999 seed lot. The decline in germination

of Germtec IITM treated seed in both seed lots in 1999 is consistent with the pattern observed in

1998 and suggests that: (1) the stimulatory effects of this treatment are relatively short-lasting;

and (2) secondary dormancy may be induced during late spring, and this dormancy may be

broken during subsequent cold storage. The 5-10% variation in percentage germination of this

species at any one date is consistent with previous observations made by NRCS researchers in

Kansas over a 25-year period.

Introduction

Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a native, warm-season, perennial bunch

grass, 2-3 meters tall, that is found in natural grassland prairies of the central, eastern, and

northeastern United States along swales, stream banks, and other lowland sites (Fick 1993;

Dickerson et al. 1997; Row 1998a). It grows from the East Coast to Western Kansas and from the

southern U.S. to upper New York (Beitelspacher 1998). The desirable attributes of this species

have been widely described (Anderson 1990; Beitelspacher 1998; Magoffin 1843; Fine et al.

1990; Foy 1997; Foy et al.1999; Rechenthin 1951; Tian et al. 1997).

Eastern gamagrass is used for livestock forage (Aiken 1997; Aiken and Springer 1998; Brejda et

al. 1997; Coblentz et al. 1998; Horner et al.1985; Wright et al. 1983), wildlife food and cover

 

1

Climate Stress Laboratory, Natural Resources Institute, Agricultural Research Service, U. S.

Dept. of Agriculture, Beltsville, MD 20705; 2

Biometrical Consulting Service, Agricultural Research

Service, U.S. Dept. of Agriculture, Beltsville, MD 20705; 3Seed Regulatory and Testing Branch,

Livestock and Seed Program, Agricultural Marketing Service, U. S. Dept. of Agriculture, Beltsville,

MD 20705; 4

National Plant Materials Center, Natural Resources Conservation Service, U. S.

Dept. of Agriculture, Beltsville, MD 20705; 5

Hydrology Laboratory, Natural Resources Institute,

Agricultural Research Service, U. S. Dept. of Agriculture, Beltsville, MD 20705.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

183

(Dickerson et al. 1997), erosion control (Dabney et al. 1999; Dewald et al.1996; Kemper et al.

1992; Ritchie et al.1997), wetland and upland planting, and native plant community restoration. It

also has the potential for use in carbon sequestration (Kemper et al. 1997) and for biomass

production for fuel. Early reports indicate that it was the mainstay of the American bison but

became nearly extinct through overgrazing (Beitelspacher 1998; Polk and Adcock 1964;

Rechenthin 1951). It flourishes in acid, Al-toxic soils that are severely restricting to most crop

plants (Foy 1997; Foy et al.1999). Because of aerenchyma cells in their roots, eastern

gamagrass plants penetrate waterlogged soils early in the spring, and this provides a source of

needed moisture during much of the summer (Clark et al. 1998; Kemper et al. 1997).

Two obstacles to widespread adoption of eastern gamagrass as a forage plant are erratic

germination and severe weed competition that often result in poor stand establishment (Row

1998a). Problems in metering the seed are also sometimes experienced. Like many warm

season grasses, eastern gamagrass has severe seed dormancy problems which must be

overcome to get a successful stand established (Row 1998a; Knapp 2000; Tian et al. 1997).

The basis of this dormancy is not completely understood but appears to involve both

morphological and physiological barriers (Toole et al. 1956). Various techniques have been used

to break seed dormancy in eastern gamagrass (Ahring and Frank 1968; Anderson 1985, 1990;

Kindiger 1994; Knapp 2000; Row 1998a; Tian et al. 1997) and other warm season grasses

(Knapp 2000; Simpson 1990; Tian et al. 1997; Tischler et al. 1994). One of the main methods

employed is the use of moist pre-chill treatment for 6 to 8 to 10 weeks prior to planting (Dewald

1993; Gamagrass Seed Co. 1999). While excellent results have been obtained using this

procedure, the difficulty is that the seeds must be planted shortly after being received since they

will start to sprout. Recently, a proprietary priming process referred to as Germtec IITM has been

developed by Gamagrass Seed Company. The advantage of this treatment is that the seeds do

not require refrigeration since they are stable at room temperature.

Preliminary greenhouse studies conducted in 1998 indicated that Germtec IITM primed seed of

eastern gamagrass stored at 4o

C showed a decline in germination within 2 months after the seed

was received. The objective of the present study was to compare the germination responses of

1998 and 1999 seed lots of eastern gamagrass given a proprietary seed priming treatment

(Germtec IITM) after 28 days under greenhouse and germinator conditions.

Materials and Methods

Plant material. Seed consisted of 1998 and 1999 lots of eastern gamagrass seed given a

proprietary priming treatment (Germtec IITM) by Gamagrass Seed Co. The 1998 seed lot was

harvested in 1997 and was shipped in February 1998; the 1999 seed lot was harvested in 1998

and was shipped in March 1999. Both seed lots were stored in a cold room (4o

C and 40% RH) at

the Natural Resources Conservation Service (NRCS) Plant Materials Center in Beltsville, MD.

The total percentage germination plus dormant seed for these lots labeled by the dealer was 93

and 85%, respectively (including the dormant fraction).

Location and dates of study. Experiments were conducted in three locations at the Beltsville

Agricultural Research Center (BARC) - two greenhouses, Agricultural Research Service (ARS)

and NRCS; and an Agricultural Marketing Service (AMS) laboratory germinator. Lots of 100

seeds were weighed just before planting. Tests were run on concurrent dates at each location

even though the number of tests varied somewhat between locations. To determine time-course

differences in germination responses in the greenhouse, seeds were planted at seven dates

beginning on March 17, 1999 (DATE 1), and thereafter on April 14 (DATE 2), May 12 (DATE 3),

June 9 (DATE 4), July 8 (DATE 5), August 5 (DATE 6), and September 2 (DATE 7). Germinator

studies were begun on three dates (April 14, July 8, and September 2).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

184

Experimental design. There were three replicates of 100 seeds for each seed lot in the

greenhouse studies and eight replicates of 50 seeds for the germinator studies. For the

greenhouse studies, plastic trays were filled with a peat-vermiculite mix (Jiffy Mix, Jiffy Products

of America, West Chicago, IL) and seeds were planted in five rows of 20 seeds each using a

specially made dibble to ensure that all seeds were planted at a uniform depth of 3.2 cm. For the

germinator studies, seeds were placed on top of two layers of 15 x 23 cm (6 x 9 inch) moistened

blue blotter paper in covered plastic boxes.

Environmental conditions. To standardize germination conditions in the greenhouse, trays were

placed on thermostatically controlled propagating mats (Pro-Grow Supply Corp., Brookfield, WI)

maintained at 30o

C with a GC-1 Gro-Control Thermostat. Dial thermometers were calibrated and

inserted into each tray to monitor soil temperatures and to provide a basis for adjusting the

thermostatic controls. Air temperature in the greenhouse was maintained at a minimum of 27o

C.

A 16 hr photoperiod was maintained by means of supplemental incandescent lamps to provide a

16 hr daylength. Environmental conditions in the germinator consisted of an alternating 30/20o

C

day/night temperature and an 8 hr photoperiod provided by cool white fluorescent lamps.

Although testing guidelines call for addition of 0.2% KN03 (Chirco and Turner 1986), distilled

water was used because of the Germtec IITM treatment. Relative humidity in the germinator was

maintained at ca.100%.

Data collected. Germination counts were made at weekly intervals in the greenhouses and

germinator. Emergence of the seedlings through the peat-lite mix was used as the basis for

germination counts in the greenhouses. Although eastern gamagrass is not included in the Rules

for Testing Seeds of the Association of Official Seed Analysts (AOSA), seedling evaluation in the

germinator followed the same general criteria used for grasses, viz., development of a primary

root and a leaf extending more than half the length of the coleoptile. Abnormal seedlings, such

as those with no root development or leaf extending half or less the length of the coleoptile, were

not included in the percentage germination.

Tetrazolium chloride assay. To determine whether or not reductions in seed germination were

caused by dormancy or a decline in viability, tetrazolium chloride (TZ) tests were run after 28

days. This assay was carried out using a 0.1% solution of 2,3,5-triphenyl tetrazolium chloride

prepared in a sodium phosphate buffer solution (Grabe 1970; Moore 1985). In the presence of

living cells, the colorless TZ solution becomes reduced to a reddish, water insoluble compound.

Imbibed, ungerminated seeds are bisected longitudinally through the embryonic axis. The cut

surfaces of each half are placed face-down on filter paper that is saturated with a 0.1% solution of

TZ in a covered container. This is placed in an oven at 35o

C for approximately 2 hours or until

staining is complete. Evaluation of the seeds is done after staining.

Seeds are considered to be viable if essential structures of the embryonic axis are stained and

appear otherwise sound. In eastern gamagrass, as in other grasses, the endosperm does not

stain. Ungerminated seeds that are determined to be viable by the TZ test are considered

dormant. TZ testing was done on seeds remaining ungerminated at the end of the germination

test for DATE 5 (July 1999) and DATE 7 (September 1999). TZ testing was also done on freshly

imbibed seeds at the beginning of DATE 5. Two replicates of 100 seeds each were allowed to

imbibe overnight on germination paper moistened with water.

Statistical analysis and graphs. Statistical analysis of the data collected in the ARS and NRCS

greenhouses and in the AMS laboratory were carried out using PROC MIXED (SAS Institute).

Graphs of germination results were drawn using non-parametric loess (local regression) plots

using Axum (Mathsoft Inc.) statistical graphics software. The fit parameter λ was 1, i.e., locally

linear, and the panel size parameter α was 0.50.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

185

Results

ARS and NRCS Greenhouses. The percentage germination on day 28 was analyzed as a 3-

factor general linear mixed model using PROC MIXED with DATE, 1-7, and YEAR, 1998 and 1999,

as the fixed factors and location (LOC) the random factor. The assumptions of the general mixed

model were tested. To correct the variance heterogeneity, treatments were grouped into similar

variance groups for the analysis.

The analysis of variance results showed the YEAR × DATE interaction to be significant (F=2.31,

p=0.0511) and the main effect DATE highly significant (F=21.56, p≤0.0001) while YEAR was not

significant (F=1.96, p=0.1675).

Means were compared using pair-wise contrasts (Table 1). Overall, there was no significant

difference in average percentage germination in the greenhouses between the two seed lots

(42% for 1998 and 40% for 1999); only at DATE 4 (July 7) was there a significant difference

between the two years. The most striking differences in percentage germination were between

DATE 1 (April 14) and DATE 2 (May 12); this was true for both 1998 and 1999 seed lots.

Significant differences were also observed between DATE 3 (June 9) and DATE 4 (July 7) for the

1999 seed lot.

The comparative germination responses of the two seed lots in the greenhouses showed a

similar pattern (Fig. 1), with high initial percentage germination and then a gradual smooth

decline.

Table 1. Means and means comparisons for the greenhouse study

DATE

 YEAR 1 2 345 6 7

YEAR

Avg.

 1998 59.33a1

x

 2 40.83a y 45.00a xy 36.33a y 34.67a y 37.50a y 40.33a y 42.00

 1999 70.83a x 34.83a yz 43.50a y 26.17b z 33.67a yz 36.50a yz 33.33a yz 39.83

 DATE Avg 65.08 37.83 44.25 31.25 34.17 37.00 36.83

1

 Column (Year within Date) means with different a,b letters are different at p ≤ 0.007 significance

level. (Experiment-wise error 0.05)

2

 Row (Date within Year) means with different x,y,z letters are different at p ≤ 0.002 significance

level. (Experiment-wise error 0.05)

AMS Laboratory. The number of seeds germinated by day 28 was analyzed as a two-factor

general linear model using PROC MIXED with DATE and YEAR as the factors. The assumptions of

the general linear model were met. Analysis of variance results showed that both main effects

were statistically, significant YEAR (F=9.27, p=0.0040) and DATE (F=3.31, p=0.0462), while the

YEAR×DATE interaction was not significant (F=0.40, p=0.6737).

The means were compared using pair-wise contrasts where the p-value was adjusted for the

number of comparisons so that the overall p-value was 0.05. Table 2 shows that overall, the

1999 seed lot had significantly higher average percentage germination than the 1998 seed lot.

There were also significant differences in average percentage germination between DATE 2 and

DATE 7.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

186

Table 2. Means and means comparisons for the AMS germinator study

DATE

YEAR 2 5 7YEAR AVG

1998 67.25 65.75 63.50 65.50b1

1999 75.50 71.50 67.00 71.08a

DATE Avg 71.00x 2 68.62xy 65.25y

1

 YEAR means with different letters are different at p=0.040 significance

level.

2

 DATE means with different letters are different at p≤0.017 significance

level, (overall p=0.05).

1234567

Date

20

40

60

80

Germination (%)

1998

1999

Figure 1. Loess (local regression) curves and germination values for 1998 and 1999 lots of

eastern gamagrass in the greenhouse after 28 days at seven planting dates: March 17 (Date 1) to

September 2, 1999 (Date 7). Data for ARS and NRCS greenhouses combined.

Investigation into the trend of seed germination over storage time showed that there were

differences in the shapes of the curves (Fig. 2, Table 3). The 1998 seed lot showed a flat line

indicating no difference in germination at the 3 dates, while the 1999 seed lot (Fig. 2, Table 3)

and combined 1998 and 1999 seed lots (Table 3) showed decreasing straight lines which

indicated that germination decreased over time.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

187

Table 3. Trend analysis – p-values for AMS germinator responses

YEAR Linear Quadratic

 98 0.2537 0.7878

 99 0.0210 (-) 0.6157

 98 & 99 0.0159 (-) 0.5858

234567

Date

50

60

70

80

Germination (%)

1998

1999

Figure 2. Loess (local regression) curves and germination values for 1998 and 1999 lots of

eastern gamagrass in the germinator after 28 days. Seed planted at three dates: April 14 (DATE

2); July 8 (DATE 5); and September 2, 1999 (DATE 7).

The germinated and ungerminated (dormant + dead) seeds by day 28 were analyzed as twofactor general linear models using PROC MIXED with DATE and YEAR as the factors. The

assumptions of the general linear model were met. The analysis of variance results indicate that

only YEAR was statistically significant for the germinated (F=4.16, p=0.0509) and ungerminated

(F=5.96, p=0.0212) seed.

Table 4 shows that the 1998 seed lot had a significantly greater percentage of ungerminated

seed than the 1999 seed lot.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

188

Table 4. Means and means comparisons for AMS germinator study

Germinated Ungerminated

YEAR 5 7YEAR AVG 5 7YEAR AVG

 1998 65.75 63.50 64.62b1 32.25 36.00 34.12a 2

 1999 71.50 67.00 69.25a 27.00 31.25 29.12b

DATE AVG 68.62 65.25 29.62 33.62

1

 Year means with different letters are different at p=0.05 significance level.

2

 Year means with different letters are different at p=0.05 significance level.

Since there were just two dates, only a linear trend could be tested over storage time. The results

showed flat lines indicating that there were no differences for the seed lots (storage years) at the

two dates (Table 5).

Table 5. Trend analysis – p-values for AMS germinator study

 YEAR Germinated Ungerminated

 98 0.4887 0.2059

 99 0.1715 0.1533

 98 & 99 0.1478 0.0608

The number of dormant or dead seeds at day 28 was analyzed as a three-factor general linear

model using PROC MIXED with DATE, YEAR, and CONDITION (dead or dormant) as the factors. To

correct variance heterogeneity, the variance grouping technique was used. The analysis of

variance results showed statistical significance only for the effects YEAR (F=4.38, p=0.0422),

COND (F=130.15, p≤0.0001) and YEAR X COND interaction (F=31.94, p≤0.0001).

The means (Table 6) were compared using pair-wise contrasts where the p-value was adjusted

for the number of comparisons so that the overall p-value is 0.05. The 1998 seed lot had a

significantly lower percentage of dormant seed and a higher percentage of dead seed than the

1999 seed lot.

Table 6. Means (%) and means comparisons of 1998 and 1999 Seeds that were dormant or

dead in AMS germinator study

Condition

YEAR DORMANT DEAD YEAR AVG.

1998 6.87b1 y

 2 27.25a x 17.06

1999 11.12a y 18.00b x 14.56

9.00 22.62

1

 Column (Condition within Year) means with

different a,b letters are different at p ≤ 0.0050

significance level.

2

 Row (Year within Condition) means with different

x,y letters are different at p ≤ 0.0050 significance

level.

A TZ test conducted in an AMS laboratory germinator at the end of 28 days indicated that the

mean percentage of dead seeds was higher at Test 7 than at Test 5 for both 1998 and 1999 but

that (Table 7).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

189

Table 7. Means (%) of dead and dormant seeds in Tests 5 and 7 in AMS germinator study

Condition

DORMANT DEAD

 DATE 57 57

 1998 7.00 6.75 25.25 29.25 YEAR 1999 11.00 11.25 16.00 20.00

Discussion

The present studies provide the first evidence for time-course differences in germination

responses of Germtec IITM treated eastern gamagrass seeds over a six-month period. The

gradual decline in percentage germination of both 1998 and 1999 seed lots of Germtec IITM

treated seed observed at 28 days in both ARS and NRCS greenhouses from 59% and 71%,

respectively, on April 14, 1999 to 41% and 35%, respectively, on May 12, 1999 is consistent with

what we observed the previous year and suggests that the stimulatory effects of this seed-priming

treatment are relatively short lasting. However, the fact that the 1998 seed lot showed a

resumption in germinability, as evidenced by the high initial germination count in April 1999 after

dropping to 35-40% the previous summer, suggests that either the effects of the initial seed

priming treatment might not have been lost entirely or that a secondary dormancy induced during

late spring was broken during subsequent cold storage. This may involve some combination of

morphological and physiological changes, whose nature remains to be determined.

The variation in percentage germination of eastern gamagrass in our greenhouses from April to

September 1999 during the current study is consistent with findings for eastern gamagrass

reported by Row (1998b) and his associates over a twenty-five year period in a seed storage

study conducted in Kansas at the NRCS/Plant Material Center (Fig. 3). Their data show that the

germination percentage of a single seed lot of eastern gamagrass kept in dry storage in Kansas

under controlled conditions and tested at 14 or 21 days varied from 24 to 58%. While some of

this variation is undoubtedly due to differences in environmental conditions from year to year,

Row (personal communication) has suggested that much of the variation could be accounted for

by the presence or absence of a caryopsis and the fact that a random population of seed is

generally taken from the container.

Two factors that might explain the large difference in percentage of seed germination between

the germinator and the greenhouses are differences in temperature and relative humidity. The

germinator had an alternating day-night temperature as required (AOSA 1999) for nearly all

cultivated grasses. On the other hand, in the greenhouse the soil temperature remained

relatively constant since the propagating mat was kept on continuously. In addition, the

atmosphere in the germinator was saturated.

Based on TZ tests, loss in viability was primarily responsible for the decline in germination

percentage with time. The fact that the 1998 seed lot had a higher percentage of dead seed by

late summer (DATEs 5 and 7) than did the 1999 seed lot may be attributed to the increased age of

the seed. Results of the total percentage germination plus dormant seed (83%) obtained at Date

5 for the 1999 lot seed compared favorably to the percentage of viability on the seed label (85%).

At DATE 7 the 78% observed is within the allowable tolerance of the Federal Seed Act Regulation

(2000).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

190

0 5 10 15 20 25

Year

0

10

20

30

40

50

60

Controlled

Germination (%)

Uncontrolled

Figure 3. Twenty-five year germination record of a single lot of eastern gamagrass kept in dry

storage at the NRCS Plant Materials Center, Manhattan, Kansas under controlled and

uncontrolled conditions. Germination tests run after 14 or 21 days. Data from John Row (1998b).

However, the term hard seed on the label provided by the supplier, while suitable for describing

certain leguminous seeds, is not really appropriate for characterizing dormancy of eastern

gamagrass seed. Based on our results, we recommend that the seed label reflect both the total

percent germination as well as the total percent dormant seed. By providing such information on

the seed label, seed companies can provide the grower with valuable information in making

decisions as to adjustments that may be necessary in planting density.

At present, there is no standard AOSA seed testing procedure to determine germination of

eastern gamagrass (Dewald 1993), and Federal Seed Act Regulations do not presently apply.

Because of seed dormancy characteristics of currently available germplasm and variations in

seed testing protocols, laboratory tests may be misleading (Dewald 1993). Dewald (personal

communication) has indicated that he sent seed samples of identical lots of eastern gamagrass

for testing to several seed testing laboratories and obtained wide differences in germination

results.

Seed dormancy in eastern gamagrass and in many other warm season grasses has been

attributed to various morphological and physiological factors. These include structures

surrounding the embryo, the physiological state of the embryo itself or a combination of these

factors (Anderson 1985, 1990; Coukos 1944; Crocker 1916; Knapp 2000; Simpson 1990). The

seed of eastern gamagrass is encased in a tough “capsule” referred to as a cupulate fruitcase

(Galinat 1956) or cupule (Row 1998a, Knapp, personal communication). There is increasing

evidence that the cupule may provide a significant morphological barrier to germination in eastern

gamagrass since its removal (including lemma and palea) and scarification of the caryopsis have

been found to be effective in overcoming dormancy (Knapp, personal communication). Anderson

(1985) showed that germination could be increased from 5% in the control (with intact cupule) to

40% by removing the cupule but failed to explain the basis for the residual dormancy.

Our results indicate that the germination behavior of eastern gamagrass is highly complex and

may involve interplay of many different factors, some of which may still need to be described.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

191

There is no consistent duration used for the pre-chill period or for the germination test. It would be

helpful if standardized germination procedures were published for this species. This would

greatly facilitate making intercomparisons of data.

Based on reports in the literature (Dewald 1993), we conclude that Germtec IITM treatment would

be equivalent to that provided by pre-chilling. At BARC, Germtec IITM treated seed received in

March 1999 was planted (with irrigation) in May 1999 at an increased density to compensate for

the reduction in germination percentage observed in the greenhouse. This resulted in good stand

establishment (unpublished data). Based on our results, we would expect that a 1-2 month delay

in planting might result in a lower percentage of seedlings established. Yet, this number would

still greatly exceed the numbers of seedlings likely to emerge using untreated seeds. Reports

from cooperators in several Maryland counties support this contention. We welcome feedback

from other investigators who have used seeds given this priming treatment.

Acknowledgments

Grateful acknowledgments are extended to John Englert for his encouragement and support of

this study; John Row for sharing unpublished data from his Masters thesis at Kansas State

University and in providing unpublished data for the illustration used in Figure 3; Chet Dewald for

his insightful thoughts on dormancy and for sharing his storehouse of knowledge on the culture of

eastern gamagrass; Allen Knapp for providing drafts of two manuscripts on dormancy in eastern

gamagrass and other warm season grasses and for helpful discussions in trying to interpret the

results; Louis Rose for his careful monitoring of environmental conditions in the greenhouse;

Roman Mirecki and Randy Rowland, for their helpful suggestions in solving various computer

problems; David Bitzel and Leigh Wiltison for their expert assistance in conducting the tetrazolium

chloride assays; and Debbie Stevens and Dean Stevens, Gamagrass Seed Co., for providing

unpublished data on germination tests conducted. Partial funding provided by USDA Competitive

Research Grant awarded to Donald Krizek, Principal Investigator.

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pp. 195-204. In: D.E. Walling and J.L. Probst (eds.), Human Impact on Erosion and

Sedimentation, International Association of Hydrological Sciences Publication No. 245.

Row, J.M. 1998a. Establishment of eastern gamagrass with pre-germination seed treatments.

M.S. Thesis, Kansas State Univ., Manhattan, KS. 47 pp.

Row, J.M. 1998b. Unpublished data. Study No. 20A107T - Seed Storage Study. USDA/NRCS

Plant Materials Center, Manhattan, Kansas.

SAS Institute Inc., SAS/STAT7 Software: Changes and Enhancements through Release 6.12,

Cary, NC: SAS Institute Inc. 1997. p 1167.

Simpson, G.M. 1990. Seed dormancy in grasses. Cambridge Univ. Press, Cambridge, UK. 297

pp.

Tian, X., A.D. Knapp, K.J. Moore, E.C. Brummer and R.L. Hintz. 1997. Seed dormancy and

germination of eastern gamagrass. Iowa Seed Sci. 17(2):5-6.

Tischler, C.R., B.A. Young, and M.A. Sanderson. 1994. Techniques for reducing seed dormancy

in switchgrass. Seed Sci. and Technol. 22(1):19-26.

Toole, E.H., S.B. Hendricks, H.A. Borthwick and V.K. Toole. 1956. Physiology of seed

germination. Ann. Rev. Plant Physiol. 7:299-324.

Wright, L.S., C.M. Taliaferro, and F.P. Horn. 1983. Variability of morphological and agronomic

traits in eastern gamagrass accessions. Crop Sci. 23(1):135-138.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

194

Cool Season Natives Common To Southeastern Riparian Areas

Alison Krohn1

The basis of this paper is observation rather than scientific trial and evaluation. As a member of

the Southeast Regional Engineering Team for USDA Natural Resources Conservation Service

(NRCS), I worked with engineers and conservationists in several southern states on streambank

stabilization projects. Wherever feasible soil bioengineering techniques were used and native

plants were recommended for the vegetative component of these practices. The desire of the

engineering team was to use plants native to the watershed for stabilization, preferably from the

same stream. Existing stable riparian areas were explored especially those proximate to the site.

An inventory of trees, shrubs and groundcover species was recorded for each site. This paper

will focus on the cool season native grasses that were most common, tolerant of the widest range

of conditions, or exhibited desirable aesthetic qualities.

The need for aesthetically pleasing plants was identified by conservationists working in urban

areas where native ecosystems are at greatest risk. Aesthetics is an important issue for

landowners who prefer a “clean” stream bank and routinely mow to the edge of the bank. Areas

that are mowed cannot regenerate woody plants and many native grasses and forbs will not

survive. Management plays a critical role in the stability and condition of riparian areas. If we

can identify and plant aesthetically pleasing species then perhaps the mowing can be pushed

back a safe distance from the water’s edge for both landowners and riparian systems.

Observations

Cool season native grasses are common groundcover components of riparian systems in the

southeastern states. The groundcover component on stream banks and floodplains provides

surface scour resistance. This groundcover component also increases the friction coefficient

thereby decreasing the erosion potential of floodwaters. Typically 50% of the groundcover will be

composed of grasses, the remainder being forbs. Some of the most common species observed

at sites in South Carolina, Tennessee and Kentucky were Virginia wildrye [Elymus virginicus L.],

switchcane or rivercane [Arundinaria gigantea (Walter) Muhl.], and river oats [Chasmanthium

latifolium (Michx.) H.O. Yates]. Virginia wildrye appeared to be the most tolerant of disturbance

and a wide range of solar exposure from full sun to full shade. It was observed on over half of the

sites visited in the three states. Switchcane was present on 48% of the sites and is also tolerant

of sun and shade. It is not available commercially and is established by transplanting. River oats

was observed only 5% of the time but it has great aesthetic appeal. Limited seed sources are

available commercially and several nurseries including Burpee Seed Company offer this grass in

potted form. The chart below shows the number of sites where these grasses were found

between 1998-99. Forty-five sites were visited in total.

In vegetative stabilization projects or soil bioengineering the role of grasses is critical to the initial

stability of the site. Until the trees have survived three years, they provide little protection. In fact

we have had almost as much success with natural succession as with seedlings. Since grasses

provide the initial protection on a stabilization project it is important to use reliable species.

Additional concerns include the risk of introducing invasive species, such as overly aggressive

grasses that will out-compete woody vegetation, or fail as the tree canopy matures. The value of

cool season natives such as Virginia wildrye is they tolerate both sun and shade. As the canopy

matures this grass will thin out, yet persist. The same is true of switchcane. It may be more

aggressive than wildrye, but is much more difficult to establish and does not seem to expand

aggressively for several years after transplanting.

 

1

 Department of Architecture and Landscape Architecture, North Dakota State University, P.O.

Box 5285, Fargo, ND 58105-5285
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

195

Virginia wildrye planted on a stream Switchcane growing on a stream in

bank in South Carolina South Carolina

Experiences

Having established the value of native plants that are adapted to local conditions and local flora

and utilized by local fauna, we attempted to use them in the projects described below.

Claredon Estates, Anderson, SC

Local NRCS conservationists were asked by a group of residents living in the Claredon Estates

subdivision to address erosion problems in a stream that ran along one side of the development.

The sites were difficult to deal with because they were literally in people’s back yards and had

limited access. The typical riprap solution was neither practical nor cost effective. Aesthetics

was a concern for the residents. Like many streams in the piedmont, this one was entrenched

and showed some evidence of downcutting in the upper reaches, but the majority of its length

was lined with mature trees: the resident’s backyard landscapes. Under the emergency

watershed program a series of riprap grade control structures were installed and coconut fiber

rolls were used for toe protection where needed. The remainder of the project was the

installation of vegetation. Switchcane was transplanted along with local rushes [Juncus effusus

L.]. Where the banks were disturbed, Virginia wildrye was seeded at a rate of 20 lbs per acre.

This took place in February. The following July the sites were inspected and the wildrye had

germinated and showed vigorous growth. Not all of the switchcane had survived but it

outperformed the other local material. The cool season natives performed well in heavy shade,

which had been a major challenge of this project.

0

10

20

30

40

Elymus virginicus Arundinaria gigantea Chasmanthium

latifolium

none found

Number of sites species found
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

196

Portland Channel

Under a project authorized during the 1960’s, NRCS in Tennessee had built a floodway for a town

on the Kentucky border. An extension was built in 1997 and the site was required by state

regulations to be seeded with native species. A mixture of switchgrass and Virginia wildrye was

used.

12 lbs switchgrass

20 lbs Virginia wildrye

1⁄2 bushel rye grain

2 tons lime

30 lbs 0-20-20

1.5 tons straw mulch

The channel was seeded in August and the grasses performed better than expected. In the

second growing season both species had formed seed heads and exhibited good cover except

on some south facing slopes that were extremely dry.

Poor coverage on upper slope Successful seeding at Portland

This combination of switchgrass and wildrye has been recommended for use on several stream

stabilization sites throughout Tennessee. Our desire was to develop a mix that could be seeded

at any time of year. Using both warm and cool season species means at least one will be seeded

at an inopportune time but there is always the chance of later germination if the seed has not

been washed away by floodwaters. The Tennessee Wildlife Resources Agency (TWRA) has

donated seed to be used on sites throughout the state, especially those not funded under any

other programs. The success of native grasses seeded without inspection or local guidance has

been poor to date for reasons discussed below.

Challenges

Conservation concerns that fall outside of funded programs are difficult to control and assess.

Typically, NRCS personnel will make recommendations or develop plans for the landowner to

implement. How these recommendations are implemented depends on the landowner’s

resources, including time, access to materials and recommendations from other sources. What

usually happens is the cheapest seed from the local Co-op is planted. Warm season native seeds

are more common than they were ten years ago, but cool season natives are still a specialty item.

Many landowners have never heard of Virginia wildrye even though it may be underfoot. They

will prefer to use fescue, which they know how to seed. Familiarity supercedes recommendations

when the landowner is financing and installing a project. The TWRA program has overcome

some of the resistance but lack of experience in the field has hampered success with warm

season grasses such as the switchgrass. Natives do not require the same fertilization as
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

197

introduced species, and have narrower seeding dates, although Virginia wildrye seems to be very

similar to fescue in its range. Cost and availability are additional hurdles in the wider use of cool

season natives. Switchcane must be transplanted since it is not available commercially, and to

my knowledge, it does not propagate by seed.

Opportunities

There is a need for cool season native grasses in restoration and stabilization projects. The

species described above take flooding very well, are adapted to sun and shade, and will not

create a threat to local ecosystems. If we wish to protect our streams and riparian systems we

need to address the landscape industry and aesthetic expectations of the public. The image of a

stream coursing through a mowed landscape must change to one of swaying seed heads and

trees of diverse size and age. Both Virginia wildrye and river oats have interesting seed heads

that could be enhanced through selection and breeding. Switchgrass has made inroads into the

landscape industry as an ornamental and the same is possible with the other native grasses.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

198

Plant Conservation Alliance

Olivia Kwong1

Defining the Problem

As of the end of September 1999, the Fish and Wildlife Service’s (FWS) federal list of threatened

and endangered plants and animals contained 716 plants and 481 animals, a ratio of 3 to 2. The

problem becomes clear when you look at a sample federal agency’s threatened and endangered

species expenditures. Year after year, of the millions in total funding spent on endangered

species, most is spent on animal species and a mere fraction on plant species which make up

over 60% of the list.

The major land managing federal government agencies own roughly 29% of the United States,

651 million acres. To put this information in perspective for you, the comparably sized country

can be found for each agency’s landholdings: Department of Defense (DOD) and Austria;

National Park Service (NPS) and Norway; FWS and Japan; USDA Forest Service and Turkey;

Bureau of Land Management (BLM) and Egypt. Each year these agencies deal with a variety of

issues such as restoration, wildfires, and invasive exotic species. The BLM alone lost 2.5 million

acres to wildfires in the Great Basin area during the summer of 1999. However, personnel

numbers from 1999 show that in NPS, FWS, U.S. Geological Survey USGS), and BLM (BLM data

approximated from 1997) the ratio of botanists or plant specialists (20-45) to the total number of

biologists (3,444 to 390) ranges from less than 1% to 11%.

Creating and Providing Solutions

In 1994, 80 participants representing 34 agencies and organizations met during a workshop in

Phoenix, Arizona to discuss the problems plaguing native plant conservation on federal and

private lands. The meeting resulted in the writing of a Native Plant Conservation Strategy and the

creation of the Native Plant Conservation Alliance, now known as the Plant Conservation Alliance

(PCA).

PCA is a consortium of ten federal government Member agencies and over 150 non-federal

Cooperators representing various disciplines within the conservation field. Currently, there are

ten federal agencies officially participating in the PCA as the Federal Committee. The agencies

which have signed the Memorandum of Understanding are the BLM, DOD, Federal Highway

Administration, NP, Office of Surface Mining Reclamation and Enforcement, USDA Agricultural

Research Service, USDA Forest Service, USDA Natural Resources Conservation Service, FWS,

and USGS. The non-federal Cooperators include a range of professional societies, trade

associations, research organizations, universities, state agencies, museums, growers, non-profit

organizations, gardens and arboreta, native plant societies, garden clubs, and Native American

tribal councils. These partners share PCA’s mission: "To protect native plants by ensuring that

native plant populations and their communities are maintained, enhanced, and restored."

PCA Members and Cooperators work collectively to solve the problems of native plant extinction

and native habitat restoration, ensuring the preservation of our ecosystem. Strategically, the PCA

aims to help establish common priorities and direction in plant conservation activities among

cooperators; support collaborative efforts, including training programs; coordinate public

education and outreach efforts; and develop networking tools for communication and

coordination. The PCA provides the organization and structure to implement the overall mission

through those specific goals.

 

1

 Webmaster and Information Manager, Plant Conservation Alliance, 1849 C St. NW, LSB-204,

Washington, DC 20240, (202) 452-0392, olivia_kwong@blm.gov.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

199

When used as a tool in restoration, natives should be seen as a solution to many of the problems

facing agencies on their lands. In order for this to happen federal plant conservation resources

must be pooled at the national level to provide a focused, strategic approach to plant

conservation at the local level on public and private lands, eliminating duplication of effort and

increasing the effectiveness of these programs.

Recognizing the diverse participation and methods needed for their work, PCA invites federal,

non-profit, state, industry and other interested parties to participate in technical working groups

covering the following areas: Alien Plant, Data & Information Sharing, Medicinal Plant, Pollinator,

Public Outreach, and Restoration Working Groups.

Each year, PCA awards thousands of dollars for on-the-ground conservation and restoration

projects through a matching funds grant program administered by the National Fish and Wildlife

Foundation. Since PCA’s inception in 1994, grants have been awarded for more than 100

projects totaling over $2,000,000 in federal funds and matching non-federal contributions.

However, native plant conservation does not consist of funding alone; PCA, as a public-private

partnership, also serves as a forum for the exchange of ideas, expertise and information between

organizations engaged in habitat restoration and preservation. These exchanges take place in

various forms of public outreach, including e-mail lists, postal mailings, a website, a bi-monthly

newsletter, and meetings.

The PCA website contains:

 Alien Plant Working Group section with a comprehensive list of troublesome

invasive plants of natural areas, separate lists for aquatics, herbs, vines,

shrubs, and trees, fact sheets produced in a consistent format with a nationwide perspective, and links to exotic pest plant councils, national parks, other

web sites, persons, and organizations working on the issue.

 Restoration Working Group section (in development)

 Medicinal Plant Working Group section (in development)

 Information on the NFWF Grant Program

 Celebrating Wildflowers Coloring Book and the On-Line Events Directory for

North America

 PCA Cooperator list with links to member pages

 Planting Foundations newsletter and announcements for native plant

conferences and symposia

 On-line copies of the current meeting agenda, national strategy, Wild Wealth

brochure, and other useful information

Please see our website for more information about the Plant Conservation Alliance at

http://www.nps.gov/plants/
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

200

Army Training Lands - The Native Perspective

David G. Lorenz1

The U.S. Army’s twelve million acres of training lands are some of the most unique and diverse

land areas in the nation. These lands often contain pristine vegetation including rare and

threatened plants, and are in many cases some of the last remaining undisturbed habitats for

vegetative and wildlife species. On the other hand, the active portions of these lands are some of

the most intensively used in the nation and therefore are subject to severe soil erosion and the

loss of native vegetation and wildlife habitat.

Native plants thrive on the live fire ranges and buffer areas of training lands because there is

relatively little disturbance on these areas. However, on the heavily used areas of active training

the opposite occurs. Continuous or intermittent wheeled, track or foot traffic on roads and trails

combined with rigorous training on open ground, bivouac and convergence areas tend to

eliminate most of or all of the existing vegetation. The recent closing of some training units has

concentrated activities on the remaining units, intensifying training, and further stressing

remaining vegetation.

Native plants, particularly grasses, have a vital role in stabilizing, maintaining and reclaiming

Army training lands. The difficulty arises in determining the situations in which natives can be reestablished for permanent vegetative cover on active training lands and be able to tolerate the

amount of scheduled training for the area.

I am a Natural Resources Conservation Service (NRCS) liaison to the US Army Environmental

Center (AEC) headquartered at Aberdeen Proving Ground, MD. The Army Environmental

Center’s primary mission is to help installations keep their training lands open and available for

training. This is an all-encompassing role including cleanup of chemical spills, designing oil and

water separation devices for recycling, cleanup of contaminated ground water, cleanup of UXO

(unexploded ordnance), and stabilizing the soil on training lands. Soil stabilization is the key to

ensuring that compliance actions do not shut down training activities. This mission is getting

harder to do as the recent closing of a number of training areas has concentrated the same

amount of training on existing areas. There are three NRCS liaisons located at the Center, along

with liaisons from the Forest Service, Fish and Wildlife Service, Geological Survey, Bureau of

Land Management and the Advisory Council on Historic Places. Army Civilian Biologists,

Chemists, Engineers and contractors hold most of the USAEC positions. It all makes for an

interesting and diverse work group not always agreeing on the same solutions.

My role at the AEC is to assist in reclaiming training grounds either lost or threatened to be lost to

training because of soil erosion or soil and water contamination and to prevent this from

happening on the remaining training sites. I have been to problem areas on 15 installations in an

effort to help them control soil erosion and re-vegetate training lands. Some of these areas have

had sparse or no vegetation growing on them for many years. Many of these sites have no

topsoil; some are or have been contaminated with metals, fuel spills or chemical spills.

The Army mission is to “train soldiers” under as many diverse landscapes as possible. This is

where the NATIVE PERSPECTIVE on Army training lands comes into focus. In its effort to revegetate these lands, the Army will use whatever vegetation that can do the job. Natives are

selected when available, then whatever else that will meet the mission. The problem is that there

 

1 NRCS Plant Materials Specialist Liaison to the US Army Environmental Center, Aberdeen

Proving Ground, MD
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

201

are not many natives, especially cool season grasses, that are adapted to solve the unique

vegetative needs presented by the Army.

Some of the situations that the Army is up against include:

1) 70 ton tanks tear up a lot of ground that in many cases does not get a chance to recover

because of the continuous training, poor soil conditions or lack of reseeding efforts and /or

proper species to reseed with.

2) Small arms firing ranges are in constant use and because of the safety regulations (steep

berms-short mowed grass) tend to be bare and to erode. Not only is the loss of soil important

but so is the wash of metals and other contaminants that may go with it.

3) Roads, trails and footpaths are continuous sources of soil erosion.

4) Many training areas can never be rested long enough to recover, haven’t healed and are now

critical area sites in dire need of reclamation.

5) Invasive, many times exotic, plants are often more situated to this hostile environment and

tend to become established in place of natives and continue to spread as the training

intensifies or is prolonged on these areas.

The following two projects involve developing new and unique methods of reclamation and

maintenance procedures to control erosion and establish vegetation on damaged training lands.

Project Berm Stabilization - Fort Jackson SC:

The objective of the study is to diminish the effects of bullet pockets and the resulting soil erosion

on small arms firing ranges. Bullet pockets are a necessary evil on small arms firing ranges. The

resulting erosion caused by the bullet pockets is a continuos problem. Attempts to contain the

pockets have led to the construction of bullet traps made from shock absorbing concrete

(SACON). There is a complete absence of vegetation on the berm even though the area was

seeded during March, which is a good time of year for seeding in South Carolina. Failure to

promptly re-seed, re-seed correctly and failure to maintain new seedings are just a few of the

reasons there is sparse vegetation on most berms on small arms training ranges. Change of

mindset and scheduled maintenance will help in the battle to maintain vegetation on berms and

training floors. However, it will take native plant selection and breeding to produce “natives” that

can survive the abuse of small arms training ranges.

Project Vegetative Wear Tolerance Study - Fort Leonard Wood, MO.

The objective of the study is to determine what species of vegetation is the most tolerant to five

common wear situations on Fort Leonard Wood. The three-year study was established during the

spring and summer of 1998. The NRCS Elsberry, MO, Plant Materials Center is conducting the

study.

The study is in progress. The following are the results of the study through October 1999.

Site #1. Barracks Lawn

Species being evaluated:

Rebel Jr. tall fescue Meyer zoysia grass

Leprechaun tall fescue Marage bermudagrass

Finelawn tall fescue Chieftain tall fescue

Tufcote bermudagrass Jaguar tall fescue

Mo-Buff buffalograss Adobe tall fescue

Divine perennial rye KY-31 tall fescue

Observation 10/99: Tufcote looks best. Doubtful if Zoysia can take traffic. Buffalograss is slow in

getting started, but may be a good survivor.
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202

Site #2. TA-244 Upland vehicle traffic site

Species being evaluated:

Rumsey Indiangrass Lespedeza Daurica Schimadea

VA-70 Shrub lespedeza KY-31 tall fescue

Indian switchgrass Cimarron little bluestem

Observation 10/99: Ky-31 tall fescue and the Cimarron little bluestem look the best.

Site #3 Disturbed Bottomland

Species being evaluated:

Leprechaun tall fescue Rumsey Indiangrass

Rebel Jr. tall fescue Lespedeza Daurica Schimadea

Chieftain tall fescue Loreed Reed Canarygrass

Ky-31 tall fescue Sodar Streambank Wheatgrass

Indian switchgrass Bottlebrush Squirrel tail

Observation 10/99: This site has been abandon due to a tremendous influx of weeds.

Site #4 Bivouac Area

Species being evaluated:

Shademaster II red fescue Chieftain tall fescue

Flyer red fescue Finelawn 5GL tall fescue

Covar sheep fescue Finelawn petite tall fescue

SR-3100 hard fescue Divine perennial rye

Unique KY bluegrass

Observation 10/99: No traffic has been employed on the site. SR-3100 Hard Fescue looks the

best followed by Flyer red fescue and Unique KY bluegrass. Plant in the spring to avoid a

smothering effect from leaf drop. Virginia wildrye was not selected for evaluation because it grows

too tall for this type of training.

Site #5 Active Small Arms Range

Species being evaluated:

Bottlebrush squirrel tail Lespedeza daurica schimadea

Guymon bermudagrass Top gun buffalograss

TifBlair centipedegrass

Observation 10/99: This is an extremely tough site. Top gun buffalograss is the choice so far.

TifBlair centipedegrass looked excellent the establishment year but deteriorated during the

second growing season.

RECOMMENDED ACTIONS

6) Rest and rotate training lands as much as possible

7) Plant native species when available to reclaim training lands

8) Follow a maintenance plan to establish and maintain training areas

CONCLUSION

There are not many native species especially cool season grasses, which can compete with

introduced cool season species, for use on Army training lands.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

203

Remembering the Army mission “To Train Solders” it is a must to keep Army training lands open

for training. The Army will use whatever species are available do the job, selecting natives first

when available and applicable, then whatever will meet the mission. The problem is, there are

not enough native species available, and in some cases no native species available, to

adequately support the mission.

I believe that through proper selection and breeding, native species can become competitive with

introduced species on tough sites, not only on Army training lands, but anywhere America needs

them. This is a challenge to our grass breeders and others who work with native grasses to

concentrate more work in this area, as our soldiers and our lands depend on it.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

204

Developing Integrated Weed Management Strategies to Restore Great

Plains Grasslands

Robert A. Masters, Daniel D. Beran, Fernando

Rivas-Pantoja, and Roch E. Gaussoin1

The productivity of Great Plains grasslands has been substantially reduced by past management

that enabled the establishment of invasive exotic weeds and displacement of native species.

Many grasslands are comprised of degraded plant communities with reduced native species

diversity and are producing at less than 50% of their potential. According to the 1992 National

Resources Inventory conducted by the USDA-Natural Resources Conservation Service, there are

over 70 million acres of degraded grassland in the Northern Great Plains in serious need of weed

management, site stabilization, and reclamation.

The focus of grassland management should be to improve degraded grassland communities in a

manner that makes them less vulnerable to invasion by exotic weeds and to spread of

undesirable native species. In many instances grasslands have deteriorated to the point that

desirable species are either not present or in such low abundance that grassland recovery will be

unacceptably slow without direct intervention. A generalized model describes grassland

degradation and improvement processes (Figure 1). Site-specific management systems

comprised of multiple, complementary technologies or tools applied in appropriate sequences are

developed. Such management systems can improve grassland quality and to optimize

improvement of degraded grassland need to decrease negative impacts of undesirable exotic and

native species.

Figure 1. Proposed improvement model for Great Plains grasslands. Degradation leads to

steady state conditions of low productivity. Reliance on a single technology results in slow

grassland recovery rate. Implementation of integrated weed management strategies accelerates

development of high quality grasslands.

 

1

USDA-ARS and Departments of Agronomy and Horticulture, University of Nebraska,

Lincoln, Nebraska 68583

Overgrazing

Fire exclusion

Conversion

 to cropland

Introduction of 

 exotic weeds

Steady state

Single technology

Biological control

Fire

Planting desirable species

Herbicides

Time

Proper grazing

Grassland quality

Fertility management

Economic value and environmental benefit

Complementary

Technologies

Retrogressive Forces
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

205

The herbicides, Plateau© and Roundup©

, have been determined to be important components of

integrated weed management strategies being developed to improve Great Plains grasslands. In

Nebraska, these herbicides have been used to (1) improve establishment of native warm-season

grasses and legumes (Beran et al. 1999a, 1999b, Rivas-Pantoja et al. 1997); (2) revegetated

leafy spurge [Euphorbia esula L.]-infested grasslands with desirable perennial forages (Masters

et al. 1996, Masters and Nissen 1998), and (3) control leafy spurge (Masters et al. 1998).

Leafy spurge is a serious threat to the productivity and biological diversity of Great Plains

grasslands. Leafy spurge was introduced from Eurasia into the northern Great Plains and Prairie

Provinces of Canada in the late 1800s. Leafy spurge is estimated to infest more than 2.5 million

acres in North America (Dunn 1979). This invasive weed reduces grassland quality by interfering

with desirable native species, reducing livestock carrying capacity, and lowering wildlife habitat

quality (Belcher and Wilson 1989). The aggressive nature of leafy spurge is related to its ability to

reproduce from seed and adventitious shoot buds on the roots and the lack of natural enemies in

North America. Seed dispersal mechanisms, high seed yields and viability, and rapid seedling

growth and development enable new infestations to quickly establish. Past management

practices have often caused undesirable shifts in species composition and hastened leafy spurge

establishment and expansion.

Biological and chemical control methods have been the focus of leafy spurge management

programs. Biological control agents used against leafy spurge include goats, sheep, and insects.

Insects including the spurge hawkmoth, flea beetles, longhorn beetle, and gall midge have been

approved for leafy spurge biological control programs in North America. It is too early to fully

assess the impact of insect biocontrol agents since most have been released within the past

seven years.

Leafy spurge control with herbicides is variable. Effective long-term control of small infestations

of leafy spurge is possible with Tordon©

 applied at 1 gallon per acre. The high cost of this

treatment limits its use to small infestations. Application of 2,4-D (2 lbs active ingredient (ai) per

acre) or 2,4-D (1 lb ai per acre) combined with Tordon (0.5 lb ai per acre) provides short-term

control of leafy spurge and reduces seed production. These herbicides selectively control

broadleaf plants including desirable native legumes and forbs. Plateau is a herbicide that has

recently been shown to provide effective control of leafy spurge, while not controlling desirable

legumes growing in leafy spurge stands.

Historically, rangeland weed management research has emphasized development of chemical

and biological control tactics. There is growing recognition that rangeland weed research should

shift from the search for a single control technology to development of integrated strategies

comprised of multiple technologies used in sequences and combinations that optimize weed

control and rangeland improvement (Scifres 1987). A goal of rangeland weed management

should be to improve degraded rangeland communities so they are less susceptible to invasion

by weeds (Masters et al. 1996; Masters and Nissen 1998; Sheley et al. 1996). Invasive weeds

appear to be symptomatic of underlying management problems that must be corrected before

sustained progress can be made toward weed control and improving rangeland productivity. One

of the concerns about simply focusing on controlling a weed in a plant community with chemical

or biological control measures is that where the weed is removed other undesirable species will

likely move into the niche vacated by the weed unless there are desirable species available to

occupy that open niche. Often rangelands have deteriorated to the point that desirable species

are either not present or in such low abundance that plant community recovery may not occur

without revegetation with desirable species.

A study was undertaken to evaluate a strategy to improve leafy spurge-infested grassland sites

near Mason City and Tilden, Nebraska. This grassland improvement strategy consisted of the

combined application of herbicides, fire, and planting mixtures of native grasses and legumes.

Plateau (0.13 or 0.19 lbs ai per acre, which is equivalent to 8 or 12 oz per acre of the 2 lb per
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

206

gallon formulation of Plateau) and Roundup (1.5 lbs ai per acre, which is equivalent to 48 oz per

acre of Roundup Ultra formulation) were applied in October 1995. These two herbicides were

selected because they are very complementary in their activity. Roundup controls cool-season

grasses that are actively growing at the time of application, but provides no residual weed control.

Plateau provides residual control of leafy spurge and annual weeds. Plateau is also tolerated by

a number of warm-season grasses and legumes. In April 1996, the sites were burned to remove

dead plant residue and the grass and legume mixtures were planted into the herbicidesuppressed sod without tillage. Leafy spurge density and yield of the vegetation including the

planted grasses and legumes were measured in August 1997.

Treatment with Plateau applied with Roundup and planting the mixture of desirable forage

grasses and legumes decreased leafy spurge abundance and dramatically increased forage yield

on the leafy spurge-infested research sites. Leafy spurge density and yield were reduced by 60%

at Mason City and 95% at Tilden where the Plateau and Roundup treatment was applied

compared to where no herbicide was applied. Application of the combined herbicides increased

forage yield of the planted grasses from 0 to 3,700 lbs per acre at Mason City and 560 to 2,800

lbs per acre at Tilden. Moreover, total vegetation yield (yield of planted species and other

remnant vegetation) increased from 2,200 to 5,700 lbs per acre at Mason City and 1,300 to 3,400

lbs per acre at Tilden where the Plateau and Roundup were applied together.

The strategy developed in this study, which involved the sequential application of Plateau with

Roundup, fire, and planting native grasses and legumes, was successfully used to reclaim the

productive potential of leafy spurge-infested rangeland at sites in the central Great Plains. The

established mixture of native species has the potential to more fully utilize resources on the leafy

spurge-infested grassland and preempt resource use by leafy spurge and other undesirable

species. By maximizing resource capture, the more diverse reestablished grassland community

should be more resistant to invasion by less desirable species. Tilman et al. (1996) determined

that plant productivity and nitrogen use were greater in more diverse plant species mixtures than

less diverse mixtures. This supports the concept that differences in resource use by multiple

plant species allows more diverse plant communities to more fully use resources and improve

overall productivity (McNaughton 1993). More diverse grassland communities should also be

more resilient and better able to sustain stable ecosystem processes over a range of

disturbances, e.g., grazing, fire, periodic droughts, etc., and return to a desirable state once

disturbances moderate.

Our goal is to provide rangeland managers with strategies that go beyond the control of

undesirable vegetation and lead to restoration of degraded rangeland communities by

reintroducing desirable native plant mixtures. Once established, it is essential to use

management systems that shift the competitive advantage to desirable species and away from

invasive species. The strategy developed in this study restores native prairie flora on degraded

rangeland sites, improves carrying capacity and native plant diversity, and decreases leafy

spurge dominance. Ultimately, management systems developed must be reliable, efficient, and

cost-effective, which is possible if multiple tools are used in appropriate combinations.

Note: Plateau is currently registered for use on roadsides and right-of-ways and not on

rangeland and pastures. The research from which these findings were obtained was supported in

part by the USDA-Agricultural Research Service, U.S. Environmental Protection Agency,

Nebraska Department of Agriculture, American Cyanamid, Monsanto, and the Arthur Sampson

Pasture Management Endowment Fund from the University of Nebraska Foundation.

References:

Beran, D.D., R.E. Gaussoin, and R.A. Masters. 1999a. Native wildflower establishment with

imidazolinone herbicides. HortSci. 34:283-286.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

207

Beran, D.D., R.A. Masters, and R.E. Gaussoin. 1999b. Grassland legume establishment with

imazethapyr and imazapic. Agron. J. 91:592-596.

Belcher, J.W. and S.D. Wilson. 1989. Leafy spurge and the species composition of a mixed-grass

prairie. J. Range Manage. 42:172-175.

Dunn, P.H. 1979. The distribution of leafy spurge (Euphorbia esula) and other weedy Euphorbia

spp. in the United States. Weed Sci. 27:509-516.

Masters, R.A., D.D. Beran, and F. Rivas-Pantoja. 1998. Leafy spurge (Euphorbia esula L.)

response to AC 263,222. Weed Technol. 12:602-609.

Masters, R.A. and S.J. Nissen. 1998. Revegetating leafy spurge (Euphorbia esula L.)-infested

grasslands with native tallgrasses. Weed Technol. 12:381-390.

Masters, R.A., S.J. Nissen, R.E. Gaussoin, D.D. Beran, and R.N. Stougaard. 1996. Imidazolinone

herbicides improve restoration of Great Plains grasslands. Weed Technol. 10:92-403.

McNaugton, S.J. 1993. Biodiversity and function of grazed ecosystems. p. 311-382 in Schulze,

E.D. and H.A. Mooney, eds. Biodiversity and ecosystem function. Springer-Verlag, Berlin.

Rivas-Pantoja, F., R.A. Masters, and D.D. Beran. 1997. Influence of planting date and herbicides

on native tallgrass establishment. Soc. Range Manage., Rapid City, SD. Abstr.

Scifres, C.J. 1987. Decision-analysis approach to brush management planning: Ramifications for

integrated range resources management. J. Range Manage. 40:482-490.

Sheley, R.L., T.J. Svejcar, and B.D. Maxwell. 1996. A theoretical framework for developing

successional weed management strategies for rangeland. Weed Technol. 10:766-773.

Tilman, D., D. Wedin, and J. Knops. 1996. Productivity and sustainability influenced by

biodiversity in grassland ecosystems. Nature 379:718-720.

ecosystems. Nature 379:718-720.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

208

Piedmont Prairie Restoration in the Charlotte, NC Area

Chris Matthews and James F. Matthews1

Abstract

The Piedmont Prairie near Charlotte, NC was possibly first reported by the Spanish explorer

Hernando de Soto in 1540 and again in 1670 by a 26-year-old German traveler named John

Lederer. Both of these men reported open “savannas” or large open areas covered by

wildflowers, grasses and few trees. The existence of these prairies is somewhat unexpected

given the Piedmont’s usual abundant rainfall that would normally support forests of large trees.

However, there is mounting evidence that these prairies may have been created by the burning

and agricultural practices of the local Native Americans communities. Piedmont Prairies are

smaller than those found in the Midwestern U.S., mostly due to the numerous creeks and streams

found in the Piedmont that act as firebreaks. Today, agriculture and urbanization, along with

European land management practices have reduced these large open areas to small remnant

isolates. Many of the prairie plants thought to have occurred in these prairies still persist along

roadsides, in utility rights-of-way, and along field edges. In an effort to restore the Piedmont

Prairie, several locations around Charlotte, NC, have been targeted for restoration projects.

Restoration involves clearing trees and shrubs, planting or enhancing prairie plant populations,

and then managing the land by periodic prescribed burning. Examples of these prairie sites

include the Shuffletown Prairie, the Mineral Springs Nature Conservancy prairie, the Anne

Springs Close Greenway Prairie sites, the Suther Prairie, the Latta Plantation Prairie, and the

McDowell Park Prairie sites. These sites all vary according to size, plant communities and

moisture regime. The restoration of these sites has all occurred because of the cooperation of

landowners, private consultants, municipality departments, the university community, and State

and Federal agencies. Several of these sites will be examined as case studies showing

restoration techniques and rationale behind the efforts.

 

1

 Habitat Assessment and Restoration Program, P.O. Box 655, Newell, NC 28126 (704) 547-4061
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

209

Developing and Evaluating Switchgrass as a Bioenergy Crop

Samuel B. McLaughlin and Marie E. Walsh1

Summary

The utilization of energy crops produced on American farms as a source of renewable fuels is a

concept with great relevance to current ecological and economic issues at both national and

global scales. Development of a significant national capacity to utilize perennial forage crops,

such as switchgrass [Panicum virgatum L.] as biofuels could benefit our agricultural economy by

providing an important new source of income for farmers. In addition, energy production from

perennial cropping systems, which are compatible with conventional farming practices, would

help reduce degradation of agricultural soils, lower national dependence on foreign oil supplies,

and reduce emissions of greenhouse gases and toxic pollutants to the atmosphere (McLaughlin

et al. 1999).

Over the past 7 years research designed to evaluate and improve switchgrass as a bioenergy

crop has been conducted by a team of government and university researchers in the

southeastern and central United States. This effort is part of the Department of Energy sponsored

Bioenergy Feedstock Development Program at Oak Ridge National Laboratory and has been

focused in the areas of yield improvement through management and breeding, physiological and

genetic characterization, and applications of biotechnology for regeneration and breeding

research. Switchgrass, a native warm season prairie grass, was chosen as the model species

because of its perennial growth habit, high yield potential, compatibility with conventional farming

practices, and high value in improving soil conservation and quality. Variety trials centered in

Virginia, Alabama, and Texas have identified three excellent high-yielding switchgrass varieties.

The varieties include Alamo, in the deep South, Kanlow at intermediate latitudes, and Indian for

the upper Midwest. Yields of fully established stands of best adapted varieties have averaged

approximately 16 Mg ha-1 in research plots across 18 testing sites, and minimum costs of $1.78-

$2.03 MBtu-1 have been estimated for farm-scale production in the Southeast.

Management research has been directed at documenting nitrogen, row spacing, and cutting

regimes to maximize sustained yields. These studies indicate that one or two-harvests per

season are best for maintaining high yields over time and that the optimum cutting frequency

depends on both latitude and switchgrass ecotype. In Texas where late season droughts are

frequent, highest yields are provided by the lowland ecotype Alamo utilizing a 1-cut system,

whereas in the Southeast and mid-Atlantic regions, highest yields of upland varieties, such as

Indian have been attained with a 2 cut-per-year system. By contrast lowland varieties such as

Kanlow and Alamo do well with either single or 2-cut systems in this region. This offers the

farmer an opportunity for flexible harvesting regimes within and between years that should help

optimize use of equipment.

The timing of harvesting is critical to optimizing and maintaining high yields. In Alabama delaying

the initial cut until July, resulted in an approximate doubling of average yield of a 2-cut system

with Alamo switchgrass over 5 years. Late season cuts, after October, typically result in up to

20% yield loss associated with retranslocation of carbohydrates and mineral nutrients, notably

nitrogen, back into the root system. An additional factor favoring the single cut system is the

reduction of up to 60% in usage of nitrogen associated with harvesting mature vs. the more

 

1

 Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN. The research

described in this paper was sponsored by the Biofuels Systems Division of the U.S. Department

of Energy, under contract No. DE-ACO5-96OR22464 with Lockheed Martin Energy Research

Corp. This summary condenses and augments portions of a recent paper by McLaughlin et al

(1999)
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

210

succulent tissues that are included in the 2 cut regime. Lower ash content, particularly

potassium, associated with late season harvest also results in improved suitability of this material

for combustion in power generation systems (Sanderson and Wolf 1995 and McLaughlin et al.

1996).

Significant gains in soil carbon have been documented for a wide range of sites under

switchgrass and associated gains in soil quality and erosion control are anticipated in connection

with long term production of this species (McLaughlin et al. 1994). Recent studies of the

dynamics of soil carbon indicate that switchgrass contributes both labile (3-5 yr. turnover) and

relatively stable (26-40 yr. turnover) forms of carbon to soil carbon pools. Total carbon gains in

degraded agricultural soils have been estimated at 12 % over a 10-year period (Garten et al.

1999)

To date switchgrass has been bred primarily to enhance its nutritional value as a forage crop for

livestock (Vogel et al. 1989). Thus, it has been managed primarily as a hay crop for which high

leaf to stem ratio and high nutrient content are important. These targets are quite different from

the criteria for biofuels crops for which high cellulose and low ash content are important for high

energy conversion and low contamination of combustion systems, respectively. Breeding

research has focused on developing and characterizing an extensive germplasm collection,

characterizing breeding behavior traits, and both narrow and broader base selection for yield

improvement for both marginal and better quality soils (Taliaferro et al. 1999). Breeding gains of

>5% per breeding cycle (3-4 yr.) have been indicated with improving techniques for narrow base

genetic selection and associated heterotic gains. Tissue culture techniques have now been

developed (Denchev and Conger 1994) to permit rapid clonal propagation of select switchgrass

lines and to offer opportunities for application of advanced biotechnological tools such as gene

transfer (Denchev and Conger 1996).

Energy budgets indicate that significant gains in net energy return and carbon emissions

reduction can be achieved by utilizing switchgrass as a biofuel (McLaughlin and Walsh 1998).

These gains are associated with the low energy demands of growing and harvesting perennial

grasses, high nutrient and water use efficiency, and the fact that the whole aboveground plant

can be converted to energy products. In addition the increased storage of carbon belowground

provides a second avenue for reducing net carbon emissions to accompany reductions in direct

C02 emissions associated with supplanting fossil fuels with renewable energy derived from

atmospheric carbon.

The bioenergy industry is still in its infancy in terms of its impacts on national energy use.

However, the potential of biofuels to contribute to a national energy strategy is substantial. The

benefits to the nation of providing cleaner burning fuels that improve both regional and global air

quality while improving soil and water quality should be obvious. A multiagency task force is

currently conducting analyses with an agricultural sector model (POLYSYS) to estimate the

capacity of switchgrass at current production levels and costs to penetrate conventional

agricultural markets (Walsh et al.1998). The most recent analyses with this approach project

that, at a price of $30 per ton for switchgrass, improved economic returns would be realized on

approximately 17 million acres of agricultural land compared to current returns from conventional

crops grown on these lands. At a price of $40 per ton for switchgrass economic gains are

projected on 42 million acres. With the improvements in the farm economy, which can be

expected with the production of energy on American farms and associated increased income for

American farmers, bioenergy crops offer a "win-win" option for the planners of Americas future

energy strategy. Bioenergy crops can be expected to become increasingly competitive in the

future as the diversity of products possible from reformulation of biochemical constituents is

developed through processes such as gasification and bioreactor technology. There are

promising signs that the utility industry has recognized the value of cleaner burning renewable

fuels, which reduce environmental and political liabilities associated with relying totally on fossil

fuels. Attainment of the potential for significantly greater participation of biofuels in national

energy supply curves will require continued research on producing and improving energy crops
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

211

more economically, continued improvement of the bioconversion technology to increase the

diversity and value of end products, and a commitment of policy makers to improvement of

environmental quality, which is measured in both long and short- term time frames.

References

Denchev. P.D. and B.V. Conger. 1996. Gene transfer by microprojectile bombardment of

switchgrass tissues In Vitro Cell Dev. Biol. 32(3) Part II. p. 98A.

Denchev, P.D. and B.V. Conger. 1994. Plant regeneration from callus cultures of switchgrass.

Crop Sci. 34:1623-1627.

Garten C.T. and S.D. Wullschleger 1999. Soil organic carbon dynamics beneath switchgrass as

indicated by stable isotope analysis. J. Environ. Qual. (In press).

McLaughlin, S.B., D.I. Bransby, and D. Parrish. 1994. In: Bioenergy 94 Proc. Perennial grass

production for biofuels: soil conservation considerations. p. 359-370. Reno , NV, Oct. 1,

McLaughlin, S.B., R. Samson, D. Bransby, and A. Weislogel. 1996. Proc. Bioenergy 96,

Evaluating Physical, Chemical, and Energetic Properties of Perennial Grasses as Biofuels.

Nashville, TN, Sept. 1996, p. 1-8.

McLaughlin, S.B. and M.E. Walsh. 1998. Evaluating Environmental Consequences of Producing

Herbaceous Crops for Bioenergy. Biomass and Bioenergy 14:317-324

McLaughlin, S.B., J. Bouton, D. Bransby, B. Conger, W. Occumpaught, D. Parrish, C. Talliaferro,

K. Vogel, and S. Wullschleger. 1999. Pp. 282-299 in J. Janick, ed. Developing Switchgrass as a

Bioenergy Crop. In Proc. Fourth National New Crops Symposium, Nov. 8-11, 1998, Phoenix, AZ.

Taliaferro, C.M., K.P. Vogel, J.H. Bouton, S.B. McLaughlin, and G.A. Tuskan. 1999 Reproductive

characteristics and breeding improvement potential of switchgrass. Pp. 147-153 in Proceedings

of Fourth Biomass Conference of the Americas, Aug 29 -Sept 2, 1999, Oakland CA.

Sanderson, M.A. and D.D. Wolf. 1996. Morphological development of switchgrass in diverse

environments. Agron. J. 878:908-915.

Vogel, K.P., H.J. Gorz, and F.A. Haskins. 1989. Breeding grasses for the future. Crop Sci. Soc.

Amer. Contrib. from Breeding Forage and Turf Grasses, CSSA Special Pub No. 15.

Walsh, M.E., D.D.T. Ugarte, S. Slinsky, R.L. Graham, H. Shapouri, and D. Ray. 1998. In Proc

Bioenergy 98 Economic analysis of energy crop production in the U.S.- Location, quantities,

price, and impacts on traditional agricultural crops, Oct 9. Madison WI.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

212

Native Warm-Season Grass Establishment as Affected by Weed Control in

the Maryland Coastal Plain

Gwen C. Meyer1, Norman C. Melvin III,2 Thomas R. Turner3, and Harry J. Swartz3

Abstract

There are numerous warm-season grass (WSG) species native to the Mid-Atlantic Coastal Plain

of Maryland. However, few regional species are commercially available and little research has

focused on their successful direct seeding establishment. Reliable establishment research

procedures for native WSG species will promote their use in ecological restoration, soil

conservation, and summer pastures of the region. Because weed control is often critical to WSG

establishment, our objective was to evaluate the effect of four weed control practices on

establishment of beaked panicum [Panicum anceps Michx.], purpletop [Tridens flavus (L.)

Hitchc.], and Indiangrass [Sorghastrum nutans (L.) Nash] collected in the Mid-Atlantic Coastal

Plain. Treatments used for 2-yr establishment study at two sites were 1) infrequent mowing

regime (once per season), 2) frequent mowing regime, 3) frequent mowing in the first year with a

broadleaf herbicide mixture (2,4-D, MCPP, and Dicamba) applied in the second year, 4) frequent

mowing in the first year with an imidazolinone herbicide applied in the second year, and 5) a

control. Stand density (m2

) was recorded in September of the seeding year and monthly from

June through September during the second growing season at both research sites. Indiangrass

averaged a minimum stand density of 11 or more plants m-2 with all weed control practices

including the control. Results indicate that all weed control treatments produced significantly

higher stand densities as well as higher tiller numbers than the control. Therefore, even minimal

weed control, such as one mowing per season, significantly reduced weed competition improving

WSG stand establishment in the Mid-Atlantic Coastal Plain over two growing seasons for the

species tested.

Introduction

Warm-season native grasses often are slow to establish the year they are seeded because of

factors such as seed dormancy, lack of soil moisture (Hyder et al. 1971), and delayed

development of an adventitious root system (Whalley et al. 1966; Newman and Moser 1988). In

determining the success of native WSG plantings, a major determining factor is control of weed

competition prior to and following seeding. Inadequate weed suppression causes more WSG

seeding failures than any other single factor, and failure to address a weed problem will result in

failure or a substandard grass stand (Duebbert et al. 1981; Mathis et al. 1971). Weed control is

critical during establishment of warm-season grasses since weeds shade the developing grass

seedlings and contribute to decreasing permanent root development (Wilson 1984).

After planting WSG seed, weed control practices are generally needed to provide reduction of

weed competition. Most perennial native WSG species are susceptible to weed competition in the

seedling stage, because of low seedling vigor and slower growth in comparison to annual weed

species. Furthermore, when annuals are given an initial advantage, they quickly dominate the

planting. Hsu and Nelson’s (1986) 2-year study showed that the annual weed, crabgrass

[Digitaria sanguinalis L. Scop.], developed more tillers, more leaves per plant, more leaf area, and

accumulated more dry matter than did perennial warm-season grasses. This suggests that

crabgrass competes strongly with perennial native WSG species during seedling development in

 

1

 USDA, Natural Resources Conservation Service (NRCS), National Plant Materials Center,

Building 509 BARC-East, Beltsville, Maryland 20705. 2

 USDA, NRCS, Wetland Science Institute,

11400 American Holly Drive, Laurel, Maryland 29708-4014. 3 Department of Natural Resource

Sciences & Landscape Architecture, University of Maryland, College Park, Maryland 20742.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

213

the field. They further stated that young weeds removed after emergence reduced grass seedling

performance compared to preventing weed emergence.

A cultural weed control practice proposed by Launchbaugh and Owensby (1978) in the Midwest

is grazing first-year grass plantings where the seedlings and weeds serve as a resource for

livestock. However in sub-humid and humid environments, grazing treatments over a two-year

period resulted in inadequate stands (fewer than 11 plants m-2) of the WSG big bluestem

[Andropogon gerardii Vitman] (Lawrence et al. 1995). Lawrence et al. concluded that grazing was

not a suitable alternative to chemical suppression for weed control where high weed populations

exist.

Mechanical weed control by mowing can accomplish several things such as nutrient recycling of

standing vegetation, grass tiller recruitment, providing mulch for bare areas, and reduction of

annual weed competition for light. Clipping should be completed after sufficient weed growth, so

that the most active growth buds of weeds are removed. Additionally, pasturing or clipping new

grass seedings is helpful but both should end 4-6 weeks before a killing frost (Vough et al. 1995).

If the WSG tiller is vegetative when cut, the undamaged intercalary meristem at the base of the

plant continues to differentiate blade tissue. Weed can be controlled in a first year tall-grass

prairie native grass planting by mowing when weeds reach a height of 31-46 cm to prevent them

from forming seed (Ohlenbusch 1997). Flail mowers, sickle bar mowers, and rotary mulching

mowers have all been successful at uniformly distributing clippings. If proper mowing equipment

is not available, an option is to bale clippings. Another type of mechanical weed control used in

the seed production industry is interrow cultivation (Smith and Smith 1997) which can take place

when rows of native grass are visible. This type of cultivation should not be closer than one inch

to the planted row so grass seedlings are not disturbed.

Herbicides labeled for pre- and post-emergence use in native grass seedings are limited and their

use is often dependent on growth stage of the grass plant. The non-selective herbicide

glyphosate [N-(phosphonomethyl)glycine], can be used anytime prior to seedling emergence to

control perennial grasses and broadleaf weeds. The broad-spectrum herbicide atrazine [6-chloroN-ethyl-N-(1-methylethyl)-1,3,5-triazine-2,4diamine] has also been applied pre-emergence to

native grass seed germination (Vassey et al. 1985). For post-emergence broadleaf weed control

2,4-D [2,4-dichlorophenoxy)acetic acid], dicamba [3,6-dichloro-2-methoxybenzoic acid] and

MCPP [2,2(2-methyl-4-chlorophenoxy) propionic acid] are commonly used and are labeled for

use only after native WSG seedlings reach the three to five leaf stage. The practice of postemergence wicking or wiping with a nonselective herbicide requires that the weeds are taller than

the desirable grass crop to be effective (Smith and Smith 1997).

Imazapic (Plateau) [(+)-2-[4,5-dihydro-4-methyl-4- (1-methylethyl)-5-oxo-1H-imidazol-2-yl]-5-

methyl-3-pyridinecarboxylic acid] is a broad-spectrum herbicide released in 1997 for weed control

and growth suppression in non-crop areas (American Cyanamid 1997). Imazapic can be used in

many native grass and wildflower plantings and is labeled for pre- or post-emergence control of

broadleaf weeds and some perennial and annual grasses. Application rates vary depending on

application timing, soil type, preferred native species, and weed species to control. It is readily

absorbed through leaves, stems, and roots and is rapidly translocated through the plant with

accumulation in meristematic regions (American Cyanamid 1996).

Establishment of native grasses and selected forbs using varying rates of three imidazolinone

herbicides show improved establishment of native grasses, especially with pre-emergence

treatment as opposed to post-emergence treatment (Masters et al. 1996). It was concluded that

imidazolinone herbicides could be important components of integrated weed management

strategies to reverse deterioration of grasslands, improve grassland productivity, and decrease

exotic weeds. However, a major disadvantage for post-emergence application is that often there

is limited time when herbicides are effective due to the growth stage restrictions of weeds to be

controlled.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

214

Advantages of planting native warm season grasses in the Mid-Atlantic Coastal Plain are that

they grow well in acid soils, are more efficient in the use of water, N and P, maintain growth at

higher temperatures than cool-season grasses, and provide soil conservation and restoration

benefits (Stout et al. 1986, 1988; Jung et al. 1988, 1990; Brejda et al. 1995; Moser and Vogel

1995). While WSG establishment data exist for more mesic sites, establishment of seeded native

WSG species under different weed control practices is lacking in the humid region of the MidAtlantic Coastal Plain. The research objective was to determine if significant differences in

establishment of three native WSG species exist with four weed control treatments in the Coastal

Plain of Maryland.

Methods

Site Characteristics

The study was duplicated at two University of Maryland research facilities. The Turfgrass

Research and Education Facility in Silver Spring, MD is located in the northern coastal plain (Soil

Conservation Service 1981) and Plant Hardiness zone 6b. Soil is a Rumford loamy sand (coarseloamy, siliceous, subactive, thermic Typic Hapludults) with a pH of 6.1 and 1.5% organic matter.

Soil texture is 89% sand, 6% silt, and 5% clay for the Turfgrass farm. Initial soil P, K, and Mg

levels were 177, 74 and 209 kg ha-1, respectively. Nitrate (NO3) levels were 21 kg ha-1.

Precipitation at the Turfgrass farm from May to September 1996 was 850 mm (301 mm above the

average) and 350 mm (199 mm less than average) for the same period during 1997.

The second study site was the University of Maryland Wye Research Center in Wye Island, MD

located in the Mid-Atlantic Coastal Plain (Soil Conservation Service 1981) and Plant Hardiness

Zone 7a. Soil is a Mattapex silt loam (fine-silty, mixed, mesic Aquic Hapludults) with a pH of 6.5

and 3.5% organic matter. Soil texture is 38% sand, 50% silt, and 12% clay. Initial P, K and Mg

levels were 319, 504 and 300 kg ha-1, respectively and nitrate levels measured at 55 kg ha-1.

Precipitation at the Wye farm in 1996 from May to September was 600 mm, and for the same

period during 1997 was 480 mm. Prior to this study, Festuca arundinacea Schreb. (tall fescue)

was maintained at both research sites.

Species Selection and Planting

The perennial WSG species chosen were common to the coastal plain region, had direct seeding

capabilities, wildlife value, known restoration benefits, and good seed availability. Seed of the

WSG species were hand collected from local native Maryland coastal plain populations during the

fall of 1995. Seed of each species was collected from more than 30 plants with no preference for

any traits such as height, larger seed heads, etc. After collection, species symbols (USDA NRCS

1997) and accession numbers were assigned for identification and tracking. Seed viability using

the tetrazolium (TZ) method (USDA 1961) and purity were evaluated by the Maryland Department

of Agriculture Seed Testing Lab (Table 1). The three native species were beaked panicum and

purpletop, both collected in Prince George’s County, MD and Indiangrass collected in Queen

Anne’s County, MD. To aid in planting, collected seed was cleaned by various methods of hand

rubbing and passing through sieves. Beaked panicum was moistened and cold stratified at 40

 C

for three weeks prior to planting to break dormancy (Mathew 1942). The three species were

individually weighed and 100 seed weights were determined from averages of three separate

measurements (Table 1).

Based on the normal rainfall of the region and the planned broadcast seeding technique, a

seeding rate of 431 pure live seed (PLS) m-2 (40 PLS seed ft.-2) was selected (Wark et al. 1995;

Nelson and Shepherd 1940). In addition to filed plantings, all species were individually seeded in

cell packs in the greenhouse. This enabled observation of the emerging and developing grass

seedlings to aid in field identification. The study was initiated in 1996 by spraying existing tall

fescue vegetation with 6.72 kg ha-1 glyphosate on 12 April at the Wye farm (17 d before seeding)

and 15 April at the Turfgrass farm (10 d before seeding). One week after spraying, both sites
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

215

were moldboard plowed, disked, and packed twice by a solid wheel packer to achieve a firm

seedbed (Thornburg 1982). Plots measured 2 x 2 m with three replicates of the four weed

treatments and the control at each site.

Table 1. Warm-season native grass symbols, classification, seed purity, viability, and

weights.

Genus Common Name Symbol Wetland

Classification

TZ†

%

Purity

%

PLS‡ 100 Seed

Wg (g)

Panicum anceps Michx. beaked panicum PAAN FAC 25 98 25% 0.079

Sorghastrum nutans (L.)

Nash 

Indiangrass SONU2 UPL 100 37 37% 0.141

Tridens flavus (L.) Hitchc. purpletop TRFL2 FACU 100 99 99% 0.073

†TZ = tetrazolium test that visibly stains viable seeds

‡PLS = Purity of seed lot multiplied by germination divided by 100

The grasses were individually broadcast seeded using a spring planting date (Hsu and Nelson

1986; Panciera and Jung 1984; Vassey et al. 1985) into a clean-tilled seedbed on 25 April 1996

at the Turfgrass farm on 29 April 1996 and at the Wye farm. For ease of spreading seed, WSG

seed was mixed with small amounts of a white granular cacined clay oil absorbent (Associates

Absorbents Association, High Point, NC). Grass seed was broadcast planted by shaking evenly

over each plot from a jar with 6-mm holes in the lid. After seeding, each plot was raked lightly to

obtain a shallow soil cover over the seed, and hand rolled twice with a metal, water-filled 189-L

drum to obtain good seed-to-soil contact. No supplemental irrigation was applied at any time

during the study and no herbicides were applied in 1996 growing season.

Weed Control Treatments

The four weed control treatments were 1) mowing once per season to 10 cm ht, 2) frequent

mowing to 10 cm ht without herbicide, when weeds reached 31-46 cm, 3) frequent mowing in the

first year plus a prepackaged broadleaf herbicide mixture of 2,4-D, dicamba, and MCPP

(Dernoden et al. 1994) applied in the second year, and 4) frequent mowing in the first year plus

imazapic herbicide applied in the second year. The herbicide treatments applied during the

second growing season replaced mowing at both research sites. The broadleaf herbicide mixture

applied in the second year was labeled for post-emergence broadleaf weed control in native

WSG. Imazapic was labeled for non-cropland pre-emergence weed control during the

establishment of native warm season grasses. Imazapic controls weedy perennial and annual

grasses in addition to broadleaf weeds. Herbicides were not used until the second year because

the broadleaf herbicide mixture was labeled for WSG seedlings at the 3-5 leaf stage or beyond. It

is common to wait until fall of the seeding year or the second growing season for WSG seedlings

to reach the stage where a broadleaf herbicide can be used. Imazapic labeled for establishment

of WSG was not available until 1997 so was not used until the second year as a post-emergence.

Weed control treatments that included mowing utilized a self-propelled rotary mower. Mowed

weed control treatment plots were cut to an approximate height of 10 cm above the soil surface

during both growing seasons. The frequent mowing treatment was completed whenever weed

cover reached a height of 31-46 cm to reduce competition with the WSG and before most weeds

produced seeds. The infrequent mowing treatment was applied once per year at mid-season. No

clippings were removed during two growing seasons.

The 1997 second year herbicide treatments were each applied post-emergence at both research

study sites. The broadleaf 2,4-D, dicamba and MCPP herbicide mix was applied at a rate of 1.8

kg ha-1 on 2 May 1997 at the Wye farm and on 8 May 1997 at the Turfgrass farm. The imazapic

herbicide treatment was applied on 2 May 1997 at a rate of 0.113 kg ai ha-1 at both research sites
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

216

according to label recommendations. All herbicide treatments were applied with a Walkover (Allen

Power Equipment Ltd., Didcot, England) push sprayer with a 3.8-L tank. The control was

untreated during two growing seasons at both research sites. Throughout the 1996 and 1997

seasons, a 2.54-cm-wide line of glyphosate was sprayed approximately every month on the

outside border of each 4 m2 plot in order to keep clear delineation between research plots

Stand density data were collected the seeding year on 26 Sept 1996 and on four dates in 1997 at

each research site. Stand density data were collected randomly in each plot by counting

individual germinated seedlings in a sample m2

 PVC square. In the second growing season of

1997, individual plant density and tiller density (total number of stems per plant) data m2 were

collected and recorded at four measurement dates at approximately 30-day intervals from June

through September. Percent weed cover per treatment was estimated during 1997 and weed

species were recorded.

Experimental Design

Stand densities from the two research sites were analyzed separately for the second growing

season as a randomized split-block design. Whole plots consisted of three WSG species with

subplots of four weed control treatments and a control, with three replications. Stand density data

for 1997 were analyzed (p<0.05) using the mixed model analysis of variance (ANOVA) procedure

in SAS version 6.12 (1996) to partition experimental variance. Repeated-measures analysis

(ANOVA) was used for covariance between multiple samples on the same experimental unit

throughout the 1997 growing season. Orthogonal contrasts were an independent analysis

between weed control treatments at both research sites. Means for September 1996 stand

density measurements show plant development differences after one growing season. However,

these data are not part of the final analysis since all treatments were not applied until the second

growing season in 1997.

Results and Discussion

1996 Stand Densities

At 144 d after seeding at the Turfgrass farm, beaked panicum had not germinated, Indiangrass

had a mean stand density of 17.2 plants m-2, and purpletop a mean stand density of 0.32 plants

m-2. Mean stand densities at the Wye farm at 154 d were 0.65 plants m-2 for beaked panicum,

13.9 plants m-2 for Indiangrass, and 2.15 plants m-2 for purpletop. No herbicides were applied until

the second growing season (1997). At the Wye site only one treatment with beaked panicum had

any germination, and only two treatments with purpletop had any germination (Table 2).

Stand Density at the Turfgrass Farm-1997

Stand densities were significant for the main effects of date and species. Indiangrass was the

only species to produce 11 or more plants m-2 by the July 1997 date as a measure of successful

establishment (Dickerson and Wark 1997) (Table 3). The highest mean tiller number was for the

frequent mow the first year with imazapic herbicide in the second year treatment, with an average

of 118.4 tillers m-2. The next highest mean tiller number was for the infrequent mowing treatment

with 99.0 tillers m-2, followed by the frequent mowing treatment, then the frequent mow the first

year with 2,4-D, dicamba, and MCPP herbicide in the second year treatment with means of 86.9

and 88.2 tillers m-2, respectively. Lastly the control had a mean tiller number of 33.1 m-2. Percent

weed cover at the Turfgrass farm in 1997 was the highest for the control (Table 4) and was

lowest for the frequently mowed treatment in the first year with imazapic herbicide in the second

year.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

217

Table 2. Stand density means for Turfgrass farm and Wye farm on 26 September 1996 N=3.

Treatment Species Turfgrass Farm Wye Farm

Plants m-2

Control

beaked panicum 0.0 0.0

Indiangrass 15.3 25.1

purpletop 0.0 0.0

Frequent mow both years

beaked panicum 0.0 0.0

Indiangrass 16.1 7.2

purpletop 0.0 0.0

Frequent mow the first year + 2,4-D, dicamba, MCPP the second year

beaked panicum 0.0 0.0

Indiangrass 14.3 10.8

purpletop 0.0 3.58

Frequent mow the first year + imazapic the second year

beaked panicum 0.0 3.58

Indiangrass 20.7 18.0

purpletop 1.80 3.58

Infrequent mow both years

beaked panicum 0.0 0.0

Indiangrass 18.0 10.8

purpletop 0.0 0.0

Table 3. Plant densities for all species in 1997 by treatments N=36.

Treatment Turfgrass Farm Wye Farm

Plants m-2 ± SE

Control 8.37 ± 2.88 6.58 ± 1.42

Frequent mow both years 17.90 ± 2.88* 12.30 ± 1.79*

Frequent mow the first year + 2,4-D, dicamba,

MCPP the second year

15.00 ± 2.88* 16.11 ± 1.79*

Frequent mow the first year + imazapic the

second year

18.50 ± 2.88* 11.90 ± 1.62*

Infrequent mow both years 20.10 ± 2.88* 8.37 ± 1.79*

* significant at 0.05 probability level
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

218

Table 4. Weed cover for 1997 treatments N=36.

Turfgrass Farm Wye Farm

Treatment weed cover % ± SE

Control 75 ± 2.56 90 ± 1.17

Frequent mow both years 58 ± 2.66 88 ± 0.87

Frequent mow the first year + 2,4-D, dicamba,

MCPP the second year

58 ± 4.48 91 ± 1.11

Frequent mow the first year + imazapic the

second year

17 ± 1.05 79 ± 1.01

Infrequent mow both years 62 ± 3.35 73 ± 3.33

Stand Density at the Wye Farm-1997

Tests of fixed effects resulted in a significant interaction between plant densities and

measurement dates and between plant densities and weed control treatments. The beaked

panicum had significant treatment results of 12.6 ± 2.92 plants m-2 with frequent mowing the first

year, 2,4-D, dicamba, and MCPP herbicide the second year and with infrequent mowing both

years that had a stand density of 7.18 ± 3.06 plants m-2 (Table 5). During the 1997 growing

season at the Wye farm, the Indiangrass yielded 11 or more plants m-2 with all weed control

treatments including the control, and all treatments were significant (Table 5). The highest stand

density for Indiangrass at the Wye farm was from the frequent mowing in the first year with

imazapic herbicide in the second year treatment producing 24.2 ± 2.34 plants m-2. All weed

control treatments produced significantly different plant densities for purpletop during the 1997

growing season (Table 5). The weed control treatment of frequent mowing in the first year with

2,4-D, dicamba, and MCPP mix herbicide in the second year had the highest stand density

means for purpletop with 16.1 ± 4.08 plants m-2.

Orthogonal contrasts for all treatment results at the Wye farm in 1997 indicated that stand

densities for the control were significantly lower than all weed control treatments (Table 3). In

addition, stand density for the infrequent mowing treatment was significantly lower than the other

three weed control treatments. Species tiller number m-2 means were highest for the frequent

mow in the first year with 2,4-D, dicamba, and MCPP herbicide mix the second year treatment

with an average of 82.2 tillers m-2 followed by the frequent mow in the first year with imazapic

herbicide the second year treatment with 65.4 tillers m-2. The frequent mow for both year

treatment and the control produced mean tiller numbers of 36.2 and 33.1 m-2, respectively. The

infrequent mowing treatment had the lowest mean tiller number with 27.2 m-2. From observation

at each date, the highest weed cover percentages during 1997 were for the control and the

frequent mowing in the first year with 2,4-D, dicamba, and MCPP herbicide mix in the second

year treatment (Table 4), with the lowest weed cover percentage for the infrequently mowed

weed control treatment.

Conclusions

Results of weed control treatments varied depending on the WSG species. During the second

growing season after direct seeding, the control always had lower stand densities than any of the

four weed treatments at both Mid-Atlantic Coastal Plain research sites. When observing the

significant interaction between species stand densities and treatments at the Wye farm in 1997

(Table 5), both beaked panicum and purpletop stand densities were highest with the treatment of

frequent mowing the first year followed by 2,4-D, dicamba, and MCPP herbicide mix applied the

second year following direct seeding. Indiangrass stand density was highest with the treatment of

frequent mowing the first year followed by imazapic herbicide applied the second year following

direct seeding. At the Turfgrass farm there were no significant differences between any weed

control treatments (Table 5). Imazapic is not labeled for use in switchgrass during seedling
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

219

establishment (American Cyanamid 1997), and potentially adversely affected the beaked

panicum establishment with the June 1997 application at each site.

Table 5. Species x treatment interaction for Wye farm in 1997 N=2.

Treatment Species Wye Farm

Plants m-2 ± SE

Control beaked panicum 0.0 0.0

Indiangrass 17.9 ± 2.75* 24.3 ± 6.01

purpletop 1.2 ± 1.10 0.0

Frequent mow both years beaked panicum 3.6 ± 2.03 5.4 ± 1.61

Indiangrass 20.7 ± 2.79* 37.8 ± 1.62

purpletop 12.6 ± 3.45* 10.9 ± 2.23

Frequent mow the first year + 2,4-D,

dicamba, MCPP the second year

beaked panicum 12.6 ± 2.92* 3.6 ± 1.52

Indiangrass 19.7 ± 2.23* 35.1 ± 4.23

Purpletop 16.1 ± 4.08* 6.3 ± 2.08

Frequent mow the first year +

imazapic the second year

beaked panicum 0.0 1.7 ± 1.21

Indiangrass 24.2 ± 2.34* 47.6 ± 8.87

purpletop 11.6 ± 2.80* 6.3 ± 2.01

Infrequent mow both years beaked panicum 7.2 ± 3.06* 3.6 ± 1.52

Indiangrass 11.6 ± 2.46* 42.3 ± 6.34

purpletop 6.3 ± 2.08* 13.5 ± 5.00

*significant at 0.05 probability level

The three perennial native WSG species tested germinated and established with all weed control

treatments producing significantly greater stand densities than the controls at each study site.

Therefore, even minimal weed control provided reduced competition to improve WSG stand

establishment in the Mid-Atlantic Coastal Plain over two growing seasons when compared to the

control. Neither beaked panicum nor purpletop established significant stand densities in the

control in the second growing season at either research site. In contrast the Indiangrass

established significant stand densities in the control (more than 11 plants m-2) at both research

sites during 1997, showing that this WSG species can establish to minimum success levels with

no weed control in this region.

Mean tiller numbers were also significantly higher during the second growing season with all

treatments tested in contrast to the control. Therefore, there are options in the Mid-Atlantic

Coastal Plain of Maryland when choosing native WSG weed control measures depending on the

planting site, severity of weed competition, native WSG species selection and available

resources. Additional weed control research would be beneficial to test imazapic as a preemergence herbicide treatment for collected WSG species, as imazapic was not commercially

available prior to the planting dates for this research study.

Acknowledgments

Research support provided by Dr. Billy Teels, Director of NRCS Wetland Science Institute in

Laurel, MD through Cooperative Agreement NRCS 68-3B-19-5-267 with the NRCS Maryland

State Office.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

220

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222

The Use of Native Warm Season Grasses for Critical Area Stabilization

Christopher F. Miller1 and John A. Dickerson2

Native warm season grasses are indigenous to the Northeastern United States but now are found

growing naturally only in isolated pockets throughout the region. When Europeans arrived on the

continent, there were some impressive grasslands contained within the eastern forest, primarily in

burned areas and in “barrens” or rocky outcrops. Now, the most extensive remnants are found

along the coastal strip/barrier islands, railroad/utility rights-of-way and in natural areas along

major river systems. The most common warm season grasses found include: switchgrass

[Panicum virgatum L.], coastal panicgrass [Panicum amarum Elliott], big bluestem [Andropogon

gerardii Vitman], little bluestem [Schizachyrium scoparium (Michx.) Nash], Indiangrass

[Sorghastrum nutans (L.) Nash], deertongue [Dichanthelium clandestinum (L.) Gould], purpletop

[Tridens flavus (L.) Hitchc.], eastern gamagrass [Tripsacum dactyloides (L.) L.], sideoats grama

[Bouteloua curtipendula (Michx.) Torr.], and the cordgrasses [Spartina spp.].

These native warm season grasses provide extremely valuable habitat for ground-nesting birds

and many mammals. They are very deep rooted, making for long lasting, stress tolerant, low

maintenance plants. The root biomass of native warm season grasses far exceeds that of the

introduced cool season grasses. This characteristic provides increased organic matter in soils

and more rapid infiltration rates. The bunch-type habit of these grasses provides space for the

inclusion of native forbs and legumes to further improve habitat quality. Although these attributes

of the native grasses are well documented, there has been a reluctance to utilize them in the

Northeast, particularly for the purpose of erosion control.

The Northeast has a long history of utilizing introduced cool season turf and forage grasses for

erosion control. Introduced cool season grasses such as perennial ryegrass [Lolium perenne L.],

Kentucky bluegrass [Poa pratensis L.], tall fescue [Festuca arundinacea Schreb.], and

orchardgrass [Dactylis glomerata L.], are readily available, relatively inexpensive and have good

seedling vigor which is useful for quick stabilization. In addition, the cool season grasses may be

seeded almost year-round, except during the typical midsummer dry period. Conversely, the

native warm season grasses are not as readily available, are more expensive, and have relatively

low seedling vigor compared to cool-season grasses, which results in a longer establishment

period.

There are other reasons for reluctance to using warm season grasses. A warm season grass

seedling partitions initial energy into root development so seedlings are vulnerable to competition

and frost heave until the end of the second growing season. The primary seeding window is

limited to the early spring, but late fall/early winter seedings are a possible option on droughty

soils with little weed competition. There is no late summer/early fall seeding window as with cool

season grasses. Many of the warm season grasses produce chaffy seeds with long awns, which

do not efficiently flow through a conventional grass seeder. As a result, specialized seed drills,

which handle this type of seed, are needed, but have not been commonly available in the

Northeast. However, recent purchases of native grass seed drills by Soil Conservation Districts,

grass-roots environmental and wildlife organizations, and the U.S. Fish and Wildlife Service have

greatly improved the availability of native grass drills in the Northeast region.

In general, warm season grasses have more exacting requirements for establishment than do

cool season grasses. However, the benefits of utilizing the native grasses far outweigh the

potential difficulties encountered. This article intends to minimize the concerns with establishing

native warm season grasses for erosion control by presenting recommendations which have

proven to be successful in the Northeast for the last eighteen years.

 

1 USDA-NRCS Plant Materials Specialist for Southern New England/Mid Atlantic Area

2

USDA-NRCS Plant Materials Specialist for New York/Northern New England
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

223

Site Selection

Suitable planting sites for warm season grasses have the following attributes:

1. Soil drainage class of moderately well drained or better, with no history of frost heave.

Frost heave is less of a threat in states with longer and/or warmer summers than we have in New

York, Vermont, New Hampshire, Maine, Massachusetts, and southeastern Canada. Even within

the frost heave area, sandy or gravely soils rarely have this problem.

2. Good control of perennial cool season grasses and forbs. Weed competition is typically

much lower on critical area stabilization sites such as mined areas, sanitary landfill caps, and

other disturbed areas due to poor soil conditions.

3. At least a 100-day frost-free season, and 1600 growing degree days (corn formula).

4. Full sun with south, west and east exposures at elevations below 2000 feet in plant

hardiness zone 3 or warmer. A northern exposure limits elevations to below 1500 ft. and to slopes

of less than 20 degrees in plant hardiness zone 4 or warmer. Add 500 feet to elevation limits for

each warmer hardiness zone.

5. Soil pH of 5.5 or higher with moderate or low N, P, K.

Site Preparation

The area to be planted should be firm and free of weeds, large rocks, stumps and other debris

over 2” in diameter.

Weed competition is typically not a problem on critical area planting sites due to the sterile,

droughty soil conditions which often exist in disturbed areas. However, perennial cool season

grasses pose the biggest threat to warm season grass establishment and must be addressed the

year prior to planting if they are present. Contact herbicides such as Roundup, Poast, Fusilade,

Gramoxone, 2,4-D, and Banvel combined with tillage, are effective ways to eliminate perennial

weeds. All herbicides must be used according to the label requirements.

Planting Procedure

Switchgrass, coastal panicgrass, and deertongue can be planted with conventional grass or grain

seeding equipment because the seed will meter through the feed mechanisms. The bluestems,

Indiangrass, and sideoats grama have chaffy seed which requires either broadcasting or a native

grass drill with “picker wheel” feed mechanisms and hopper agitation. Eastern gamagrass can be

planted with a corn planter if a forage stand is desired.

Drills should be set to plant 0.25 to 0.5 inch deep. Depth bands help with this, otherwise careful

adjustment of the drill pressure is required. Eastern gamagrass does best at depths of 1 to 1.5

inches.

In the Northeast, availability of native grass drills has been minimal. In addition, some sites do not

lend themselves to drilling because of slope steepness or coarse soil texture. So where the chaffy

grasses are part of the seed mix, broadcasting onto a prepared seedbed is sometimes a

necessity. Under these conditions, a second pass over the site with a cultipacker (with tines

raised) or a bulldozer (tracking) must be used to incorporate the seed into the soil. Hydroseeding

without tracking or cultipacking is unacceptable. Mixing chaffy seed with dry vermiculite or oat

seed will sometimes allow for flow through fertilizer spreaders, but this takes some experience

with particular machines to make it work.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

224

Apply mulch if needed. Acceptable amounts of mulch (0.5-1.0 ton ac-1) can vary based upon the

planting method to be used, but heavy mulching (2 ton ac-1.) rates are unacceptable because this

will hinder soil warming and light penetration to the developing seedlings.

Planting Dates

The ideal planting dates for seeding warm season grasses range from April 15 in the Mid-Atlantic

States to May 15 in northern New England. This roughly approximates corn planting season. Late

plantings increase the risk of frost heave on moderately well drained soils, because the seedlings

will not be as large as they would have been with a longer growing season. Late plantings also

increase the risk of hitting a dry period, and further delaying germination. However, delaying

planting to the end of corn planting season is justified if final weed control is required. Where

weed control has been very effective the year prior to planting, and/or droughty soils are present,

an early planting (one to three weeks prior to corn planting) is possible.

If a cover crop is needed over the winter, plant oats in late August or early September. The oats

will winterkill, thus not requiring herbicide kill in the spring, unless there are other grasses or

weeds germinating at that time.

Seeding Rates

Warm season grass seed is sold, and planted, based upon pure live seed pounds (PLS lb.). This

means that the gross weight of seed is increased to compensate for the inert material and dead

seed in the given seed lot. Buying mixtures of seed is not recommended, rather buy the seed

needed and make the mix just prior to planting. This allows for better quality control, and for

greater flexibility in using planting equipment. For instance, a seed like switchgrass which “flow”

can be planted out of a small seed box on a conventional drill. Smooth, flowable seeds tend to

settle out of a mix with the chaffy seeds as the drill bounces across the field.

Typical Grass Seeding Rates

(Use high range if broadcast or hydroseeding)

Core Mix:

Switchgrass or Coastal panicgrass; 2-5 PLS lbs ac-1

Big bluestem; 3-7 PLS lbs ac-1

Little bluestem; 4-6 PLS lbs ac-1

Indiangrass; 3-7 PLS lbs ac-1

Sideoats grama; 1-2 PLS lbs ac-1

Deertongue; 5-8 PLS lbs ac-1

For sites where less than 15% fines is present (sands, loamy sands, course

stands)

Add 1 PLS lbs ac-1 of sand lovegrass or 2 PLS lbs ac-1 of sand bluegrass

Optional additions to core seed mix if quick cover is needed for erosion control

Nurse grasses for quick cover:

Oats [Avena sativa L.] – 30 lbs ac-1 or

Annual ryegrass [Lolium multiflorum Lam.] -10 lbs ac-1
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Plus: companion grasses for initial and short-term cover

Redtop [Agrostis gigantea Roth] -1 lbs ac-1 or

Canada wildrye [Elymus canadensis L.] – 5 lbs ac-1 or

Fine fescue [Festuca spp.] - 15 lbs ac-1

Fine fescues include: hard fescue [Festuca brevipila R. Tracy ], Chewing’s fescue [Festuca rubra

var. commutata Gaudin], and sheep fescue [Festuca ovina L.]

Choose these companion (cool season) grasses based on availability, price and seeding

objectives. Redtop is acid tolerant and will withstand short periods of drought. Persistence is

much longer on wetter, poorly drained sites, however these sites are poor candidates for warm

season grasses. Canada wildrye has fair drought tolerance, but good salt tolerance. The fine

fescues will persist for many years under droughty, acid, and sterile soil conditions.

Adding the following legumes improves soil conditioning and habitat quality: select one or two)

Partridge pea [Chamaecrista fasciculata (Michx.) Greene] 4

Round-headed bush clover [Lespedeza capitata Michx.] 2

Wild indigo [Baptisia tinctoria (L.) R. Br.] 2

Recommended warm season grass cultivars for the northeast

GRASS SPECIES CULTIVAR(S)

Big bluestem Niagara, Kaw

Coastal panicgrass Atlantic

Deertongue Tioga

Indiangrass Rumsey, Osage, NE-54

Little bluestem Aldous, Camper, Blaze

Sand bluestem Goldstrike

[Andropogon hallii Hack.]

Sand lovegrass Bend, Nebraska 27

[Eragrostis trichodes (Nutt.) A.W. Wood]

Sideoats grama El Reno, Trailway

Switchgrass Blackwell (critical sites)

Cave-in-Rock (forage-north)

Carthage (forage-south)

Shelter (wildlife)

Managing the Establishing Stand

Warm season grasses are slower to germinate than cool season grasses, often taking 14-21

days before the seedlings can be seen. To determine what is coming up gently pass your hand

just over the soil surface and “feel” the emerging leaves, then dig up some seedlings to find and

identify the seed coats.

Unfortunately, weeds do not have low seedling vigor. The best treatment, when weeds begin to

shade the grass seedlings, is to clip the weeds just above the grass leaves with a sickle-bar

mower. Cut off as little grass leaf surface as possible although a leaf tip here and there is no

problem. Two to three clippings are almost always needed during the first growing season,

sometimes more. A rotary mower can be used as long as it can be elevated high enough, but it

tends to leave clippings in wads and windrows rather than thinly and evenly deposited over the

field.
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Dry weather after the seedlings are 3-4 inches tall is not a problem and, in fact, will help the warm

season grass by putting the brakes on the cool season grass seedlings that are sure to be

growing along with the plants desired. Therefore, irrigation is not warranted.

Fertilizer applications are recommended only if the area is essentially weed free in mid-July to

early August. Apply 30-40 pounds per acre of nitrogen to give the warm season grasses a boost,

but do not apply any after August 1 in the northern states or August 20 in the southern part of the

region.

When broad-leaved weeds are a problem, Banvel and 2,4-D are the herbicides of choice. These

can be used once the planted grasses are six inches tall with at least four leaves. All herbicides

must be used following label requirements.

Second Year Management

There may be an opportunity to control cool season grasses by spot treatment during the spring.

If sufficient growth occurs on the cool season grasses before any green growth appears on the

warm season grasses, judicious use of Roundup is possible.

Annual weeds will be crowded by the developing stand of warm season grasses and are rarely a

factor in stands with good density after year one.

For forage plantings, apply 60 lb. ac-1 of nitrogen after the grass has about six inches of growth.

Forage harvests, as hay or pasture, should begin as the stems begin to elongate (early boot

stage), and end six weeks before expected frost. Grazing should follow an intensive rotational

system. Harvest should allow at least six inches height to remain. Consult other references for

detailed harvest strategies.

Case Studies

New York/Northern New England

1. Franklin Co, NY (extreme northern NY), Plant Hardiness Zone 4. Gravel pit planting in 1975

comparing cool season and warm season grass varieties for long term droughty site persistence.

Cool season grasses were ineffective for erosion control and wildlife habitat. Warm season

grasses provided good cover and microsites for native woody vegetation establishment. Plantings

were part of a 10-site 6-state test which was reported in the Journal of Soil and Water

Conservation, Sept-Oct, 1987. These plots served as the basis for matching plant species

selection to soils based on percent fines passing #200 mesh sieve.

2. Gravel pit near Montpelier, VT, Plant Hardiness Zone 4. Planted in 1985 using warm-season

grass mix including ‘Niagara’ big bluestem, ‘Blackwell’ switchgrass, ‘Osage’ Indiangrass, and

‘Aldous’ little bluestem. This site was used as a demonstration of tracking in the seed with a

bulldozer. This planting method has been found repeatedly to be superior on steep slopes where

the use of a seed drill is impossible. The tracking technique following broadcasting (by hand,

mechanically, or hydroseeder) results in excellent germination in the cleat tracks. The difference

is typically dozens of seedlings per square foot vs. 0-2 seedlings per square foot where only

surface application is done.

3. Soil bioengineering planting in November 1988, near Gaysville, VT on a steep, dry slope.

‘Cape’ American beachgrass [Ammophila breviligulata Fernald] planted between contour lines of

‘Streamco’ purpleosier willow [Salix purpurea L.] wattles. Cape performed well for a few years

until the willows eventually dominated. This combination stabilized the slope by creating a

favorable microclimate for seed recruitment from the adjacent native trees and.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

227

4. Soil bioengineering, tidal stream, Wells, ME, Plant Hardiness Zone 5. Emergency Watershed

Protection planting in June 1993 following severe spring flooding. Bank erosion within 8 ft from

house foundations. Combination planting of ‘Streamco’ purpleosier willow, ‘Bankers’ dwarf willow

[Salix x cottetii Jos. Kern], and ‘Cape’ American beachgrass were planted. Cape provided initial

stabilization then was crowded out by willows. Homeowners expectations were exceeded by the

results of the planting which were preferable to rip-rap to the top of the bank.

5. Warm season grass cover for landfill reclamation at Roxbury and Williston VT, and Cortland,

NY, using mixtures of ‘Shelter’ switchgrass, ‘Niagara’ big bluestem, ‘Atlantic’ coastal panicgrass,

‘Bend’ sand lovegrass, and ‘Osage’ or ‘Rumsey’ Indiangrass. These sites have soils with low

percent of fines, droughty cap materials, especially in eastern NY and New England. The major

obstacle to using warm season mix was the relatively slow establishment and the resulting

possibility of erosion during the first summer. ‘Atlantic’ and ‘Bend’ provide improved establishment

during this process, then they are dominated by the other species over time. Due to winter injury,

‘Atlantic’ is only reliable for the first 2 years in NY and northern New England. Other landfill sites

such as Fresh Kills on Staten Island and Pelham Bay in the Bronx are now using this approach to

provide long-term, low maintenance, high value wildlife cover.

6. Warm season grass seeding at the East Corinth landfill in eastern Vermont. The native grass

seed was tracked in with a dozer. Seeding was a success, but engineers insisted that the site had

to be mowed. The cover struggled under mowing but has become well established since mowing

was abandoned as a maintenance strategy.

7. The Elizabeth copper mine tailings site in central Vermont. The site was bare and highly

erosive for 40 years with no native plant establishment except for broadleaved cattail [Typha

latifolia L.] in a wet spot. Plantings of warm season grass plots in 1988 demonstrated the ability of

the major species to tolerate the heavy metal concentrations and low pH at the site. A light lime

(1000 lbs ac-1) and fertilizer application (40 lbs ac-1) was made at planting and tracked in with the

seed. No soil was applied to the site.

8. A titanium and iron mine in Tahawas, NY (eastern Adirondacks) Zone 4, 1500 ft elevation.

Warm season grass mix, 1000 lbs. of lime and 80 lbs. of N-P-K were applied per acre, then

tracked in with a dozer.

9. Sand bluestem is not native to the Northeast. Like sand lovegrass it is very useful in mixes

destined for use on droughty, low-fines sites. ‘Goldstrike’ sand bluestem from Nebraska is

performing well after 10 years at the Swanton Airport in extreme northern Vermont, a few miles

from Quebec Province (plant hardiness zone 3).

Southern New England/Mid-Atlantic

1. Watershed Protection Project in Berkshire Mountains, MA (elevation 1800’) Indiangrass, big

bluestem, and little bluestem were seeded in November 1997 along with cool season companion

grasses, redtop and Canada wildrye. Light mulch was applied after seeding. The project site was

fertilized in the early summer with a liquid fertilizer. By late summer 1998, seedlings of big and

little bluestem were present on the site along with a good cover of redtop and scattered stands of

Canada wildrye. After the second growing season (summer 1999), seedlings of all the native

grasses seeded were evident throughout the project area with some individuals producing

seedheads. Only very localized rill erosion had occurred during the native grass establishment

period.

2. Hart-Miller Island, MD. This is a dredge containment facility for material dredged to keep the

Baltimore Harbor shipping channel open. The containment dike is composed of unconsolidated

coarse-textured sands and gravels. The dikes have a 1:1 slope (45 degree) slope which preludes

the use of any seedbed preparation or seed drilling equipment on the slope. The grass mix

composed of ‘Atlantic’ coastal panicgrass, ‘Blackwell’ switchgrass, weeping lovegrass [Eragrostis
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228

curvula (Schrad.) Nees], partridge pea, and ‘Lathco’ flat pea [Lathyrus sylvestus L.] was

hydroseeded onto the slope. A chain was then dragged across the slope to improve seed to soil

contact. Also, a liquid fertilizer was added to provide some nutrients to the sterile soil. A fully

established stand was present after two growing seasons. Seven years after seeding the warm

season grasses are persisting well.

3. Hopatcong Civic Center northern New Jersey. Warm season grasses were seeded on a

barren, gravelly to cobbly outwash slope. Prior attempts to establish cool season grasses on the

site were unsuccessful. The native seeds were broadcast and tracked in with a bulldozer. A full

stand of native grasses developed within two growing seasons and is persisting five years after

seeding.

4. Coastal strip (NJ, DE, MD). ‘Atlantic’ coastal panicgrass was successfully seeded in back

dune areas between rows of beachgrass. Seeding has been done with a simple garden seeder

(Planter Jr.) set at a 1 1/2”-2” depth. Seedlings emerging the first year generally ranged from 2”-8”

in height. Within three growing seasons, the coastal panicgrass crowded out American

beachgrass, a pioneer plant, and dominated the site with the long-term cover.

Summary

Warm season grasses have become an important tool for conservation plantings in the

Northeast. The benefits which these grasses bring to the planting site include long life, tolerance

to acid and low fertility conditions, compatibility with forbs, superior root production, soil

improvement, and exceptional wildlife habitat. Natural resource agencies should be finding ways

to incorporate the use of these grasses in their programs, but are cautioned to utilize effective site

selection and planting procedure criteria.

References

Dickerson, J.A., B. Wark, D. Burgdorf, R. Maher, A. Bush, W. Poole, and C. Miller. 1997.

Vegetating with Native Grasses in Eastern North America. USDA-Natural Resources

Conservation Service and Ducks Unlimited Canada. 63p.

Gaffney, F.B. and J.A. Dickerson. 1987. Species Selection for Revegetating Sand and Gravel

Mines in the Northeast. Journal of Soil and Water Conservation. 42:358-361.

Vickery, P.D. and P.W. Dunwiddie. 1997. Grasslands of Northeastern North America.

Massachusetts Audubon Society, Lincoln, MA. 297p.

Weaver, J.E. 1968. Prairie Plants and Their Environment. University of Nebraska Press, Lincoln,

NE. 276p.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

229

Surface Mining Reclamation Revegetation Guide

D. P. Morris1

Abstract

Preparation for reclaiming a surface mine literally begins before ground disturbance and mineral

recovery at a proposed mine, through the process of initially developing an environmentally

sound mined land use plan. Most if not all reclamation objectives involve re-establishing a good

vegetative cover on final land grades. The intention of this guide is to provide and encourage

more ecologically diverse reclamation alternatives when considering the revegetation phases of

mine closer. Plant material choices are limited to species, which will tolerate site specific growing

mediums created at the time of final land grading. These choices have typically been further

limited because many native species were not being propagated and available commercially. A

wide variety of native and non-native species are now being cultured and available for use over a

broad spectrum of reclaimed site conditions. This revegetation guide will provide assistance to

landowners, miners, professional consultants and governmental staff during both the planning

and development stages of reclamation so that more effective, alternative and economically

feasible decisions are utilized. These goals are achieved by first advocating alternative

revegetation methods and second by simplifying the planning and implementation processes of

the multidisciplinary issues involved. This guide provides a brief description of the optimal

planting conditions required by different species so that accurate preplanting site conditioning is

performed. Chapter 1 introduces concepts of reclamation and long-range land use perspectives.

Chapter 2 defines significant preplanting, planting, and erosion control considerations, which

accommodate revegetation success. Site characteristics required by the different vegetation

groups, trees, shrubs, forbs and grasses are explained within Chapter 3, and are intended to be

assessed during the plant materials selection stage of a reclamation project. Chapter 4 outlines

maintenance schedules to follow after the initial planting and recommends management practices

used to overcome undesirable conditions. Finally, a list of commercial growers and nurseries

offering plant materials and seed sources are referenced for the benefit of the user.

 

1

 Mined Land Reclamation Specialist, New York State Department of Environmental

Conservation, Albany 12233
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230

Grasses and Other Native Plants in Designed and Managed Landscapes

Darrel Morrison1

Abstract

Since the 1970’s, there has been a slow, but steadily growing, interest in the use of native plants

in designed-and-managed landscapes. This is in response to the recognition that many

traditionally designed landscapes are unnecessarily consumptive of resources and overly reliant

on chemical pesticides. One step toward more sustainable landscapes, economically and

ecologically, is the use of native plants – or better yet, communities of naturally associated

species – in designed-and-managed landscapes.

This approach is, in a way, a return to one that was practiced in this country for the early decades

of this century by such landscape architects as Jens Jensen, Frank Waugh, and Elsa Rehmann.

Rehmann, with her colleague Edith Roberts, a plant ecologist, published a book in 1929,

American Plants for American Gardens, in which they advanced the idea of using natural

communities as models for designed landscapes.

Recent work, which takes this approach, will be presented with an emphasis on projects in the

Eastern United States in which native grasses are incorporated. These projects, it is hoped, will

illustrate not only an ecologically sound approach, but also the potential aesthetic richness of

landscapes based on natural communities of the region in which they occur.

 

1

 FASLA, Professor School of Environmental Design, University of Georgia, Athens, GA
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

231

Carbon Stored in Soils under Eastern Grasslands

Lloyd B. Owens and Daniel L. Hothem1

Organic matter has long been considered important in agricultural soils. But with global change

issues and the possible role of CO2 in those changes, it is important to evaluate the potential

practices to mitigate CO2 emissions through carbon storage. Many cropping practices need to be

studied, including grasslands.

At the North Appalachian Experimental Watershed (NAEW) near Coshocton, OH different

grazing/grassland management practices have been studied for over 20 years. Soil samples

from these systems were taken and archived over much of the life of these studies. The

objectives of the work presented in this paper were to use soil samples from four pasture

management systems to (a) measure total carbon concentrations in the soil profile and to (b)

assess the amount of total carbon in the soil profile. The results presented here are only a

preliminary assessment of the soil data.

Methods

One management system (System I) was an unimproved pasture system (Owens, et al. 1996). It

is a 28 ha (70 ac) watershed which was ungrazed from 1972-74; summer grazed without rotation

by a beef cow/calf herd from 1975-79; grazed the entire year with hay brought in during the winter

during 1980-87; and grazed the entire year with the stream and riparian woods fenced from 1988-

99. Slopes range from 2 to 35% with an approximate average of 17%. Soils are residual silt

loams C well drained (typic Hapludults and typic Dystrochrepts) above a clay outcrop; moderately

well drained (aquultic and aquic Hapludults) below the outcrop. Vegetation included a thin stand

of perennial grasses (Kentucky bluegrass [Poa pratensis L.]; orchardgrass [Dactylis glomerata

L.]; red top [Agrostis gigantea Roth]); legumes (white clover [Trifolium repens L.]; red clover

[Trifolium pratense L.]; alsike [Trifolium hybridum L.]; black medic, [Medicago lupulina L.]); and

pasture weeds, e.g. dandelion [Taraxacum officinale Weber ex F. H. Wigg. Group], plantain

[Plantago sp.], and yarrow [Achillea millefolium L.].

System II was a medium fertility, rotational pasture system (Owens, et al. 1992). It is a 17 ha (42

ac) area divided into four paddocks that were rotationally grazed by a beef cow/calf herd with one

paddock being used for winter feeding (hay was brought in) and annually received 56 kg N ha-1

from 1974-78. During 1979-89, 168 kg N ha-1 was annually applied in 3 split applications to the

same grazing scheme. From 1990-99, no N fertilizer was applied; two paddocks were grazed

and hay was made on two paddocks; and there was no winter feeding on these paddocks.

Slopes range from 12 to 25% with an approximate average of 20%. Soils are well-drained

residual silt loams (typic Dystochrepts and Hapludults). Vegetation was predominantly

orchardgrass and Kentucky bluegrass.

System III was a high fertility, rotational pasture system (Owens, et al. 1998). It is a 14 ha (34 ac)

area divided into four paddocks that were rotationally grazed by a beef cow/calf herd in the

summer from 1975-79. Annually, 224 kg N ha-1 was applied in 3 equal applications in the spring

and summer. In 1980, legumes were sown into the grass and no N fertilizer was applied. The

same grazing scheme was used through 1998. Slopes range from 2 to 18% with an approximate

average of 12%. Soils are well-drained, residual silt loams (typic Hapludults) above a clay

outcrop and moderately well drained (aquic Hapludalfs) below the clay outcrop. Vegetation was

predominantly orchardgrass and then reseeded with orchardgrass and alfalfa [Medicago sativa

L.].

 

1

USDA-ARS, P.O. Box 488, Coshocton, OH 43812
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

232

System IV was a high fertility area (10 ha, 25 ac) where hay was made in four paddocks and

stored in them (Owens, et al. 1998). A beef cow/calf herd was rotated through the paddocks to

eat the fall regrowth and to use the stored hay. From 1975-79, 224 kg N/ha was applied annually

in 3 split applications; from 1980-98, legumes were sown into the grass and no N fertilizer was

applied. Slopes range from 6 to 25% with an approximate average of 15%. Soils are welldrained residual silt loams (typic Dystrochrepts and Hapludults). Vegetation was predominantly

tall fescue [Festuca arundinacea Schreb.] and was then reseeded with tall fescue and alfalfa.

Soil samples were taken from these pasture systems during many of the years since 1975, and

were stored. Several of the samples were taken to a 150-cm depth. Total carbon was

determined on selected soil samples over the various study periods. Results are preliminary, and

the soil data are presented without any statistical analyses.

Results

Total carbon concentrations were observed as high as 5.1% in the 0-2.5 cm layer of System II

(2.3% for the 0-15 cm layer) in the 1990 samples. Carbon concentrations dropped rapidly with

soil depth. With some exceptions in the 15-30 cm layers of Systems III and IV and in the riparian

woods of System I (Table 1), total carbon levels were <0.5% below 15 cm. In Texas, Potter et al.

(1999) measured soil organic carbon in soils under agricultural practices, grass, and prairie C

listed in increasing order of soil carbon. Although the total carbon decreased much more rapidly

with depth in the Ohio soils, the carbon levels in the 0-15 cm levels were similar between this

study and the levels reported for the grass soil in Texas. The total carbon concentrations in the

0-15 cm levels in all four systems were greater in 1998 samples than in the 1975 samples (Table

1). However, it is doubtful that the differences are significant.

Total carbon amounts (soil bulk density was included in the calculations) were also greatest in the

upper soil layers, 30-37 Mg ha-1 in the 0-15 cm layer of most of the systems (Table 2). System

III had the greatest amounts of carbon in the 0-60 cm layers (63-76 Mg ha-1) of the four systems

because of more carbon being present in the 15-30 cm layer than the other systems.

In addition to the pasture studies at the NAEW, research was conducted on similar soil types

using a no-till corn/soybean rotation with a rye winter cover crop following the soybeans. Carbon

levels in this agricultural use were lower than fertilized pastures, 1.0-1.6% in the 0-15 cm layer

compared with 1.2-2.4% under pastures (Table 1). Similarly, total carbon amounts were lower in

the no-till practice (31-36 Mg ha-1) than under fertilized pastures (42-56 Mg ha-1) (Table 2). Even

the total soil carbon concentrations and amounts in the unfertilized, unimproved pasture were

comparable or slightly higher than the corresponding values for the no-till corn/soybean-rye

system.

Carbon to nitrogen ratios tended to be higher in the upper soil layers of the pastures with a 10 to

12 ratio in the soil layers in the top 30-cm. Between 30 and 60 cm, the C:N ratios ranged from 6

to 11. The highest C:N ratios observed were in the riparian woods where they ranged from 12 to

17 in the top 60-cm of the soil profile. With the exception of the first year of the corn/soybean-rye

rotation (the previous year was grass), C:N ratios in the no-till areas was similar to the above

values for pasture soils.

Summary

Total carbon concentrations in pasture systems on well or moderately-well drained, residual silt

loams were found to be as high as 2.5% in the 0-15 cm layer (5.0% in the 0-2.5 cm layer) and as

high as 3.0% in the 0-15 cm layer of riparian woods. Total amounts of carbon in pasture soils

ranged from 50-75 Mg ha-1 for the 0-60 cm soil depth and tended to be slightly higher with higher

fertility. Pastures had greater carbon concentrations and carbon amounts than no-till

corn/soybeans-rye on similar soils. Very little variability of C:N ratios was observed among the

systems studied. Exceptions were higher C:N ratios in riparian woods (12-17) and in the first
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

233

year of no-till corn/soybeans-rye following grass (13-16). Preliminary data analyses have not

shown major trends of carbon concentrations or carbon amounts over time within a pasture

system.

References

Owens, L.B., W.M. Edwards, and R.W. Van Keuren. 1992. Nitrate levels in shallow groundwater

under pastures receiving ammonium nitrate or slow-release nitrogen fertilizer. J. Environ. Qual.

21:607-613.

Owens, L.B., W.M. Edwards, and R.W. Van Keuren. 1996. Sediment losses from a pastured

watershed before and after stream fencing. J. Soil and Water Cons. 51:90-94.

Owens, L.B., R.W. Van Keuren, and W.M. Edwards. 1998. Budgets of non-nitrogen nutrients in

a high fertility pasture system. Agri., Ecosystem & Environ. 70:7-18.

Potter, K.N., H.A. Torbert, H.B. Johnson, and C.R. Tischler. 1999. Carbon storage after longterm grass establishment on degraded soils. Soil Sci.164:718-725.

Table 1. Average Total Carbon concentration (%C) in various systems at three different

sampling time

Depth (cm) 1975 1985 1998

I. Unimproved Pasture

 0-15 1.3 1.3 1.9

15-30 0.4 0.5 0.5

30-45 0.2 0.2

45-60 0.2 0.3

II. Riparian Woods

 0-15 3.0 2.8

15-30 0.8 1.1

30-45 0.5

45-60 0.3

III. Medium Fertility, Rotational Pasture

 0-15 2.0 2.3 2.4

15-30 0.6 0.4 0.5

30-45 0.3 0.2 0.2

45-60 0.2 0.2 0.2

IV. High Fertility, Rotational Pasture – Summer grazing

 0-15 1.6 2.0 2.2

15-30 1.0 0.9 0.9

30-45 0.3 0.4

45-60 0.3 0.5

V. High Fertility, Rotational Pasture – Winter-feeding/grazing

 0-15 1.2 1.7 1.8

15-30 0.6 0.9 0.8

30-45 0.2 0.4

45-60 0.3 0.5

1984 1990 1995

No-till – Corn/Soybean-rye

 0-15 1.6 1.0 1.2

15-30 0.5 0.5 0.5
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234

Table 2. Average Total Carbon amounts (Mg ha-1) in the top soil profile layers for various

systems at three different sampling times. Totals are in bold italics.

Depth (cm) 1975 1985 1998

I. Unimproved Pasture

 0-15 24.4 30.4 30.2

15-30 10.5 11.4 10.1

30-45 4.9 5.5

45-60 5.0 6.8

Total 44.8 52.6

II. Riparian Woods

 0-15 54.7 32.4

15-30 16.6 16.4

30-45 10.3

45-60 6.9

Total 66.0

III. Medium Fertility, Rotational Pasture

 0-15 34.5 34.2 34.4

15-30 10.8 9.9 11.7

30-45 6.3 7.7 5.2

45-60 5.7 4.7 4.5

Total 57.3 56.5 55.8

IV. High Fertility, Rotational Pasture – Summer grazing

 0-15 29.4 37.7 36.0

15-30 20.0 17.8 18.6

30-45 7.2 9.3

45-60 6.6 12.0

Total 63.2 75.9

V. High Fertility, Rotational Pasture – Winter-feeding/grazing

 0-15 29.4 30.9 30.2

15-30 14.9 11.6 11.4

30-45 4.7 5.8

45-60 2.8 3.8

Total 51.8 51.2

1984 1990 1995

No-till – Corn/Soybean-rye

 0-15 29.6 18.9 24.9

15-30 9.4 12.3 11.1
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235

Rehabilitation of Sandy Soils with Native Species in the

Northeast United States

A. J. Palazzo, T. Cary1, and T. Lent2

Abstract

Sandy soils in the northeastern United States are difficult to rehabilitate due to their low moisture

and nutrient-holding capacities, the short growing season, and the drying effects of winds. The

added stress of intensive land use makes military lands even harder to rehabilitate. Sandy-soil

rehabilitation is a problem at Fort Drum, New York; Fort McCoy, Wisconsin; the Canadian Forces

Base in Petawawa, Ontario; and numerous US Army Corps of Engineer sites with dam

embankments, mine-tailing sites, borrow pits, and roadsides.

A major problem in seeding native plants is their slow establishment. We explored methods of

providing a suitable plant cover that will establish rapidly and provide a native plant stand over

time. We looked at soil compaction, root growth of native and introduced plants during

establishment, and field studies of seeding both types of plants together.

We found soil compaction, which increases water-holding capacity, to be important in both plant

establishment and persistence. In field studies, we applied liquid cow manure at varying rates to

modify surface soil temperature and retain moisture and found that all grass species grew better

where the manure was applied. For short-and long-term cover, we tested a mixture of

switchgrass [Panicum virgatum L.] (native), hard fescue [Festuca brevipila R. Tracey]

(introduced), and weeping lovegrass [Eragrostis curvula (Schrad.) Nees] (introduced), which was

sown with a no-till seeder into the manure cover. The weeping lovegrass provided greater than

80% cover in the first season. Highly susceptible to winterkill, weeping lovegrass shows promise

as a nurse crop for slow-growing native species and for short-term rehabilitation of intensively

used sites. After the initial season, the switchgrass and hard fescue grew through the dead

weeping lovegrass and began to dominate the site. Previous studies have shown that hard

fescue will persist for about five years; after that, native plants should dominate the site.

 

1

 Research Agronomist and Physical Science Technician, USACRREL, Hanover, NH and 2Land

Manager, Fort Drum, NY
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

236

Managing Switchgrass as Biofuels Feedstock

D.J. Parrish, D.D. Wolf, P.R. Peterson, and W.L. Daniels1

Abstract

Switchgrass [Panicum virgatum L.], a native perennial, is being studied as a model species for a

system in which herbaceous plants would be grown for conversion into liquid fuels or for direct

combustion. We are in the eighth year of an eight-location, five-state (KY, NC, TN, VA, WV) trial

with six varieties or lines of switchgrass. The plants are receiving varying rates of N and two

different cutting managements—once or twice per year. The first harvest of the two-cut

management comes in late June, and the fall harvest with either one- or two-cut management

comes near the end of October. These studies have focused on biomass yields and nutrients

removed in the biomass. Parallel studies have looked at C and N fluxes within the biomass. The

findings to date indicate that switchgrass productivity varies greatly with location and variety and

to a lesser degree with N and cutting management. The lowland varieties used (‘Alamo’ and

‘Kanlow’ and two breeder’s lines) showed little or no yield increase with two cuttings. The two

upland types (‘Indian” and ‘Shelter’) yielded 20 to 30% more when they were cut twice. With that

boost in yield, they approached the lowland types in productivity. Parallel studies detected

standing biomass declines of about 10% between August and late October. During that interval,

tissue N concentrations decline in the aboveground portions of the plants and increase in

belowground portions. It appears that the plants translocate significant amounts of biomass

below ground at the end of the growing season. This would appear to be a strategy that

conserves N and promotes growth in the following season. Cutting twice (with one cut taken in

June, when the plants are relatively rich in N) appears to deplete the plants’ N reserves. A

response to N fertilization was evident primarily when the plots were harvested twice per year,

i.e., there was no yield benefit of adding 100 kg N/ha to plots that were harvested only after the

end of the growing season. The parallel studies also suggest that switchgrass has the potential

to sequester significant amounts of C within its roots and the soil. This work was supported in

part by funding from Oak Ridge National Laboratory, managed for the U.S. Department of Energy

by Lockheed Martin Energy Research Corporation.

See: Parrish, D.J., D. Wolf, P.R. Peterson, and W.L. Daniels. 2000. Successful Establishment

and Management of Switchgrass. Proceedings of the Second Eastern Native Grass Symposium

(This volume)

 

1

 Department of Crop and Soil Environmental Sciences, Virginia Tech, Blacksburg, VA 24061-

0404
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

237

Successful Establishment and Management of Switchgrass

D.J. Parrish, D.D. Wolf, P.R. Peterson, and W.L. Daniels1

Abstract

Switchgrass [Panicum virgatum L.], a native perennial, has a reputation for being difficult to

establish. Using no-till planting methods, we have found that we can get excellent stands and

significant biomass production from switchgrass even in the establishment year. The keys to

success include the interconnected factors of overcoming seed dormancy, optimizing planting

date, and providing pest control. Seeds of switchgrass are highly dormant when first harvested;

as few as 5% of the seeds in commercially obtained seedlots may be germinable, even though

their seed tag can show 90+

% "pure live seed". This dormancy may be largely overcome by

stratification -- exposing wet seeds to 5 to 10°

C for 2 to 4 weeks. While it works quite well for

breaking the dormancy, there are issues with scaling up stratification for large quantities of seeds

and with a tendency for stratified seeds to regain dormancy when they are dried. Other

dormancy-breaking techniques may be more commercially useful. Weeds can also be a serious

threat to plantings. Good pre-planting weed control and planting (using non-dormant seeds!)

after the soil is fully warmed (mid- to late-June in our area) are essential for success with no-till

plantings. The late planting date allows the switchgrass seedlings to make such rapid growth that

competition from most co-emerging weeds is minimal. We frequently find that insect control is

crucial in the vigor of first-year growth. Although no products are currently labeled for this use,

our experimental results suggest that including an insecticide to control flea beetle can have a

dramatic effect on biomass production during the establishment year. There may be less

difference between insecticide-treated and non-treated plots in years after planting, as long as

other stress factors (such as germinable seed, drought, and weed pressure) are not experienced.

Introduction

Switchgrass is a tall-growing, warm-season, perennial grass that is native to much of the United

States including Virginia. Switchgrass (SG) was widespread in open areas before European

settlement. However, after European settlement livestock that were free roaming grazed the new

switchgrass growth in the spring before the plants were leafy enough to withstand defoliation

which weakened the stands and eventually led to their demise. Switchgrass and other warmseason grasses were replaced by introduced cool-season grasses such as bluegrass, tall fescue,

and orchardgrass. These cool-season grasses begin growth much earlier in the spring and can

tolerate early season grazing. As a result, the native warm-season grasses such as switchgrass

were displaced and can now be found growing primarily in abandoned sites such as old

cemeteries or roadsides.

In Virginia, switchgrass breaks winter dormancy in late April and can provide some grazing in late

May, but makes most of its growth in June, July, and August. Since it is a tall-growing grass, the

management must differ from that used for cool-season grasses. Switchgrass provides excellent

erosion control when used as filter strips, grass hedges, or cover such as on river levee banks. It

is also beneficial for wildlife. The upright growth provides wildlife some overhead cover for

protection, quality nesting sites, and free movement which facilitates food searching. In

established stands, there is little disease problem and essentially no insect pests. Since it is a

perennial, when properly managed, switchgrass should never need to be replanted.

 

1

 Department of Crop and Soil Environmental Sciences, Virginia Tech, Blacksburg, VA 24061-

0404. This work was supported in part by funding from Oak Ridge National Laboratory, managed

for the U.S. Department of Energy by Lockheed Martin Energy Research Corporation.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

238

Planting Year Management Strategies

Selecting the field: Switchgrass does well on a wide variety of soil types. Unlike cool-season

grasses, it is drought-tolerant and produces well on shallow, rocky soils. It is also as tolerant of

wet areas as reed canarygrass. Because no-till seeding is ideal for switchgrass, steep slopes can

be planted without having to deal with such tillage problems as soil erosion and rock exposure. It

is important when planting steep slopes to select a drill or make the necessary adjustments so

that the disk opener follows the leading coulter. A drill with a rigid, fixed-position coulter-disk

opener assembly will not caster downhill.

Soil pH should be 5.0 or above. If soil tests indicate medium or higher P2O5 and K 2O, no fertilizer

is needed at planting. No N should be applied at planting; however, if a good weed-free stand is

obtained by early August, 33 to 44 kg of N ha-1 (30 to 40 lb. N per acre) can be applied on fields

where growth is slow and plants are a pale green color from N deficiency. Switchgrass is a good

scavenger of nutrients; therefore, N is seldom needed in the establishment year.

Previous crop: Weeds can be a major obstacle for switchgrass establishment especially

summer annuals such as barnyard grass, crabgrass, foxtail, and panic grass. Planning ahead can

reduce these. One year before planting switchgrass, a smother crop such as dwarf pearl millet

can be planted, followed by a cereal grain in the winter. Since foxtail (German) millet is a one-cut

crop, dwarf pearl millet is preferred as a smother crop. It will grow longer and give several

grazings or two hay cuts. Cereal grain can be grazed or cut for hay by late April or mid May,

making it easier to control the regrowth of weeds before switchgrass planting.

Soybeans or corn can be used as a previous crop. If corn was harvested for grain, the stalks may

need to be raked and bailed or incorporated into the soil to eliminate excess trash. A cereal grain

could be planted after corn is removed for silage. One year prior to switchgrass planting, a field

could be plowed or chisel plowed, if needed, to bury excess trash, increase infiltration, or smooth

the land where it is too rough for operating machinery.

Minimize surface residue: As with no-till alfalfa and other small-seeded forages, switchgrass

cannot be planted into very much surface residue. Many perennial grasses in pastures or hay

fields accumulate too much trash, which prevents good seed-to-soil contact. The trash often is

pushed down in front of the coulter and seed is placed in the fold (hair pinning). About 50 % or

more bare surface is desirable before planting. Burning surface trash is ideal if it is dense enough

to carry a fire. When properly timed, the burn will kill small weeds and be equivalent to the use of

a contact herbicide. Local fire departments, soil conservation units, or forestry service personnel

may be sources of help in safe burning.

Previous sod crop: In a geographic area such as Virginia, graze the planting site as closely as

possible or make hay before May 1. If the area cannot be grazed or cut for hay then a herbicide

may be needed in early April to prevent excessive growth. About mid to late May when adequate

leaf area has developed on the vegetation, spray with glyphosate (Roundup). With low rate

technology, 7.5 l ha-1 (2 qt acre-1) will be adequate. Alternatively, paraquat (Gramoxone) at 0.9

5.49 (1 qt) can be used, if the weeds and grasses present are species that can be controlled with

this contact herbicide. About 4 to 6 weeks later or as close to the day of planting as possible,

spray again. Gramoxone at 0.5 l ha-1 should be sufficient for the second application. If persistent

weeds or perennial grasses are present, use an application of Roundup. As mentioned earlier,

excess trash can be a serious problem. Use of an herbicide followed by burning is an ideal

combination. If burning is planned, Roundup in mid April or Gramoxone in early May will cause

desiccation of vegetation so that fire in mid May will act as a herbicide. Then 3 to 4 weeks later

another application of an herbicide can be used immediately before planting.

Selecting a variety: Indian is the preferred variety in much of Eastern USA where grazing or hay

will be all or part of the intended usage. It is ready to graze in late May and has little growth in

September. Alamo and Kanlow are better suited to wildlife and soil conservation plantings. They
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

239

begin growth earlier in the spring and stay green later in the fall than Indian. Properly managed,

they are good for grazing and may fit best in some forage systems where some grazing is needed

in September. Due to their very stiff straw, they may be preferred for wildlife plantings and for

hedge rows.

Seed germination and quality: Planting seed with a high degree of germination is important in

obtaining a good stand. Switchgrass seed often has a high proportion of dormant seed when

harvested. This dormancy evolved so that the seed could survive in nature. Dormancy is broken

when seed is stored dry for 2 to 4 years in a warm place. Dormancy is also broken when exposed

to cold-wet conditions (stratification) such as will occur in nature when left on the ground during

the winter after falling from the plant in late summer. Adequate cold-wet conditions will occur

naturally in the field if planted in late winter to about May 1. However, when planted early enough

to be stratified in the soil, weed competition may be serious enough to crowd out small seedling

switchgrass.

Seed should always be purchased on a pure live seed basis (PLS). The seed tag will usually

indicate a very high germination, which has been obtained by official (ideal) conditions that

include stratification. The hard (or firm) seed are those that are viable but will not germinate after

stratification. When planting after the soil warms up, one cannot depend on using the official

germination test printed on the seed tag as a true indicator of what seed germination will be.

Instead, obtain, or conduct, a germination test without stratification. A "ragdoll" test, which a

producer can easily conduct, is adequate if the instructions below are followed. If germination,

without wet pre-chill, is less than 40 percent, one should plan to do a bulk stratification ("wet prechill") or use an increased seeding rate.

"Ragdoll" test for seed germination: Before planting, test your seed in a flower pot with soil or

in a "ragdoll." A "ragdoll" is a rolled tube of wet paper containing the seeds to be tested for

germination; it is placed in a jar or plastic bag and kept in a warm place for several days. Then

the seedlings are counted as they are removed, giving the percentage germination.

Properly used, the ragdoll test is of great value, but some suggestions will help obtain the best

results:

1. Use a firm paper towel such as a brown hand towel or its equivalent. The "soft," very

absorbent paper toweling often used in a kitchen makes poor ragdolls. It allows roots and

tops to penetrate the fiber, making seedlings difficult to remove for counting. If kitchen

towels must be used, be sure to squeeze all excess water from them to prevent seed

rotting. Too much water causes a lack of oxygen, and the roots of seedlings (radical) will

be more retarded than the top.

2. After the towel has been squeezed rather firmly, lay the wet toweling flat. Count out 100

seeds and place them on one half of the towel. Fold the towel in half and roll it into a

tube. Place the tube upright in a jar or plastic bag. This position causes roots to grow

down and shoots to grow up so that seedlings are more easily removed during counting.

The ragdoll should be kept in a warm place, preferably on top of a water heater or

refrigerator. A temperature of 30°

C (85°F) is best, but seeds will do fine at room

temperature.

3. Make the first count in about 4 days. Open the towel and count the seedlings as removed.

After another 3 to 4 days, make a second count. With 100 seeds, the number of

seedlings removed equals the percentage germination. If seeds were not counted

initially, count the remaining seeds and calculate percentage germination. Always save a

small amount of any seed planted so that, if the stand is poor, you can check germination

again to be sure the problem was not bad seed. If the seed won’t germinate in an ideal
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

240

environment like a "ragdoll," don’t expect much success when the seed is dealing with all

the hazards found in a field situation.

It is always a good idea to test the ragdoll procedure by placing a few seeds of millet or alfalfa

that will germinate wet. If these seeds germinate well, the ragdoll is working properly. If these

seedlings are stunted, then the ragdoll may be too wet.

Wet-chill to break dormancy: If germination in the ragdoll test is low (less than 40 %), and one

has a relatively small amount of seed to plant, seed should be wet-chilled to break the dormancy.

In nature this wet-chill, called stratification, occurs naturally during the winter. If the wet-chill

treatment is required, follow the procedure outlined below:

1. Put the seed in a cold place to be brought to a lower temperature (about 10o

C).

2. Soak the seed in cold water for about 24 hours in plastic-mesh feed sacks.

3. Remove the sacks from water and hang them in a cool place for about 24 hours to drip

dry.

4. Monitor the temperature inside the wet bag of seed, if possible, to be sure of safe

conditions. Place the outdoor sensor of an indoor/outdoor thermometer inside the bags.

These units are inexpensive and can be used later for other purposes.

5. Place the sacks in a refrigerator and keep chilled at about 100

C (500F) for 2 to 3 weeks.

Freezing the seed doesn’t harm it, but it does prevent the seed from breaking dormancy.

Take seed samples at 7-day intervals during the chilling process and test them to see

whether germination percentage has increased. Usually, it takes 21 days to break

dormancy adequately.

6. Remove seed from the refrigerator and dry it by placing it less than 8 cm deep on a dry

tarp with a fan blowing over it. Dry the seed until it flows freely. Plant the chill-treated

seed as soon as possible. If planting must be delayed, chill-treated seed will be safe if

stored in a dry place.

Seeding date (for a geographic area such as Virginia): Switchgrass germinates very slowly

when soil temperature is below 16°

C (60°F). If moist, non-dormant seed is maintained at 30°C

(85°

F) for 3 days, many of the seedlings will germinate and grow to a length of approximately 3

cm (1.2 inch) with a 3 cm long root. The planting time for switchgrass is much later than for corn

but similar to that for millet or sorghum-sudan. Plant from June 1 to 15 for conventionally

prepared seedbeds if soil moisture may be a concern. Plant no-till seedings between June 15 and

July 15, because soil moisture will be less of a problem. In situations where weeds are not a

problem, planting can be done 2 weeks earlier. Planting as late as possible will provide adequate

time for preplanting weed seed germination and control and a better chance of controlling annual

grassy weeds. Under favorable conditions, newly seeded switchgrass can be 25 to 50 cm (10 to

20 inches) tall and well established 8 weeks after planting. After a seedling develops basal tillers,

it should survive the winter.

Seeding rate and gauging establishment success: Consider using 10 kg of pure live seed

(germinable) per ha (9 lb. per acre) for conventional plantings. For no-till or drill seedings 7 kg per

ha (6.3 lb. per acre) should be adequate. The germination should be based on a test made after

stratification, if needed. Weight of bulk seed needed can be calculated [kg needed = kg ha-1 ÷

(germination x purity)] where germination and purity are expressed as decimal values. Planting

seed that may not germinate is neither logical nor economical. As stated above, if the seed will

not germinate in the ideal conditions of a ragdoll, it will not in a field environment. Stratification will

increase the chance of germination. Indian switchgrass, and some other up-land types, usually

have 500,000 seeds kg-1 (227,000 seeds per lb.). Alamo, and some other low-land types, may

have 900,000 seeds kg-1 (454,000 seeds per lb.). Seven kg ha-1 will have about 350 potential

seedlings m-2 (37 seedlings ft-2). This should give about 71 seeds per linear m of row (22 per

foot) if rows are 20 cm (8 inches) apart. [Drill calibration can be approximated using these

numbers of seeds per linear row lengths]. At the end of the planting season, if one has 50 or so

plants per m2

 (about 10 per square foot) constitutes an excellent stand. Don’t give up on a stand
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

241

that seems to be poorly established, especially for wildlife and soil conservation plantings. Even

stands with an average of 10 plants per m2

 can be adequate, since each plant can easily occupy

0.1 m2

 with two or three years of growth.

Seeding into a conventional seedbed: Field operations typically used for other small seeded

forages can be used to prepare a clean seedbed. Take care to insure that the soil is especially

firm at planting. If a pickup truck driving over the field leaves a noticeable wheel track depression,

then more packing may be needed. Conventional seeding may not be ideal, because tillage will

cause the soil to lose water in the warm, dry weather during mid June when these operations are

needed. Seed can be broadcast and then cultipacked. Seed placement in rows with a grain drill

that has a small seed attachment would be ideal. Seed should be placed no deeper than 7 to 12

mm (1/4 to 1/2 inch). Consider cultipacking after drill planting in order to obtain good seed-soil

contact. Weed problems may be greater than with no-till plantings since germinable weed seeds

will be brought to the soil surface during tillage.

No-till planting: No-till seeding methods conserve soil, require less time and fuel, and allow

rocks to remain below the soil surface. Proper procedures will reduce water run-off and

evaporation, which improves the water supply to the seedling. If herbicides are used to suppress

existing vegetation during the 6 to 8 weeks before planting, there should be adequate water for

rapid germination.

A standard grain drill with a box for small seed like clover can be used if there is minimal trash

and the soil is soft, such as when planting into a preceding soybean, corn, millet, or cereal grain

crop. A drag chain and packer wheel should follow each drill opener. If needed, a cultipacker

should be used to firm the soil. With no-till methods, one may be tempted to plant when the soil is

too wet and seed might be placed too deep. Ideally the soil surface should be rather dry. When

trash is dry and soil is firm, the disk or coulter can cut a clean seed slot without hair pinning. The

disk opener should displace some granular soil. Seed should be placed about 7 to 12 mm (1/4 to

1/2 inch) deep. Rainfall can wash soil to fill the furrow left by the disk opener and cover the seed

much deeper than planted. When placed at a 12 cm (1/2 inch) depth, the seed will probably be in

moist soil. Germination and emergence may occur in 5 to 7 days or less when the soil is warm

and moist.

Insect concerns: Grasshoppers, crickets, corn flea beetles, and other insects can be a problem

with new seedlings. When all green plants (forage for insects) in a field are killed with herbicides,

insects may cause severe damage to newly emerging seedlings. Horse nettle is a host for corn

flea beetle. If small pin-size holes appear in horse nettle leaves, corn flea beetles are likely

present in the field and may damage switchgrass seedlings. No insecticide has label clearance

for use on switchgrass, however, research data have shown a consistent advantage to the use of

a granular systemic insecticide placed in the row with the seed at planting. An alternative may be

to broadcast an insecticide along with the herbicide when applied just before planting. Careful

monitoring of early seedling growth is essential. If seedlings become unthrifty or have necrotic

streaks along the leaf, an insecticide may be needed.

Post emergence management in the seeding year: Grassy weed competition can be

minimized by clipping weeds above the leaves of seedlings. Switchgrass leaf removal should not

be made in the seedling year. Broadleaf weeds can be controlled with light rates of 2,4-D and/or

Banvel, but apply only after the seedlings have four fully expanded leaves. Delay the use of

herbicides as long as weeds are not competing for sunlight or soil water to reduce the potential

for seedling damage. Growth by mid September may be 50 to 75 cm (20 to 30 inches) tall. At this

time, cattle can be used to graze enough to remove about 1one-half the leaf area. Be careful not

to over-graze, or the stand may be weakened. Once frost has killed the leaves, cattle can graze

without restriction. The fine stems and leaves will have low protein, but will provide considerable

value as stockpiled forage. After frost, the switchgrass also can be baled.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

242

Management of Established Stands

Use of an herbicide would be ideal in the first year after seeding or any time weeds are a problem

in an established stand. Research has shown established switchgrass to be very tolerant of

simazine and atrazine; however, there is no label clearance for their use. Simazine at 2.2 a.i. kg

ha-1 (2 lb. per acre) applied in early May has been effective for weed control in research tests.

Simazine can be applied after switchgrass has developed leaf area with no concern for foliar

burn. If perennial triazine-tolerant broadleaf weeds are present, a tank mix that includes

simazine, 2,4-D, and/or Banvel can be used after switchgrass and problem weeds emerge.

Gramoxone, if applied before switchgrass emerges can minimize growth of cool-season species.

Maintenance fertility: Soil samples should be taken no deeper than 10 cm for testing of soil-P

and to about 20 cm for soil-K. Apply P and K as needed to maintain medium soil test levels.

Applications of fertilizer may not be needed, especially if switchgrass is used for grazing, since

animals return most of the nutrients as manure and urine. Soil pH of five or above is satisfactory

for maximum potential yields. Nitrogen may be needed at about 44 to 55 kg ha-1 (40 to 50 lb

acre-1) after the first hay cut or the first time a paddock is rotationally grazed. Where early season

growth is slow and yellowish or maximum first growth is needed, then N may be needed in mid

May.

Hay harvest: First hay harvest should be taken at late boot stage of development. This will occur

by June 15 to 25 for Indian and other upland types at a latitude such as Virginia’s. Cutting at 20 to

25 cm (8 to 10 inches) will benefit regrowth. Cutting closer will not give much more hay value,

because few leaves remain on the stubble. Leaving nodes (joints) on the stems in the stubble will

give sites for axillary tiller formation. These tillers will provide early leaf area development and

energy for fast regrowth. The stiff stubble will discourage overgrazing of regrowth if pastured. A

second hay cutting can be expected in mid August.

Grazing management: Grazing can begin about May 20 to 25. Growth is very rapid for the first

few weeks. Begin grazing when there is about 45 cm (18 inches) of growth for the first early

growth and discontinue grazing to leave 30-cm (12-inch) of stubble. Controlled grazing is the best

management. Begin early and initially rotate often. Under favorable conditions, about 5 weeks are

needed for approximately 70 to 80 cm (28 to 32 inches) of regrowth before grazing a paddock

again. If the next paddock is ready for grazing before the current paddock is grazed close

enough, consider making hay and skipping to another paddock in the sequence. When

switchgrass quality is low consider creep grazing where calves have access to high quality

pasture as the cows clean up before moving on. Simply lifting the electric fence can allow for a

creep. Continue grazing until late August if enough forage is available.

Grazing productivity: Each acre of switchgrass will produce about 200 animal unit days (AUD)

of grazing when properly managed. This assumes one AUD is equivalent to feed required by one

1100 kg (1000 lb.) mature nonlactating cow maintaining constant body weight. One AUD is also

equal to 19.4 kg (17.6 lb.) of forage intake per day (1.76 percent of body weight) if the feed

source is 60% digestible (60% TDN). If the grazing season is 90 days, then each acre can

support 2.2 animal units (AU). This would be 0.20 ha (0.45 acres) per AU. For controlled grazing,

with 5 days of grazing per paddock before rotating and 35 days rest, eight paddocks would be

needed in the system. A 270 kg (600 lb.) stocker (0.7 AU) should gain 0.9 kg (2 lb.) per day. Each

ha could handle 1.3 stockers (3.2 per acre) which is equivalent to 7 kg live weight gain per day

per ha (6.4 lb. per acre). For the 90-day season, there could be a potential of 300 kg live weight

per ha (576 lb. per acre). Clipping pastures after grazing usually will not be needed. If a stubble of

25 to 30 cm (10 to 12 inches) exists then intense close spot grazing will be minimized.

The number of switchgrass acres needed depends on individual situations. A 12-month grazing

system for beef cattle would be ideal. A 12-month system would perhaps require 0.4 ha (1 acre)

of stockpiled tall fescue per animal unit. The tall fescue will provide pasture for 3 to 4 months in
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

243

December through March and some pasturage or hay in the spring. Switchgrass, as noted above,

can provide forage for one AU for 90 days from 0.18 ha (0.45 acre). Some additional pasture will

be needed during April and May, as well as September through November, for an equivalent of

150 days. If the additional pasture has a production potential of 150 AUD acre, one ha (2.45

acres) of pasture may be needed for a 12-month grazing program (1 acre tall fescue, 0.45 acre of

switchgrass and 1 acre of native cool-season pasture). This would be 15 to 20% of the pasture

acreage as switchgrass. Another option would be to have about 0.16 ha (0.4 acre) of switchgrass

per AU.

Late season management: Little growth will occur after late August in latitudes above 35°.

Growth in September until killed by frost will allow the plants to get ready for the winter. After

leaves turn brown, cattle can graze without hurting the stand, since the plants are dormant.

Where cool-season grasses or weeds occur in the spring, cattle can graze until new growth of

switchgrass emerges in late April to early May. Gramoxone can be used any time the

switchgrass is dormant and will suppress the cool-season species.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

244

Establishment of Warm-season Grasses With and Without the Use of

Compost Soil Amendments

Matthew C. Perry, Peter C. Osenton, Gregory A. Gough, and Edward J. R. Lohnes1

Increased interest in wildlife biodiversity and the restoration of wildlife habitats and populations

makes it appropriate to study habitat enhancement techniques. Numerous types of soil

amendments using organic compost materials have been tried in the past to improve soil quality

(Garland et al. 1995), but little data are available that compare these materials from a wildlife

perspective. Several areas of Patuxent Research Refuge (Laurel, MD) have been degraded by

human activities and provide excellent study sites. The data gathered on enhanced habitats

provide essential information for the proper management of wildlife habitats and populations.

Special emphasis was placed on the role of compost in the establishment and retention of native

warm-season grasses [big bluestem, Andropogon gerardii Vitman; little bluestem, Schizachyrium

scoparium (Michx.) Nash, and Indiangrass Sorghastrum nutans (L.) Nash].

Many of the techniques developed from this study could be used for managing restored game

and non-game wildlife populations that benefit from an abundance of plant seeds and

invertebrates. The wild turkey [Meleagris gallopavo] is a species of interest to the hunting

community and represents a native species that is being restored to its original range (Kennamer

1994, Lewis 1987). Other species that are of interest to hunters and could benefit from this

management technique include the mourning dove [Zenaida macroura] and Northern bobwhite

[Colinus virginianus].

Non-game species that have declined in recent years include the meadowlark [Sturnella magna]

and grasshopper sparrow [Ammodramus savannarum]. Data from the Breeding Bird Survey

(Robbins et al. 1995; Sauer et al. 1999) indicate that the meadowlark has declined an average of

4.6 % during the period 1966-1998 and the grasshopper sparrow has declined an average 6.3 %

during the same period in Maryland. Causes of these declines have been loss and degradation

of habitat (Smith 1963; Laughlin and Kibbe 1985).

The objective of this study was to evaluate the use of two compost materials (COMPRO and

LEAFGRO) to enhance wildlife habitats in comparison to control plots, with and without warmseason grasses.

Methods

This study was conducted at two sites at Patuxent Research Refuge. One site (Range 20) was a

degraded military firing range of the U. S. Army that used this land prior to 1992. The other site

(Shaefer Farm) was an abandoned farm that had been intensively farmed until 1975. Two types

of compost (COMPRO and LEAFGRO) were used to improve quality (nutrients and tilth) of the

soil and both were commercially available. COMPRO is made from human sewage sludge and

wood chips and LEAFGRO is made of organic yard waste (grass and leaves).

Two 50 x 100 meter sections of each site were plowed and disked in April and again in May 1996.

The blocks were gridded into 8, 25 X 25 meter square plots (0.06 hectares) using PVC stakes in

each corner. The two soil treatments and two types of controls were randomly assigned to the 8

plots and replicated two times. A 2.5 cm (one inch) layer of COMPRO and LEAFGRO was

applied with a modified manure spreader and disked into the soil to a depth of 7.6 cm (3 inches).

Control plots received no amendments and were of two types: one that was planted with a warm

season grass mixture (Andropogon gerardii, Schizachyrium scoparium, and Sorghastrum nutans)

 

1

 USGS, Patuxent Wildlife Research Center, 11410 American Holly Drive, Laurel, Maryland

20708 USA
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

245

and one that was not planted. Plots receiving compost were also planted with a warm season

grass mixture. Five separate tests conducted to determine if weed seeds existed in the compost

material, revealed no germination of plants.

Three randomly selected meter-square quadrats were established in each treatment and control

plot and permanently marked with a PVC stake. Sampling of the quadrats was conducted in

October 1996-99. October was selected as the sampling month because most warm-season

grasses and other open-field plants had reached their maximum growth for the year. All plants

were identified by species. Percent cover was estimated for each plot. Standard analysis of

variance tests were used to detect differences between sites and among treatments.

Sampling for invertebrates was conducted four days each month (June-Oct 1997 and 1998) with

the use of a 19-liter (five-gallon) bucket (pit-fall trap) placed in the soil in the middle of each plot

level with ground surface. Invertebrates were also sampled by sweeping the vegetation with

capture nets during August 1997. In addition, earthworms were counted from soil samples taken

from each plot in August 1997. All invertebrates were identified and counted.

Pitfall traps also were used to capture small mammals, amphibians, and reptiles that use the

areas. Trapping for small mammals with Sherman live traps placed in each plot was conducted

during the four-day period that pit-fall trapping was conducted. Bird surveys were conducted from

the outside of the plots and then immediately after by walking through the plots. All birds seen by

each technique were recorded by plot number.

Results

In late October 1996, initial vegetation sampling was conducted in three randomly selected meter

square quadrats in each plot. These preliminary results indicated that greatest vegetation cover

occurred in plots treated with LEAFGRO and that plots treated with COMPRO had less

vegetation cover than both types of control plots (with and without warm-season grasses). The

reduced plant growth in the plots treated with COMPRO could have been related to the much

higher soil pH of these plots on both sites (Table 1).

Table 1. Average soil variables for the two compost treatments and the two controls at Range 20

and Shaefer Farm, in 1996 at beginning of study.

O. M.

pH

P2O5

K2O

COMPRO

3.6

7.6

165

95

LEAFGRO

3.8

6.7

221

363

CONTROL

PLANTED

1.7

6.3

55

82

CONTROL

UNPLANTED

1.8

6.6

91

77

After four years of growth, however, the percent cover of the warm-season grasses was greater

in the planted plots that did not receive soil amendments (Table 2). Indiangrass was more

abundant on the sites than either of the other two species of warm-season grasses. There were

differences between the sites with Range 20 having better growth of warm-season grasses than

at Shaefer Farm.

Initial invertebrate sampling in pitfall traps in 1996 indicated that there were more invertebrates in

the LEAFGRO plots. Increased invertebrates appeared to be directly related to the increased

vegetative cover in the LEAFGRO plots. However, when data from 1996 and 1997 were

combined (Table 3) there were no major differences in invertebrate abundance among the plots.

A total of 12,861 invertebrates were recorded from 1996 and 1997 (3297 in COMPRO, 2586 in

LEAFGRO, 3386 in Control/Planted, and 3592 in Control/Unplanted). The relatively smaller
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

246

number of crickets [ERYLLIDAE] in the LEAFGRO plots is unexplainable. Analyses of

invertebrates collected from soil samples and sweep nets also did not reveal major differences

among the plots.

Table 2. Average percent cover of planted species, volunteer species, and no cover in meter

square plots at Range 20 and Shaefer Farm, in 1999 after four years of growth.

RANGE 20

PLANTED

VOLUNTEER

NO COVER

SHAEFER FARM

PLANTED

VOLUNTEER

NO COVER

COMPRO

24

73

3

22

58

20

LEAFGRO

18

78

3

36

59

5

CONTROL

PLANTED

60

25

15

41

33

26

CONTROL

UNPLANTED

0

98

2

0

88

12

Table 3. Total invertebrate organisms captured in pitfall traps at Range 20 and Shaefer Farm, in

1997-98.

 TAXA

ARACHNIDA

COLEOPTERA

DIPLOPODA

ERYLLIDAE

FORMICIDAE

GASTROPODA

LEPIDOPTERA

ORTHOPTERA

OTHERS

COMPRO

328

979

36

1515

49

25

23

84

258

LEAFGRO

336

840

45

878

67

97

32

47

244

CONTROL

PLANTED

354

832

27

1783

25

64

15

61

225

CONTROL

UNPLANTED

394

940

22

1683

94

69

26

77

287

 TOTAL 3297 2586 3386 3592

Although no mammals were captured in Sherman Live Traps in 1996, a total of 60 small

mammals were captured in 1997 (Table 4). Overall, five mammal species were captured and

most were in the plots treated with compost. A total of 21 mammals was caught in the COMPRO

plots, 27 in the LEAFGRO plots, 11 in the Control Planted plots and 1 in the Control Unplanted

plots. The meadow vole [Microtus pennsylvanicus] was the most commonly caught species with

12 in the COMPRO plots, 10 in the LEAFGRO plots, 3 in the Control Planted plots and 0 in the

Control Unplanted plots.

Seven species of amphibians and one reptile species were recorded in the study sites from 1996

and 1997 sampling, but no trend due to treatment could be detected. Hopefully, more sampling

in the future will provide additional data to determine if differences occur due to treatment. Nine

species of birds were observed in the plots during surveys conducted in 1997 (Table 5).

Sparrows were most commonly observed and most were in the plots treated with soil

amendments.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

247

Table 4. Total number of mammals captured in Sherman live traps at Range 20 and Shaefer

Farm, in 1998.

 SPECIES

Masked Shrew

Short-tailed shrew

Meadow Vole

White-footed mouse

House Mouse 

COMPRO

1

0

12

2

6

LEAFGRO

3

2

10

3

9

CONTROL

PLANTED

0

0

3

0

8

CONTROL

UNPLANTED

0

0

0

0

1

 TOTALS 21 27 11 1

Table 5. Total number of birds recorded in treatment and control plots at Range 20 and Shaefer

Farm, in 1998.

 SPECIES

Amer. goldfinch

Carolina chickadee

Dark-eyed junco

Eastern bluebird

Eastern phoebe

Mourning dove

Savannah sparrow

Song sparrow

Swamp sparrow

COMPRO

4

1

7

5

2

LEAFGRO

1

15

8

9

CONTROL

PLANTED

2

2

2

5

3

CONTROL

UNPLANTED

3

1

11

5

4

 TOTAL 19 33 14 24

Conclusions

Numerous areas in the East have been degraded by human activities that could possibly benefit

from soil enhancement with compost amendments. Two compost materials (COMPRO and

LEAFGRO) were evaluated as soil amendments to enhance wildlife habitats, while maintaining

optimal floral and faunal biodiversity. Results after one year indicated that at least one compost

material (LEAFGRO) would increase the quality and quantity of vegetation. However,

invertebrate populations did not increase in these areas. There did appear to be an increase in

meadow voles in the LEAFGRO plots. Results from this study after four years, however,

indicated that warm-season grasses and invertebrates did not benefit from compost, and only

small mammals appeared to respond positively to the soil amendments. It is doubtful if larger

quantities of compost would show more significant changes in the flora and fauna of these

habitats.

Acknowledgments

Persons who provided technical advice included L. Brown, F. Gouin, R. Green, R.

Hammerschlag, N. Melvin, G. Meyer, H. Obrecht, P. Peditto, and J. Patterson. L. Gordon and G.

Sumeriski did agricultural preparation of the plots. Numerous assistants helped collect the data

on this study including B. Bauman, R. Dault, D. Dubois, J. Fitzgerald, A. McDonald, T. Sliwa, J.

Steinberg, C. Stoll, and S. Tanata. Partners on this study include the Environmental Protection

Agency, Quail Unlimited, and MD Department of Natural Resources.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

248

References

Garland, G.A., T.A. Grist, and R.E. Green. 1995. The compost story: from soil enrichment to

pollution remediation. Biocycle 36:53-56.

Kennamer, J.E. 1994. Role of winter habitat in wild turkey survival. Turkey Call. 94:8-9.

Laughlin, S.B. and D.R. Kibbe. 1985. Atlas of breeding birds in Pennsylvania. Univ. of Pittsburgh

Press, Pittsburgh, PA.

Lewis, J.B. 1987. Success story: wild turkey p. 30-43. In U.S. F.W.S. (ed.) Restoring America’s

wildlife. U.S. Govt. Printing Off., Washington, D.C.

Robbins, C.S., D. Bystrak, and P.H. Geissler. 1995. The Breeding Bird Survey: the first fifteen

years. U. S. Fish and Wildl. Serv. Res. Publ. No. 157.

Sauer, J.R., J.E. Hines, I. Thomas, J. Fallon, and G. Gough. 1999. American breeding bird survey

results and analyses 1966-1998. Version 98.1, USGS Patuxent Wildlife Research Center, Laurel,

MD. http://www.pwrc.usgs.gov.

Smith, R.L. 1963. Some ecological notes of the grasshopper sparrow. Wilson Bull. 75:159-165.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

249

Effect of Two Long-term Mowing Regimes on Vegetation

Matthew C. Perry and Amy S. Deller1

Wildlife managers have for many years been interested in the role of mowing as a management

technique to benefit wildlife. Patuxent Research Refuge (Laurel, MD) was established in 1936

and has conducted habitat management studies for many years. When the Refuge was

established, the Snowden family residence (now called Snowden Hall) was surrounded by

neglected overgrown lawns and old farm fields. Snowden Hall was immediately occupied by

government workers and the lawns around the building were mowed on a fairly regular basis to

maintain a satisfactory appearance. Three residences were constructed northwest of Snowden

Hall between 1939 and 1941 and a similar lawn was maintained in front of these buildings. To

the southeast of these two lawn areas and across a road, were two meadows that were

maintained as hay fields as part of the farm wildlife program conducted at Patuxent.

The meadows were originally mowed 1-2 times a year for a hay crop, but in the mid 1960s the

meadows were mowed annually with a brushhog to retard succession of woody vegetation and

maintain the meadow habitat. All lawn and meadow areas at Patuxent received annual

applications of fertilizer and lime until 1972 when these applications ended.

In 1997, all mowing at Patuxent was halted as a way to reduce maintenance costs. The lack of

mowing and the subsequent growth of plants, with diagnostic fruiting parts, allowed a unique

opportunity to identify all plants and estimate ground cover for each species. This paper reports

the findings of this one-year study that was conducted to determine the dominant plants found

growing under two mowing regimes.

Numerous studies have been conducted that evaluate the effect of mowing on vegetation and the

resultant wildlife habitat (Frawley and Best 1991, Warner et al. 1992, Edge et al. 1995). Several

researchers have implicated the mowing frequency or time of year as a factor causing declines of

birds nesting in hayfields (Robbins et al. 1986, Warner and Etter 1989, Bollinger et al. 1990).

These studies tend to show advantages to birds by delaying the time of mowing and reducing the

frequency of mowing. No studies were found that compared the effects of two different long-term

mowing regimes in the same area.

Methods

The mowing regimes for this study included areas that had been mowed with rotary mowers

approximately every 2-4 weeks and meadow areas that were mowed approximately once a year

with a brushhog. Each regime had two replications. The two lawn areas (Lawn A and B) were

0.63 ha and 0.33 ha and the two meadow areas (Meadow A and B) were 0.54 ha and 0.89 ha in

size, respectively. Vegetation was sampled in 20 1-m2

 quadrats that were randomly selected in

each area (n=80). All sampling of the plots was conducted between May 27 and June 11, 1997.

Percent cover was estimated by species in each quadrat. Ground areas where no plants occurred

were recorded as no cover.

On July 11, 1997, vegetation in all quadrats was cut with pruning shears at 10 cm above the

ground and placed in paper bags. The bags were placed in an attic for drying from July 1997 to

February 1998 during which temperatures ranged from 15-35°C. In February two of the samples

were weighed and then placed in an oven at 38°

C for six hours and checked several times to

 

1

USGS, Patuxent Wildlife Research Center, 11410 American Holly Drive, Laurel, Maryland 20708

USA
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

250

determine if a constant weight had been reached. Because of minor changes in weight all other

samples were assumed to be dry and were weighed without further drying.

The average percent ground cover of each plant species was compared using a Wilcoxon nonparametric 2-sample test. The average weights of dried plant material from all quadrats were

compared using a Student’s t-test. A probability level of 0.01 was chosen for determining

statistical significance in all tests.

Results

Analyses of data indicated that all but two plant species that accounted for over 1.00% of ground

cover, showed significant differences between the two treatments (Table 1). The percent ground

cover of the dominant vegetation on the lawn area was 40.0% red fescue [Festuca rubra L.],

26.5% white clover [Trifolium repens L.], and 18.0% Kentucky blue grass [Poa pratensis L.].

The percent ground cover of the dominant vegetation in the meadow area was 33.2% meadow

fescue [Festuca pratensis Huds.], 9.9% sweet vernal grass [Anthoxanthum odoratum L.], 9.2%

orchardgrass [Dactylis glomerata L.], 6.3% Japanese honeysuckle [Lonicera japonica Thunb.],

and 5.2% red fescue. White clover was not found growing in the meadow areas. All percent

ground covers for the dominant vegetation were significantly different (P<0.01) between the two

regimes.

Species richness was higher in the meadow regime (74) versus the lawn regime (33). Frequently

mowed lawn areas may provide better grazing forage for herbivores, such as geese, rabbits, and

deer, however, meadow areas may provide greater biomass (232 vs. 63 g m-2) and greater

diversity of plant species. The meadow regime also appeared to have greater seed production

and cover which is favored by a wider variety of wildlife species, especially passerine birds and

small mammals.

The percent ground cover of the dominant species in the meadow area was 33.2% for meadow

fescue, which was only recorded covering 5.0% of the lawn areas. Sweet vernal grass was the

second most dominant plant species in the meadow covering 9.9% of the ground compared to

0.8% of the lawn area. Orchardgrass covered 9.2 % of the meadow quadrats, but was not

recorded in the lawn areas. The exotic Japanese honeysuckle covered 6.3% of the meadow

areas, but was not recorded in the lawn areas. All percent ground covers for the dominant

vegetation were significantly different (P<0.01) between the two areas. The average percentage

bare ground was 1.0% for the lawn area and 9.4% for the meadow areas, which was significantly

different (P<0.01) between treatments.

Other species that accounted for less than 1.00% of ground cover in both treatments, but were

significantly different (P<0.01) between treatments included wild onion [Allium sp.], dogbane

[Apocynum cannabinum L.], mouse-eared chickweed [Cerastium arvense L.], deertongue,

autumn olive [Elaeagnus umbellata Thunb.], velvet grass, yellow sorrel [Oxalis stricta L.], Virginia

creeper, common cinquefoil, dandelion [Taraxacum officinale Weber ex F. H. Wigg. group], low

hop clover, corn speedwell [Veronica arvensis L.], vetch [Vicia spp.], and grape [Vitis sp.]. The

meadow areas had a total of 74 species, whereas the lawn area had only 33 species.

Biomass was significantly greater (P<0.01) in the meadow area with less frequent mowing than

the lawn area. Weights of vegetation in meadow areas ranged from 103.7 g to 394.8 g, with an

average of 232.2 g. Weights of clipped vegetation from the quadrats in the lawn areas ranged

from 6.4 g to 166.4 g with an average of 63.0 g. Meadow A had six quadrats with woody

vegetation that averaged 64.3 g per plot. The greater biomass produced by the meadow areas

was expected.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

251

Table 1. Average percent cover (±1 SD) of plants recorded (>0.05%) in quadrats of lawn and

meadow areas1

 of Patuxent Research Refuge, June 1997.

SPECIES 2 % COVER (±1 SD)

SCIENTIFIC NAME COMMON NAME LAWN MEADOW

Agrostis sp. Bent grass 1.0 (0.7) 0.0 (0.0)

Anthoxanthum odoratum L. Sweet vernal grass 0.8 (0.6) 9.9 (2.4)

Cerastium arvense L. Mouse-eared chickweed 0.6 (0.2) tr (tr)

Cynodon dactylon (L.) Pers Bermuda grass 1.0 (0.7) 0.0 (0.0)

Dactylis glomerata L. Orchard grass 0.0 (0.0) 9.2 (2.0)

Dichanthelium clandestinum (L.)

Gould

Deertongue 1.7 (0.7) 0.0 (0.0)

Festuca pratensis Huds. Meadow fescue 5.1 (1.3) 33.2 (4.1)

Festuca rubra L. Red fescue 40.0 (4.1) 5.3 (2.0)

Holcus lanatus L. Velvet grass 3.5 (0.8) 0.0 (0.0)

Lespedeza cuneata (Dum. Cours.)

G. Don

Bush clover 0.0 (0.0) 3.9 (1.6)

Liquidambar styraciflua L. Sweetgum 0.8 (0.4) tr (tr)

Lonicera japonica Thunb. Japan. Honeysuckle 0.0 (0.0) 6.3 (0.9)

Parthenocissus quinquefolia (L.)

Planch.

Virginia creeper 0.0 (0.0) 1.9 (0.4)

Plantago lanceolata L. English plantain 1.7 (0.4) tr (tr)

Poa pratensis L. Kentucky bluegrass 18.0 (2.2) 0.4 (0.2)

Potentilla simplex Michx. Old-field cinquefoil 1.0 (0.3) 0.3 (0.2)

Rosa multiflora Thunb. Multiflora rose 0.0 (0.0) 1.4 (0.5)

Rubus sp. Blackberry 0.0 (0.0) 1.5 (1.3)

Rumex acetosella L. Sheep sorrel 1.5 (0.6) tr (tr)

Toxicodendron radicans (L.)

Kuntze

Poison ivy tr (tr) 3.1 (0.6)

Trifolium dubium Sibth. Low hop clover 1.2 (0.3) tr (tr)

Trifolium repens L. White clover 26.5 (2.5) 0.0 (0.0)

No Cover 1.0 (0.3) 9.4 (1.3)

1

 All species and no cover significantly different (P<0.01) between treatments except Bent Grass

and Bermuda grass.

2

 Scientific and common names follow Brown and Brown (1972, 1984).

CONCLUSIONS

Two long-term mowing regimes (60 years of similar management) were evaluated at Patuxent

Research Refuge during the summer of 1997 to better understand the influence of mowing on

vegetation communities. The results indicated greater species richness in areas with less

mowing. The lawn area that was frequently mowed was dominated by plant species that grow to

less height than those species in the meadow habitat. Lawn species were typically those that are

preferred by grazing species such as geese, rabbits, and deer. Meadow areas had greater

diversity of species, more plants that produce seed, and greater overall biomass. Unless

managers especially want to favor herbivores that need large grazing areas, it appears from this

study that a greater diversity of wildlife would benefit if habitats were mowed less frequently.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

252

Less mowing would also discourage brown-headed cowbirds [Molothrus ater], which do not feed

in fields with high vegetation, but use lawns extensively.

One concern that managers have with meadow management is the invasion of the areas by

woody plants. These habitats in the East cannot be maintained without periodic mowing unless

fire management is employed. The advantage of fire management over mowing is that it can be

done less frequently and still control invading woody vegetation. Another aspect that was not

evaluated in this study is the effect of mowing on nutrient quality of plants. It is most likely that

the more frequently mowed areas have less fiber and higher protein in the plants, which would be

expected based on numerous other studies (Harlow 1991). To better evaluate the various factors

affecting the quality of wildlife habitat by management techniques such as mowing, it would be

beneficial to conduct replicated studies with several techniques conducted concurrently.

Acknowledgments

Numerous assistants helped collect the data on this study including B. Bauman, R. Dault, D.

Dubois, P. Osenton, J. Rigelman, and C. Stoll. Advice on statistical analyses was provided by J.

Hatfield and review of manuscript was conducted by D. Boone, F. Fallon, M. Gormley, R.

Hammerschlag, G. Meyer, H. Obrecht, III, and C. Rewa.

References

Bollinger, E.K., P.B. Bollinger, and T.A. Gavin. 1990. Effects of hay-cropping on eastern

populations of the bobolink. Wildl. Soc. Bull. 18:142-150.

Brown, M.L., and R.G. Brown. 1972. Woody plants of Maryland. Port City Press, Baltimore, MD.

347 pp.

Brown, M.L., and R.G. Brown. 1984. Herbaceous plants of Maryland. Port City Press, Baltimore,

MD. 1127 pp.

Edge, D.W., J.O. Wolff, and R.L. Carey. 1995. Density-dependent responses of gray-tailed voles

to mowing. J. Wildl. Manage. 59(2):245-251.

Frawley, B.J. and L.B. Best. 1991. Effects of mowing on breeding bird abundance and species

composition in alfalfa fields. Wildl. Soc. Bull. 19:135-142.

Harlow, R.F. 1991. The effect of management treatments on the biomass, nutritive quality, and

utilization of deer forages on utility rights-of-way. Ph.D. Dissert. Clemson Univ., Clemson, SC.

114pp.

Robbins, C.S., D. Bystrak, and P.H. Geissler. 1986. The Breeding Bird Survey: its first fifteen

years, 1965-1979. U. S. Fish and Wildl. Serv. Resource Publ. 157. 196 pp.

Warner, R.E., and S.L. Etter. 1989. Hay cutting and the survival of pheasants: a long-term

perspective. J. Wildl. Manage. 53:455-461.

Warner, R.E., L.M. David, S.L. Etter, and G.B. Joselyn. 1992. Costs and benefits of roadside

management for ring-necked pheasants. Wildl. Soc. Bull. 20:279-285.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

253

Eastern Gamagrass Responses to Defoliation Management

Paul R. Peterson, Stephen J. Hutton, A. Ozzie Abaye,

Dale D. Wolf, and G. Brinkley Benson1

The lack of a dependable supply of high quality forage during summer is a major limitation to the

profitability of ruminant livestock operations in the mid-Atlantic region. Cool-season perennial

grasses predominate in the region’s pastures and hayfields. Warm-season species are often

limited to volunteer annuals and perennials that lack productivity and/or palatability.

Eastern gamagrass [Tripsacum dactyloides (L.) L.] is a native warm-season perennial grass that

is receiving attention for its potential as livestock feed. Eastern gamagrass has demonstrated

tremendous forage yield potential. In Southern Illinois, an established stand of ‘PMK-24' eastern

gamagrass receiving 133 lbs N acre-1 year-1 produced over 10 tons DM acre-1 in 3 to 4 cuttings

year-1 to a 1.5-inch stubble height (Faix et al. 1980).

Animal performance on eastern gamagrass has also been favorable. Horner et al. (1985)

reported 50 versus 53 lbs milk day-1 from dairy cows consuming eastern gamagrass versus

alfalfa hay, respectively, with grain supplement. The superior milk production on alfalfa was

attributed primarily to greater intake. With wethers however, eastern gamagrass and alfalfa hay

had similar digestibility. Burns et al. (1992) reported steer gains of 1.8 lbs day-1 on continuouslystocked ‘Pete’ eastern gamagrass pasture as compared to only 0.7 lbs day-1 on similarly

managed bermudagrass pasture in North Carolina. In Arkansas, steers gained 2.2 lbs day-1 on

‘Pete’ eastern gamagrass during early summer and up to 450 lbs acre-1 over the season under

continuous stocking.

Information is lacking on defoliation management of eastern gamagrass. Brejda et al. (1996)

reported that a 6-week harvest interval produced greater forage yield than a 4-week harvest

interval in northern Missouri. We were interested in the combined influence of frequency and

intensity of defoliation on yield and quality of eastern gamagrass forage in the mid-Atlantic region.

Our goal was to identify a defoliation management regime that would optimize forage quality

without sacrificing significant forage yield.

Methods

A field experiment was initiated on a 5-yr-old stand of ‘Iuka’ eastern gamagrass in spring 1997.

The site was a Shottower cobbly loam at the Virginia Tech Kentland Farm, Whitethorne, VA (near

Blacksburg). The soil pH was maintained at 6.1 to 6.3, and P and K were maintained at medium

to high levels throughout the experiment.

Two treatment factors were imposed. One factor was cutting frequency: 2 vs. 4 cuttings per year.

The second factor was residual height: either 5 or 10 inches. The experimental design was a split

block in 3 replicates with cutting frequency as main plots and residual height as subplots. Cutting

dates for the 3 years are shown in Table 1. Stage of maturation of eastern gamagrass harvested

2 times per year was boot to early head, whereas forage harvested 4 times per year was

vegetative.

All plots received 100 lbs N acre-1 year-1 applied as ammonium nitrate in split applications of 50

lbs N acre-1. The first N application occurred in early May each year. The second N application

occurred after the 1st harvest for the 2-cut treatments, and after the 2nd harvest for the 4-cut

treatments.

 

1

 Department of Crop and Soil Environmental Sciences, Virginia Polytechnic Institute & State

University, Blacksburg, VA 24061.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

254

Table 1. Cutting dates for eastern gamagrass at Whitethorne, VA.

Cutting treatment 1997 1998 1999

2 cuts year-1 27 June

26 August

26 June

2 September

18 June

22 September

4 cuts year-1 12 June

10 July

14 August

11 September

16 June

17 July

18 August

17 September

8 June

14 July

13 August

22 September

Forage yield was determined by harvesting a 4.3’ x 17’ swath out of each 7' x 20' plot with a

sickle mower in 1997 and by harvesting a 3' x 17' swath with a flail mower in 1998 and 1999 to

the designated residual heights. A representative sample of the harvested forage was obtained

for dry matter and forage quality determinations. Samples were weighed fresh, dried in a forced

air oven, and weighed dry to determine dry matter content of harvested forage, and ground to

pass a 1 mm screen. Ground samples were analyzed for crude protein (CP), acid detergent fiber

(ADF), and neutral detergent fiber (NDF) concentrations at the Virginia Tech Forage Testing Lab.

Total season yield, season average forage quality, and yield distributions were analyzed by

ANOVA.

Results

Growing season precipitation deviated considerably from 30-yr averages during all 3 years of the

trial (Table 2). In 1997, rainfall was below average every month from April through August except

for July when it was somewhat above average. In 1998, rainfall was well above average from

April through June and again in August, but considerably below average in July. In 1999, rainfall

in April and May was slightly above average, well below average in June and August, but well

above average in July and September. Temperatures were generally below average in 1997 and

above average in 1998 (Table 3).

Total season forage DM yields are presented in Fig. 1. Total season yields of eastern gamagrass

averaged 4.7, 5.9, and 4.4 tons acre-1 in 1997, 1998, and 1999, respectively, and ranged from 3.3

to 7.4 ton acre-1. The high yields in 1998 can probably be attributed to ideal warm-season grass

growing conditions, i.e. above normal temperatures and precipitation.

Four cuttings per year reduced (p<0.05) total season yields of eastern gamagrass 22% compared

to two cuttings per year. The lack of a cutting frequency by year interaction (p>0.05) suggests

that there was no negative carryover influence of frequent cutting from year to year during the 3

year of the trial.

Cutting to a 5-inch residual resulted in greater (p<0.01) harvested yield than cutting to a 10-inch

residual, but there was evidence that the extent of the difference varied by year (p<0.10). In

1997, the yield difference between residual heights was 35%. In years 1998 and 1999, the

difference was only 17%. This difference may have been due to the different harvesting machine

used in 1998-99 versus 1997, but it may also reflect a decreasing yield advantage to close cutting

over years due to reduced vigor. Indeed, the 10-inch residual had considerable green leaf

remaining after harvest, whereas the 5-inch residual did not, particularly with 2 cuttings per year.

There was no cutting frequency by residual height interaction (p>0.05).

Table 2. Monthly precipitation and departures from 30-year averages at the Virginia Tech

Kentland Farm, Whitethorne, VA.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

255

1997 1998 1999

Month Precip. Dep. Precip. Dep. Precip. Dep.

------------------------------------- inches ------------------------------------

Jan. 2.43 0.15 5.86 3.58 3.92 1.64

Feb. 1.94 -0.72 2.55 -0.11 2.07 -0.59

Mar. 4.11 1.06 4.69 1.64 2.50 -0.55

Apr. 2.13 -0.71 4.99 2.15 3.22 0.38

May 2.11 -1.70 5.86 2.05 4.30 0.49

June 3.33 -0.12 3.63 0.18 0.95 -2.50

July 4.79 0.87 1.94 -1.98 6.03 2.11

Aug. 1.88 -1.41 6.10 2.81 2.17 -1.12

Sept. 3.41 0.42 1.13 -1.86 4.60 1.61

Oct. 1.22 -2.12 2.44 -0.90 1.70 -1.64

Nov. 2.59 0.02 0.86 -1.71 2.10 -0.43

Dec. 2.19 -0.54 2.58 -0.15 1.80 -0.90

Total 32.13 -4.80 42.63 5.70 35.36 -1.50

Table 3. Monthly average temperatures from 1997 through 1999 and departures from 30-year

averages at the Virginia Tech Kentland Farm, Whitethorne, VA.

1997 1998 1999

Month Avg. Dep. Avg. Dep. Avg. Dep.

------------------------------Degrees Fahrenheit------------------------------

Apr. 47.3 -3.6 52.6 1.7 53.7 2.8

May 55.3 -5.0 62.9 2.6 58.7 -1.6

June 64.4 -3.2 68.9 1.3 67.3 -0.3

July 72.3 1.0 71.9 0.6 74.6 3.3

Aug. 68.4 -1.8 70.8 0.6 70.8 0.6

Sept. 63.4 -0.3 68.8 5.1 63.2 -0.5

Yield distributions varied with year and residual height for both the 2- and 4-cut treatments (Fig. 2

and 3). During 1998 and 1999, greatest yields occurred in early summer harvests. The

contrasting yield distribution in 1997 can probably be attributed to below average spring

temperatures and precipitation. Yields were consistently less than 1000 lbs acre-1 for the 4th

cutting of the 4-cut treatments. These data suggest that a defoliation regime with earlier and/or

more frequent defoliation during the early summer might be feasible and, in fact, preferable.

Eastern gamagrass forage averaged 8.9% CP, 39.8% ADF, and 74.2% NDF (Fig. 4 and 5).

Averaged over 3 years, four cuttings per year increased (p<0.01) eastern gamagrass CP

concentration 2.7 percentage units and decreased ADF (p<0.01) and NDF (p<0.05)

concentrations 2.9 and 2.2 percentage units, respectively, compared to two cuttings per year.

There were significant year by cutting frequency interactions (p<0.05) for all forage quality

measures because the difference in forage quality between cutting frequencies increased each

year with four cuttings producing comparatively higher forage quality each year.

Residual height had small, inconsistent influences on forage quality, suggesting that managing for

a taller residual did not offer a consistent forage quality advantage. The lack of a biological effect

of residual height may be due to the leafiness of the basal area of eastern gamagrass plants.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

256

The interaction of cutting frequency, residual height, and year was statistically significant for CP

concentration (p<0.01), but probably not biologically important.

Conclusions

Our data confirm the forage potential of eastern gamagrass in the Mid-Atlantic region. Eastern

gamagrass produced an average of 5.0 tons of forage DM per acre. During 3 years of varying

defoliation regimes, eastern gamagrass did not demonstrate sensitivity to close defoliation (5").

This response contrasts to that of other tall-growing native warm-season perennials like

switchgrass and big bluestem, and can probably be attributed to a high level of basal tillering and

meristematic activity in eastern gamagrass.

Frequent defoliation appears to be an effective strategy to improve forage quality; however,

grazing to taller residual height (10 inches) appears to offer no advantage. It should be noted that

our forage quality data provides insight into comparisons within our experiment, but should not be

extrapolated to predict animal performance. The research discussed earlier and considerable

research by Reid et al. (1988) documents that animal performance on native warm-season

grasses often far exceeds what would be anticipated based on a routine chemical analyses of

forage quality.

Acknowledgments: The researchers express their sincere appreciation to the Virginia

Agricultural Council (VAC) for funding this research; to the Virginia Forage and Grassland Council

for supporting the request for funding from the VAC and for partially funding the forage harvester;

and to Dean Andy Swiger, Dr. Bob Cannell, and Dr. Jack Hall for funding the forage harvester.

References

Aiken, G.E. 1997. Temporal effects on steer performance and nutritive value for eastern

gamagrass grazed continuously for different durations. J. Anim. Sci. 75:803-808.

Brejda, J.J., J.R. Brown, T.E. Lorenz, J. Henry, J.L. Reid, and S.R. Lowry. 1996. Eastern

gamagrass responses to different harvest intervals and nitrogen rates in northern Missouri. J.

Prod. Agric. 9:130-135.

Burns, J.C., D.S. Fisher, K.R. Pond, and D.H. Timothy. 1992. Diet characteristics, digesta

kinetics, and dry matter intake of steers grazing eastern gamagrass. J. Anim. Sci. 70:1251-1261.

Faix, J.J., C.J. Kaiser, and F.C. Hinds. 1980. Quality, yield, and survival of Asiatic bluestem and

an eastern gamagrass in southern Illinois. J. Range. Man. 33:388-390.

Horner, J.L., L.J. Bush, G.D. Adams, and C.M. Taliaferro. 1985. Comparative nutritional value of

eastern gamagrass and alfalfa hay for dairy cows. J. Dairy Sci. 68:2615-2620.

Reid, R.L., G.A. Jung, and D.W. Allinson. 1988. Nutritive quality of warm seasons grasses in the

northeast. West Virginia Univ. Agric. and Forestry Exp. Sta. Bull. 699.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

257

Fig. 2. Yield distribution of eastern gamagrass cut two times 

per year for 3 yr at Whitethorne, VA.

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

1997 1998 1999

DM Yield (lb/acre)

1st cut

2nd

Fig. 1. Influence of defoliation frequency and residual height on 

total season forage yield of eastern gamagrass at Whitethorne, 

VA.

0

2000

4000

6000

8000

10000

12000

14000

16000

1997 1998 1999

DM Yield (lb/ac)

2 cut - 5"

2 cut - 10"

4 cut - 5"

4 cut - 10"
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

258

Fig. 3. Yield distribution of eastern gamagrass cut four times 

per year for 3 yr at Whitethorne, VA.

0

1000

2000

3000

4000

5000

6000

1997 1998 1999

DM Yield (lb/acre)

1st cut

2nd cut

3rd cut

4th cut

Fig. 4. Season average crude protein concentration of 

eastern gamagrass forage as affected by defoliation 

management at Whitethorne, VA.

0

2

4

6

8

10

12

14

1997 1998 1999

Crude Protein (%DM)

2 cut - 5"

2 cut - 10"

4 cut - 5"

4 cut - 10"
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

259

Direct Seeding Native Species on Reclaimed Phosphate-Mined Lands

Sharon Pfaff and Mary Anne Gonter1

Abstract

The Florida phosphate industry would like to reclaim mined lands to native upland habitat. Lack

of direct seeding expertise has hampered this effort. The Brooksville, FL Plant Materials Center

has been working with the Florida Institute of Phosphate Research to develop direct seeding

technology for native Florida upland species. A series of studies were conducted on a reclaimed

mined land site of sand tails and sand tails capped with overburden, near Bartow, FL from 1997

through 1999. Research focused on the influence of three factors on establishment success of

wiregrass [Aristida beyrichiana Trin. & Rupr.] and lopsided Indiangrass [Sorghastrum secundum

(Elliott) Nash]: Seeding method, seeding rate and seeding date. Drilling was compared with

broadcasting. Indiangrass and wiregrass that had been debreaded before seeding successfully

emerged from drilled and broadcast treatments in 1997. However, debearding severely damaged

a large percentage of the brittle wiregrass seed, making drilling uneconomical. In 1998,

Indiangrass was planted at 215, 430 and 645 pure live seed m-2. Plant densities were similar for

the high and medium rates, and 2–3 times lower for the low rate. Wiregrass densities were 5

plants m-2 or less from 430, 645 and 860 pls m-2 treatments. Wiregrass could not overcome a

droughty spring and high weed competition at any of the rates used. In 1999, wiregrass and

Indiangrass were seeded in January and May to test influence of seeding date. Despite a

droughty spring, both species emerged relatively well from both treatments. Winter seedings may

be advantageous for wiregrass, but only if weed competition is low and adequate soil moisture is

available.

Introduction

There is a growing movement in Florida, especially in the phosphate industry, to reclaim upland

sites with native species. Direct seeding has the potential to be the most economical method for

revegetation. However, several problems associated with native plants have hampered

reseeding efforts. Seeds from native species are often light, with awns or hairy appendages that

preclude harvest and planting with conventional equipment. Desirable native species often lack

seedling vigor, and are poor competitors with weedy species. In addition, some native species

may undergo seed dormancy, and only germinate during a given season.

In 1995, under a previous agreement with the Florida Institute of Phosphate Research (FIPR), the

Brooksville, FL Plant Materials Center (FLPMC) established seeding methodology trials on two

reclaimed mined land sites near Bartow, FL, using wiregrass and lopsided Indiangrass (Pfaff and

Gonter 1996). Plots were planted in May, at the beginning of the rainy season. Despite problems

with severe competition from introduced pasture species, much information was gathered from

these studies. Indiangrass readily established, although plant densities were low. Wiregrass did

not establish. Low plant densities were thought to be primarily due to the season of seeding,

seeding rate and weed competition. Problems associated with the three seeding methods

employed in this study also contributed to poor stand establishment. Drilling showed potential for

use in establishing Indiangrass. However, the drill used in the initial study was not capable of

handling light chaffy seed.

Bisset (1995) was able to successfully establish several native species, including wiregrass, by

broadcasting chopped mature native material on a reclaimed mined land site near Bartow, FL in

December. Bisset estimated that wiregrass was distributed at a rate of 538 pure live seed m-2 (50

pls ft-2) (personal conversation). In north Florida, Seamon (1998) reported successful wiregrass

 

1

 Sharon Pfaff is Agronomist and Mary Anne Gonter is Biological Technician, USDA NRCS Plant

Materials Center, Brooksville, FL 34601.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

260

establishment when a wiregrass mix collected with a Flail-Vac Seed Stripper was broadcast on

plots of bare mineral soils with a hay blower. The seed was planted in February. Possibly due to

a dry spring, most seedlings did not emerge for two years. Seeding rate was estimated to be

over 3,200 pls m-2 (300 pls ft-2). Wiregrass seedlings emerged well from plots that had been

disked prior to seeding. However, plots that were simply burned off or were not disturbed had no

seedling emergence. It appears that planting into disturbed bare mineral soils is important for

successful wiregrass stand establishment.

The purpose of this study is to determine the effect of seeding method, seeding rate, and planting

date on the establishment of wiregrass and lopsided Indiangrass in monoculture and mix.

Materials and Methods

Lopsided Indiangrass seed was collected from Ft. Cooper State Park from 1995 through 1998

using a Flail-Vac Seed Stripper. Wiregrass seed was collected from Avon Park Air Force

Bombing Range in 1995 through 1998 with the Flail-Vac. Initially, seed from both species was

debearded using a Clipper debearder. Chaff was then removed using an air-screen cleaner.

Purity obtained for the Indiangrass was 95%. Purity of the wiregrass was approx. 50% due to

broken seed. Wiregrass seed is very brittle, and the debearder caused a great deal of seed

breakage. A hammermill appears to be a better instrument for debearding wiregrass seed.

Although awns aren’t as completely removed, and some breakage does occurs in the

hammermill, the seed is not processed as long as in the debearder, therefore breakage is

reduced. After it was determine in 1997 that debearding wiregrass was not economical, only the

Indiangrass seed was debearded. The wiregrass seed was scalped with an air-screen cleaner to

remove large sticks and stems.

The study site is near Bartow, FL, on reclaimed mined lands provided by Cargill Fertilizer, Inc. It

is composed of three acres of sand tailings, and an adjacent three acres of sand tailings capped

with 6 or more inches of overburden soils. Sand tails soils are generally very consistent in

texture, and very coarse and droughty. Texture of the overburden soils at the study site varied

greatly. In areas where the overburden cap was thinnest, a large fraction of the soils were coarse

sands with very low water holding capacity. Soils on the other end of the overburden plots have a

large loam fraction, which has a high water holding capacity, and crusts heavily when dry.

The study site was freshly reclaimed in January of 1997, so no weed control was necessary.

Vacant plots were disked and sprayed with glyphosate throughout the growing seasons from

1997 to 1999 to control weeds. However, heavy late summer rains often interfered with weed

control and allowed [Digitaria sanguinalis (L.) Scop.], natalgrass [Melinis repens (Willd.) Zizka],

and hairy indigo [Indigofera hirsuta L.] to establish seed banks on the overburden site.

All plots were rolled with a cultipacker before seeding. Plots were 10’ x 50’ in size. Due to a lack

of seed, generally 4 reps were used on overburden soils and 3 reps on sand tailing soils. A total

of six series of study plots were planted in January and May 1997 through 1999.

1997 Seedings: The first series was planted on both soil types January 28, 1997 as a randomized

complete block. Monocultures of debearded seed of both grass species were seeded using an

air drill built by Pounds Motor Company of Winter Garden, FL. This drill was specifically designed

to handle light chaffy seed and keep it from bridging in the drill. It has an aggressive brush

system in the hopper, and forced air blowing the seed through the drop tubes. An

Indiangrass/wiregrass/Liatris spp. mixture of debearded seed was also drilled. All monoculture

broadcast treatments used debearded seed, and were planted using a hand-held Cyclone

seeder. A mixture of beards-on wiregrass, debearded Indiangrass and Liatris were broadcast

using a seed blower. All broadcast plots were firmed with a cultipacker after seeding.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

261

The lopsided Indiangrass and wiregrass seeding rate in drilled and broadcast monoculture

treatments was 645 pls m-2 (60 pls ft-2). The exception to this was the wiregrass drill treatment.

It was seeded at a rate of 800 - 860 pls m-2 (75-80 pls ft-2), due to the aggressive brush system of

the air drill. In broadcast mix treatments, wiregrass and Indiangrass were planted at a rate of 645

and 430 pls m-2 (60 and 40 pls ft-2) respectively. Liatris was also added to the January mix

treatments at a rate of 130 pls m-2 (12 pls ft-2).

The second series of plantings were seeded on May 20, 1997 as outlined above. However, drill

treatments were planted using a Tye drill with a warm season grass attachment, borrowed from

the Quicksand, KY PMC. Seeding rates were the same as for the January seeding, except that

wiregrass was drilled at 646 pls m-2.

1998 Seedings: The third series of study plots were seeded on both soil types January 21, 1998.

The only seeding method used was broadcasting, with emphasis placed on seeding rates.

Indiangrass was debearded for this planting, and broadcast with a Cyclone seeder. Beards-on

wiregrass was broadcast in monoculture and mix with a seed blower. Plots were packed before

and after seeding with a cultipacker.

January monoculture plots were broadcast at three rates: Wiregrass - high (860 pls m-2), medium

(645 pls m-2) and low (430 pls m-2); Indiangrass - high (645 pls m-2), medium (430 pls m-2), and

low (215 pls m-2); wiregrass/Indiangrass mixtures - high (430 and 215 pls m-2 respectively) and a

low (430 and 108 pls m-2 respectively). Mixtures contained approximately 55 pls m-2 of Liatris

species. Treatments were replicated four times on overburden soils and three times on sand tails

soils in randomized complete blocks.

The fourth series of plots were planted on May 11, 1998. Indiangrass and wiregrass were

broadcast at one monoculture rate of 645 pls m-2 in the same manner as above. Wiregrass and

Indiangrass were broadcast as a mixture at one rate of 430 and 215 pls m-2 respectively. These

three treatments were planted on vacant plots within the January 1998 study, so that planting

date effects could also be studied.

An additional Indiangrass seeding method was studied for both sand tails and overburden soils in

May of 1998. Treatments compared broadcasting Indiangrass seed with a Cyclone seeder,

versus drilling with a Truax grass drill. Seed was drilled at the approximate rates of 215 and 430

pls m-2, and broadcast at a rate of 430 pls m-2. Slight modifications had to be made to the Truax

to keep the seed from bridging in the drop tubes. Each treatment was replicated 3 times on both

soil types in a randomized complete block design.

1999 Seedings: The fifth series of plantings were made on January 12, 1999. The first study

focused on the effect of seeding date on wiregrass and lopsided Indiangrass establishment.

Wiregrass and Indiangrass were broadcast in monoculture at a seeding rate of 645 pls m-2 in

January in a split plot design, which included May 1999 treatments. Plots were replicated three

times on both overburden and sand tailing soils. Wiregrass seed was not debearded, and was

broadcast with a seed blower. Debearded Indiangrass seed was broadcast with a cyclone

seeder. Plots were packed before and after seeding with a cultipacker. In the second study, the

effect of various rates of Indiangrass on wiregrass emergence was considered. Plots were

planted in January on both soil types. Wiregrass was broadcast at 860 pls m-2 with three different

rates of Indiangrass (0, 108 and 215 pls m-2) and 55 pls m-2 Liatris seed Plots were replicated

three times on both soil types in a randomized complete block design.

The sixth and final series of plots were planted on May 4, 1999 within the January 1999 split

block design. Wiregrass and Indiangrass were seeded using the same rate and methods as for

the January plots.

Meter square quadrats (two per plot) were randomly established on all plots at six months. These

were used to evaluate treatments for plant density, size, vigor, percent canopy cover, and percent
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

262

weed cover at 6, 12 and 24 months after seeding. Statistical analysis was conducted using

MSTAT-C (1983).

Results and Discussion

Weather patterns varied greatly between the three years of this study. Rainfall amounts for

Hooker’s Prairie, which is located within five miles of the study site, are shown in Table 1. The

spring of 1997 was wet, with 7 inches of rainfall recorded at Hooker’s Prairie in April. March and

April precipitation is very critical for winter-planted seedlings. The first three months of 1998 were

reported as being exceptionally wet at Hooker’s Prairie. However, almost no rainfall was received

in the critical month of April. This dry period was also accompanied by high winds. Rainfall

amounts were very low the first four months of 1999. High winds accompanied the dry

conditions, and new seedlings were literally sand blasted on the coarser soils. Precipitation

adequate to sustain May planted seedlings did occur during the summer season in 1998 and

1999.

Table 1. Inches of monthly Rainfall at Hooker’s Prairie from 1996 through 1999.

1996 1997 1998 1999

Inches of Precipitation

January 5.18 0.93 2.50 2.50

February 1.74 0.86 12.58 0.44

March 5.45 2.17 6.84 0.45

April 0.73 7.12 0.37 1.52

May 10.38 1.87 2.07 4.34

June 3.32 6.00 0.83 8.87

July 4.39 9.49 7.31 5.51

August 9.62 2.41 4.29 7.87

September 4.89 8.05 13.01 10.07

October 3.43 3.32 0.30 2.26

November 0.86 5.94 3.11 2.18

December 1.67 8.51 1.94 2.16

Seeding Method: Three types of drills were tested in this study, and two types of broadcast

methods. In the January 1997 planting, the air drill designed by Pounds Motor handled the

debearded Indiangrass and wiregrass seed fairly well. It has an aggressive brush system, which

pulls the seed to the drop tube openers. The seed is then sucked into the drop tubes and blown

through to prevent bridging or clogging. However, the air pressure through the tubes was so

great that it actually blew the seed out of the furrows. Seeding depth was increased to offset this

problem, and the planting depth of the drilled mix was deeper than the planting depth for the

monoculture drill treatments. The air pressure could be adjusted to some extent, however

decreasing the air pressure decreased the amount of seed output. Depth placement using this

drill was difficult to determine because seed was distributed throughout the upper two inches in

the soil.

The Cyclone seeder distributed debearded wiregrass and Indiangrass very uniformly. The seed

blower handled the chaffy wiregrass seed mix very well, though distribution over the surface of

the plots was uneven. The ideal seedbed for this method was a moist soil surface with grooves

for the air-blown seed to collect.

Overall, broadcasting produced the greatest plant densities for both species (Table 2). Direct

seeding success criteria for Florida soils have not been developed. In the western US, 43 plants

m-2 is considered a successful planting (Cook et al 1974). Coarse droughty soils in Florida may

not be able to sustain such high densities. In its natural environment in Florida, mature wiregrass

averages 5 plants m-2 (Clewell 1989). All of the January 1999 Indiangrass treatments met the
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

263

success criteria of 43 plants m-2 on both soil types. A seeding rate of 646 pls m-2 was actually too

high for Indiangrass. After two years Indiangrass densities in broadcast plots had diminished by

approximately 60% on both soil types. Due to excessive competition between seedlings, plants

in broadcast plots were smaller and less vigorous than those in drilled plots. Drilling provided

more optimum seedling placement. Wiregrass, on the other hand, only met the 43 plants m-2

success criteria in the overburden broadcast plots. All other wiregrass treatments averaged at

least 5 plants m-2 or more. Once established, wiregrass seedlings proved to be very persistent.

After two years, wiregrass treatments suffered 10% or less seedling losses.

Table 2. Average plant densities of January 1997 broadcast and drilled Indiangrass and

wiregrass in monoculture on overburden and sand tails soils 6 months after planting.

Treatment Overburden Sand Tails

Plants m-2

Indiangrass – Broadcast (645 pls m-2) 177a* 46ab*

Indiangrass – Drilled (645 pls m-2) 96b 76a

Wiregrass – Broadcast (645 pls m-2) 65b 14bc

Wiregrass – Drilled (860 pls m-2) 36b 5c

 *treatment means followed by different letters are significantly different by Tukey’s HSD at

P≤0.05

Wiregrass and Indiangrass were also drilled and broadcast as a mixture in January of 1997

(Table 3). Even at a reduced seeding rate, Indiangrass dominated the mix and inhibited

wiregrass germination. After two years however, Indiangrass densities decreased 50% or more,

while wiregrass treatments only decreased by 10% or less. Wiregrass actually became the

dominant species in the mix. It appears wiregrass is very susceptible to competition at

emergence, yet, once established this species has excellent persistence.

Table 3. Average plant densities of January 1997 broadcast and drilled mixtures of Indiangrass

and wiregrass on overburden and sand tails soils 6 months after planting.

Treatment Overburden Sand Tails

Plants m-2

Indiangrass in Mix – Broadcast (430 m-2) 88a* 26b*

Indiangrass in Mix – Drilled (430 pls m-2) 79ab 86a

Wiregrass in Mix – Broadcast (645 pls m-2) 39bc 4b

Wiregrass in Mix – Drilled (645 pls m-2) 17c 3b

Mix - Indiangrass & Wiregrass - Broadcast 128 30

Mix - Indiangrass & Wiregrass - Drilled 108 89

 *treatment means followed by different letters are significantly different by Tukey’s HSD at

P≤0.05

The Tye drill used for the May 1997 planting could not handle the seed as well as the air drill

used in January. The Tye drill operated on a gravity flow system. It was able to meter out

debearded Indiangrass seed fairly efficiently. Because the debearded wiregrass seed was very

light, the hopper had to be over half full for it to meter out efficiently. On this drill, the drop tubes

are placed behind the double disk openers. The furrow partially closed up before the seed could

fall into it, causing a large percentage of the seed to be left on the soil surface. Planting depth

was increased to overcome this problem, however placement was not precise. This system

showed no advantages over broadcasting, except for placement of seed in rows, which reduces

competition between seedlings.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

264

Results for May 1997 Indiangrass and wiregrass treatments in monoculture are shown in Table 4.

Greatest densities for both species were again obtained by broadcasting. Indiangrass met the

western success criteria of 43 plants m-2 on overburden but not sand tails drilled treatments. The

Tye drill was not successful in seeding wiregrass, although seeding date may have been a

contributing factor. Broadcast wiregrass treatment densities were low, but still met natural Florida

averages of 5 plants m-2. Weed competition was observed to be higher in May overburden plots

than in January plots, though herbicide treatments were applied prior to planting. Weed

competition undoubtedly contributed to low wiregrass emergence in overburden plots.

Competing weeds were primarily crabgrass, natal grass, and hairy indigo. Indiangrass again

dominated mixture treatments in the May 1997 plantings (Table 5). However, all mixture

treatments preformed poorly on sand tails soils. A dry, windy August may have contributed to

seedling desiccation on the extremely droughty sand tails soils. Almost no wiregrass emerged

from any of the mixture treatments.

Table 4. Average plant densities of May 1997 broadcast and drilled Indiangrass and wiregrass in

monoculture on overburden and sand tails soils 6 months after planting.

Treatment Overburden Sand Tails

Plants m-2

Indiangrass – Broadcast (645 pls m-2) 117a* 34a*

Indiangrass – Drilled (645 pls m-2) 57b 21a

Wiregrass – Broadcast (645 pls m-2) 7c 5a

Wiregrass – Drilled (860 pls m-2) 1c 0.2a

 *treatment means followed by different letters are significantly different by Tukey’s HSD at

P≤0.05

Table 5. Average plant densities of May 1997 broadcast and drilled mixtures of Indiangrass and

wiregrass on overburden and sand tails soils 6 months after planting.

Treatment Overburden Sand Tails

Plants m-2

Indiangrass in Mix – Broadcast (430 m-2) 28a* 2a*

Indiangrass in Mix – Drilled (430 pls m-2) 46a 7a

Wiregrass in Mix – Broadcast (645 pls m-2) 2b 0.3a

Wiregrass in Mix – Drilled (645 pls m-2) 1b 0.2a

Mix - Indiangrass & Wiregrass - Broadcast 30 1

Mix - Indiangrass & Wiregrass - Drilled 47 7

 *treatment means followed by different letters are significantly different by Tukey’s HSD at

P≤0.05

In May of 1998, a Truax grass drill was used to compare drilling with broadcasting Indiangrass.

One of the advantages of drilling is that seed can be placed precisely at a given depth and row

spacing. Seeding rates can also be reduced compared to broadcasting, which leaves

approximately half of the seed on the soil surface. The Truax drill was able to handle the chaffy

Indiangrass seed fairly well. It has a very vigorous auger system that keeps the seed from

bridging, and aggressively pulls it into the drop tubes. As with all new equipment however, some

problems had to be overcome. The disk openers would not turn in the dry sandy soils. The drop

tubes of the chaffy seed box were positioned to open directly over the point where the two blades

of the disk openers met. If these did not turn, the seed would collect there and not be metered

out evenly. This problem was overcome by moving the drop tubes back to another hole. A few of

the appendages on the Indiangrass seed remained after debearding, causing enough resistance

to keep the seed from flowing easily. This problem could be overcome in the future by increasing

processing times in the debearder to more fully polish seed hulls. Leaving Indiangrass seed in
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

265

the debearder longer may cause more seed damage. However, better flowing seed would greatly

increase consistent stand establishment. Broadcast treatments produced very high densities on

both soil types (Table 6), well above success criteria. Drilled treatment densities were

substantially lower than the 43 plant m-2 success criteria, due primarily to poor seed flow.

Doubling drilled seeding rates to broadcast levels did not increase seedling densities. Future

studies need to be conducted to precisely determine optimum drilled Indiangrass seeding rates,

once mechanical difficulties are overcome.

Table 6. Average plant densities of May 1998 drilled and broadcast Indiangrass on overburden

and sand tails soils at 6 months after planting.

Treatment Overburden Sand Tails

Plants m-2

Indiangrass Broadcast -Medium Rate (430 pls m-2) 84a* 97a*

Indiangrass Drilled - Medium Rate (430 pls m-2) 8b 17b

Indiangrass Drilled - Low Rate (215 pls m-2) 9b 14b

*treatment means followed by different letters are significantly different by Tukey’s HSD at P≤0.05

Seeding Rate: Indiangrass and wiregrass were broadcast in monoculture at three seeding rates

in January of 1998 (Table 7). Unfortunately, erratic rainfall and heavy weed competition caused

much variability in the data. Rainfall was unusually heavy the first three months of 1998. This

appeared to stimulate high weed competition on both soil types early in the year, especially on

overburden plots. Lack of any appreciable rainfall in April, coupled with high winds, decimated

populations of the less vigorous native grasses that had emerged. Coarser, sandy overburden

soils had lower weed competition than did overburden soils with a higher clay loam fraction. This

translated to relatively high seedling densities for both species on the sandy replications,

graduating to virtually no surviving seedlings on the heavier soils. The net result was that density

data on overburden plots was erratic, e.g. high seeding rates produced lower seedling densities

than did medium, or in the case of wiregrass, low rates. Some interesting observations could be

made from the Indiangrass treatments. This was the species most able to overcome unfavorable

conditions. Indiangrass seedling densities were similar for the high and medium rates on both

soil types, and approximated success criteria of 43 plants m-2. The low Indiangrass seeding rate

produced substantially lower plant densities than did the medium rate. Based on these data, it

appears that a 215 pls m-2 broadcast seeding rate is definitely too low to meet western success

criteria of 43 plants m-2.

It also appears there is no advantage to doubling the seeding rate to 645 pls m-2. This high rate

has in fact been observed to cause severe competition between seedlings, and high seedling

mortality.

Wiregrass seedling densities were very low and generally did not reach the natural systems

standard of 5 plants m-2 at any seeding rates used in this study. This species appears to be

extremely sensitive to weed competition and rainfall, which had a greater effect on seedling

emergence than did seeding rate.

To test wiregrass seedling sensitivity to competition with other species in a native mix, wiregrass

was broadcast with Indiangrass at three differing rates in January of 1999 (Table 8).

Unfortunately, weather patterns were once again very erratic in 1999. Only 4.9 inches of rain fell

in the first four months of 1999, compared to an average of 15.5 inches for the first four months of

the previous three years. Droughty conditions were accompanied by high winds. Remarkably,

wiregrass densities for all treatments on overburden soils were above the natural system

standard of 5 plants m-2. Fortunately, weed competition was low, and had much less influence on

seedling emergence compared to 1998. Indiangrass densities appeared to be too low to

significantly effect wiregrass emergence under these droughty conditions at either rate. Stand

densities on the sand tails plots were almost zero for all species. Droughty conditions and

blowing sand killed most seedlings that did emerge. These studies provided a good opportunity
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

266

to establish seeding rate thresholds for wiregrass and Indiangrass in monoculture and mixtures.

Further experiments may be necessary to develop data under less extreme conditions.

Table 7. Average plant densities of January 1998 broadcast Indiangrass and wiregrass in

monoculture at three seeding rates on overburden and sand tails soils one year after planting.

Treatment Overburden Sand Tails

Plants m-2

Indiangrass - High Rate (645 pls m-2) 33ab 42a

Indiangrass - Medium Rate (430 m-2) 44a 35ab

Indiangrass - Low Rate (215 pls m-2) 14ab 14ab

Wiregrass - High Rate (860 pls m-2) 3b 4b

Wiregrass - Medium Rate (645 m-2) 4b 4b

Wiregrass - Low Rate (430 pls m-2) 5b 3b

 *treatment means followed by different letters are significantly different by Tukey’s HSD at

P≤0.05

Table 8. Average plant densities of wiregrass broadcast at three different rates with Indiangrass

January 1999 on two soil types at 6 months after planting.

Treatment Overburden Sand Tails

Plants m-2

Rate 1:

Wiregrass (860 pls m-2) 11ab* 0.3a*

Liatris (55 pls m-2) 3bc 1a

Rate 2:

Wiregrass (860 pls m-2) 9ab 1a

Indiangrass – Medium Rate (108 pls m-2) 5abc 2a

Liatris (55 pls m-2) 3bc 2a

Rate 3

Wiregrass (860 pls m-2) 8ab 0.3a

Indiangrass – High Rate (215 pls m-2) 7ab 4a

Liatris (55 pls m-2) 3bc 1a

*treatment means followed by different letters are significantly different by Tukey’s HSD at P≤0.05

Seeding Date: Throughout these studies, seeding date often appeared to have a strong influence

on seedling establishment. A final series of study plots were planted in 1999 to specifically

address the affect of January verses May planting dates on wiregrass and Indiangrass

emergence (Table 9). Droughty weather conditions in 1999 negatively influenced seedling

emergence. However, good data were still obtained. Weed competition fortunately was not a

significant factor in this study. There was no significant difference between wiregrass stand

densities in January verses May on overburden soils. Had more rainfall been received in the

spring of 1999, it is possible that January wiregrass plant densities would have been much

higher. This conclusion is based on wiregrass performance in the 1997 studies. Both were well

above the natural standard of 5 plants m-2. Timely summer rains gave May seedlings a much

needed boost to become established on overburden soils. However, conditions were too dry and

windy for wiregrass to establish on sand tails soils at either seeding date.

Indiangrass established relatively well on both soil types on both dates. It was especially able to

take advantage of summer rains to become established on overburden soils. Lopsided

Indiangrass is a very good candidate for use in a native seed mix for reseeding critical area sites.

It established relatively well on all soil types despite severe conditions. It may not persist on all
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

267

sites, but may be an effective native “nurse crop” to help other species such as wiregrass become

established.

Table 9. Average plant densities of wiregrass and Indiangrass broadcast in January and May of

1999 on overburden and sand tails soils at 1 year and 6 months after planting respectively.

Treatment Overburden Sand Tails

Plants m-2

Indiangrass – January 107b* 21a*

Indiangrass – May 236a 30a

Wiregrass - January 15c 0.3b

Wiregrass - May 10c 0b

 *treatment means followed by different letters are significantly different by Tukey’s HSD at

P≤0.05

Conclusions

Based on this series of studies, broadcasting generally produced the highest plant densities for all

species whether planted alone or in a mixture. Lopsided Indiangrass established fairly well in

drilled treatments. Drilling with a chaffy seed drill may be advantageous for planting this species

if seed is adequately debearded. Drilling generally requires lower seeding rates, which can

reduce seed costs substantially.

Optimum broadcast seeding rate levels for Indiangrass were found to be 430 pls m-2 (40 pls ft-2)

on sand tails and overburden soils in this study. Drill seeding rates were not precisely

determined. Typically, seeding rates for drilling are half of broadcast rates. Further research will

be needed to verify this for Indiangrass. Initial studies did indicate doubling the seeding rate to

broadcast levels did not significantly increase seedling densities.

Optimum wiregrass broadcast seeding rates could not be established in these studies. Rainfall

and weed competition had a profound effect on wiregrass seedling establishment. Wiregrass

could not establish in extremely harsh conditions regardless of the seeding rate. When

conditions were favorable broadcast rates of 640 to 860 pls m-2 (60 to 80 pls ft-2) produced

adequate stands on both soil types.

References

Bissett, N.J. 1995. Upland restoration challenge: Direct seeding of wiregrass and associated

species. The Palmetto. Summer, pp 8-11.

Clewell, A.F. 1989. Natural history of wiregrass (Aristida stricta Michx., Gramineae). Nat. Areas J.

9:223-233.

Cook, C.W., R.M. Hyde, and P.L. Sims. 1974. Guidelines for revegetation and stabilization of

surface mined areas. Colo. St. Univ., Range Sci. Dep. Sci. Ser. No. 16. Fort Collins, Colo.

MSTAT-C. 1983. Michigan State University.

Pfaff, S. and M.A. Gonter. 1996. Florida Native Plant Collection, Production and Direct Seeding

Techniques: Interim Report. USDA NRCS, Brooksville, FL and FL Inst. of Phosphate Res.

Bartow, FL pp 48-56.

Seamon, Greg. 1998. A longleaf pine sandhill restoration in northwest Florida. Restoration &

Management Notes. 16:1 Summer 1998. pp.46-50.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

268

Increasing Establishment Success of Native Grasses -- Matching the

Techniques with the Equipment

Larry Pollard1

Abstract

My presentation will stress features of grass and wildflower planting equipment. Native grass

seed is expensive, whether purchased directly or accumulated through labor intensive harvest

methods. Reducing the risk of establishment failure is important to individuals, consultant clients

or answering to organizational management. Quality viable seed at planting time, using adapted

ecotypes, site preparation, timing, weed control, favorable weather, and knowledge of planting

techniques will not complete the job. Reliable equipment, designed to achieve the desired seed

placement, seed depth, seed rate and that all-important seed to soil contract is key to those job

specs. Then, someone still has to operate that equipment.

 

1 Marketing Representative, Truax Company, Inc., 4821 Xerxes Ave. N., Minneapolis, MN 55430
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

269

Comparative Biomass, Composition, and Forage Quality of

Greenhouse-grown Gamagrass Plants Differing in Age,

Stage of Development, and Drought Tolerance

James B. Reeves, III1, Donald T. Krizek2, Charles D. Foy2, and Jerry C. Ritchie3

Abstract

The primary objective of this work was to evaluate the biomass, composition, and forage quality

of eastern gamagrass [Tripsacum dactyloides (L.) L.] differing in age, stage of development, and

drought tolerance. Young plants were established in the greenhouse from seed. Also 2-year old

plants selected from field plots for drought tolerance (DT) or drought sensitivity (DS) in Nov 1997

were transplanted into the greenhouse. Six samples of 15 young plants each were cut back to 25

cm at 80, 94, 108, 122, 147, 164, and 185 days from seeding. Three DT and three DS plants

each were treated as above with regrowth harvested at 94, 108, and 122 days. Samples from

each harvest were analyzed for neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin,

and crude protein (CP). The Least Significant Difference test was used to evaluate differences in

composition, biomass, and drought tolerance over time. While little variation in NDF with age was

found in young plants, DS plants had significantly higher NDF than DT plants regardless of age.

Greater variations were found for ADF, lignin, and CP with age for young plants and for ADF, but

not for lignin or CP, for the DT and DS plants. Also, DT plants generally had lower lignin content

than DS plants regardless of age. Finally, biomass for young plants differed significantly with

age, increasing to day 218, then decreasing. Biomass of DS plants was generally greater than

DT plants of the same age. These results show that gamagrass displays complex variations in

composition and thus forage quality during aging and in selected genotypes differing in drought

tolerance. Overall, forage quality was excellent with CP ranging from 15-18%. Plants were also

high in fiber with NDF, ADF, and lignin ranging from 77-85%, 38-43%, and 2.9 to 4.7%,

respectively.

 

1 Nutrient Metabolism and Conservation Laboratory, LPSI, ARS, USDA, Beltsville, MD, 2

Climate

Stress Laboratory, NRI, ARS, USDA, Beltsville, MD, 3

Hydrology Laboratory, NRI, ARS, USDA,

Beltsville, MD
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

270

Vegetative Propagation of Eastern Gamagrass: Effects of Root Pruning and

Growth Media

Errol G. Rhoden1, Jerry C. Ritchie2, Donald T. Krizek3 and Charles D. Foy3

Abstract

Eastern gamagrass [Tripsacum dactyloides (L.) L.] is currently being investigated as an

alternative forage crop as well as a grass hedge against erosion. Methods of vegetatively

propagating this crop are being explored in order to obtain cloned planting material. A 16-week

greenhouse study (07/31/98-11/30/98) was conducted at the Agricultural Research Service

facilities in Beltsville, MD to determine the minimal number of roots and the type of growth media

needed for the successful propagation of ‘Pete’ eastern gamagrass. The treatments consisted of

four growth media (Jiffy mix, a composted soil, Tatum clay loam and Turface) as the main effect,

and severity of root pruning (one, two, three or four roots remaining on the culm) as sub-plot in a

split plot design with three replicates. Overall, plant survival rate ranged from 16.7% in the

composted soil to 75.0% for Tatum clay loam. Of those plants surviving the transplant process,

tiller number, plant height, and foliage dry weights were greatest for plants grown in Jiffy mix.

Foliage dry weights for plants grown in Tatum clay loam, Turface, composted soil and Jiffy mix

averaged 3.9, 12.3, 23.8 and 34.2 g/plant, respectively. Root dry weight averaged 1.9 g/plant for

Tatum clay loam to 13.4 g/plant for Jiffy mix. Shoot-root ratio ranged from 3.6 in Turface to 1.7

for plants grown in composted soil. The number of roots left on the transplanted culms had no

effect on the shoot-root ratio of eastern gamagrass. Although eastern gamagrass plants grown in

Tatum clay loam had the highest survival rates, these plants were the shortest, had the lowest

plant dry weights, and the fewest number of tillers. After 16 weeks, plants obtained from culms

with 2 or 3 roots transplanted into Jiffy mix had the overall best appearance of all root

pruning/growth media treatments. It is feasible to vegetatively increase eastern gamagrass by

transplanting a minimum of crown tissue into a porous, well-aerated growth medium.

Introduction

Due to the demand to use lands currently cropped that produce limited returns, eastern

gamagrass [Tripsacum dactyloides (L.) L.] is being considered as an alternative in the

southeastern United States as a grass barrier and forage crop. This has led soil and crop

scientists to develop methods to propagate eastern gamagrass (Ahring and Frank 1968). As

information is gathered, this will help us to improve the management of existing fields of eastern

gamagrass and eventually increase the total acreage under cultivation. Advances resulting from

such research would aid in the choices we could offer in eastern gamagrass propagation.

The plant root system is most noted for playing a major role in plant growth and development.

The most important consideration that is ascribed to roots is absorbing moisture and nutrients.

The other role that roots play in plant development is to provide mechanical support from seedling

to maturity. Evans and Wardlaw (1976) have noted the role of roots in the synthesis of growth

substances such as cytokinins, considered important in leaf functions and therefore, this may

impact the propagation of eastern gamagrass. It is widely held that if plant roots do not proliferate

abundantly in the rooting medium it might affect the plant’s ability to absorb moisture and

nutrients. Therefore, any factor that diminishes root development reduces the survival potential of

the plants being propagated.

 

1

G. W. Carver Agricultural Experiment Station, Tuskegee University, Tuskegee, AL 36088;

2

Hydrology Laboratory, NRI, ARS, USDA, Beltsville, MD 20705; 3Climate Stress Laboratory, NRI,

ARS, USDA, Beltsville, MD 20705.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

271

A study of the interaction between roots and tillers is critical to the propagation process. Klepper

et al. (1984) stated that cereals do not develop nodal roots until about two or three leaves have

been formed. Belford et al. (1987) have noted that tiller roots would not develop and tillers do not

provide the hormonal control necessary for root survival. Therefore, a delay in the initiation and

development of root tissue during propagation would prevent tiller development and would

ultimately impact plant survival.

One accession of eastern gamagrass (PMK 24) obtained as a composite from several collections

found in Kansas and Oklahoma was released as ‘Pete’ (Fine et al. 1990). Foy (1997; 1999)

working with a Tatum clay loam soil (fine kaolinitic, mixed, thermic typic hapludult) noted that

eastern gamagrass was very tolerant of this highly acidic soil. Based on other work done by

Rhoden et al. (1999a), rooting media studies should include an acidic soil because of the plants

ability to grow under such high aluminum concentrations. Growth media must also be considered

as propagation tools if wide-scale cultivation of eastern gamagrass is to be realized. A

combination or modification of growth media currently available on the market might be effective

for successful propagation.

Based on low germination rates of eastern gamagrass, these researchers needed a method to

establish fields that have evenly-spaced cloned materials. Therefore, the following objectives

were developed: 1) determine the effectiveness of commonly available growth media on the

propagation of eastern gamagrass; 2) determine the effect of root pruning on eastern gamagrass

survival; and 3) determine the effect of media and root pruning on eastern gamagrass growth

and development.

Materials and Methods

This study was conducted in the greenhouse of the ARS research facilities in Beltsville, MD for 16

weeks (07/31/98 to 11/30/98). Single culms of eastern gamagrass were planted in 23-cm

diameter pots containing different growth media on July 31, 1998 and the experiment was

terminated on November 30, 1998. After planting, each pot was supplied with 250 ml of half

strength Hoagland’s solution. Thereafter, plants were watered daily or as needed and supplied

with a solution of 20-20-20 (NPK) each week. The growth conditions in the greenhouse were

maintained at a temperature of 30/25°C (day/night).

Growth Media

Four growth media of contrasting water holding capacities and bulk densities were used in this

study. The growth media were arranged as main effects in a split plot design. The growth media

were:

1) Jiffy mix (peat-lite mix);

2) Turface (Arcillite - a blend of illite, montmorillinite and silica);

3) Tatum clay loam soil (fine, kaolinitic, mixed, thermic, Typic, Hapludult);

4) A composted soil (containing peat and perlite).

The cultivar used in this study was ‘Pete’ eastern gamagrass. The culms were obtained from

material grown in the greenhouse in Jiffy mix (February to July). Plants from which propagation

material was procured averaged 24 tillers. They were washed free of Jiffy mix and separated into

single culms making sure that roots were left intact and placed in water until time of transplanting.

Roots were trimmed to a length of 10-cm. At planting, culms and roots were placed in an upright

position, thus ensuring that both crowns and roots were below the growth media surface. Live

plants were counted on August 20,1998, and survival percentage determined.

The experiment was terminated after 16 weeks (11/30/98) and biomass harvested. Plants were

washed free of growth media, blotted, separated into foliage and roots, placed into separate

paper sacks, and dried to a constant weight (70°C for 72 hours).
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272

Data were collected on a) plant height, b) tiller number, c) foliage dry weight, and d) root dry

weight. Data were subjected to Analysis of Variance and the Least Significant Difference test

(P<0.05) used to separate mean differences where applicable.

Results and Discussion

Establishment using single culms of eastern gamagrass was significantly impacted by both

growth media and number of roots remaining on the transplant. The culms transplanted into

Tatum soil had an average survival rate of 75%, with Jiffy mix and Turface surviving at an

average rate of 58.3% each (Table 1). Culms transplanted into composted soil had a very poor

survival rate (16.7%). Culms with two roots and transplanted into either Tatum soil or Turface;

those with three roots in Jiffy mix, and those with four roots in Tatum soil, all had 100% survival

rates. On the other hand, culms with three or four roots and transplanted into composted soil

showed no survival. Dewald and Sims (1981) reported a 70% survival rate for eastern

gamagrass transplants during late July and a much higher survival percentage for transplants

made from December to March, as plants were coming out of dormancy. The number of roots

also affected the rate of survival. Plants with two roots on each culm averaged 67% survival.

There was no difference between plants having either one or three roots remaining on the culm at

time of transplanting. From other work conducted on root trimming of eastern gamagrass, it was

noticed that plants tended to support root growth at the expense of foliage development (Rhoden

et al. 1999b).

Table 1. Effect of root number and growth media on survival of eastern gamagrass

Growth Media

Root # Jiffy Mix Tatum Soil Turface Composted Soil Avg.

%

1 66.7 66.7 33.3 33.0 50.0

2 33.3 100.0 100.0 100.0 66.7

3 100.0 33.3 66.7 - 50.0

4 33.3 100.0 33.3 - 41.8

Avg. 58.3 75.0 58.3 16.7

Tiller number was measured as an indicator of the plants’ ability to grow in various media. The

greatest number of tillers formed on a transplanted culm was found in Jiffy mix. Culms

transplanted with one root had an average of 12.5 tillers per plant (Table 2). This trend generally

declined with an increase in roots on the transplanted culms. Culms placed in Jiffy mix averaged

the highest number of tillers (10.7/plant). Among the four growth media, those plants that

survived the transplanting process, culms with three roots had the greatest number of tillers (8.2

tillers/plant). Although plants in Tatum soil had a very high percent survival, they did not produce

many tillers.

Plants transplanted into Jiffy mix grew taller than those in all other growth media did. Culms with

two roots transplanted in Jiffy mix had an average height of 111.2 cm (Table 3). Regardless of

growth media, culms transplanted with four roots grew the least. Plants grown in Tatum soil also

remained very short (40.9 cm). It was expected that plant height would reflect the amount of

vegetation that eastern gamagrass produces. Therefore, we expect that eastern gamagrass

planted in Jiffy mix would out-produce those planted in Tatum soil.
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273

Table 2. Effect of root number and growth media on tillering of eastern gamagrass.

Growth Media

Root # Jiffy Mix Tatum Soil Turface Composted Soil LSD.05 Avg.

Tiller #/Plant

1 12.5 1.0 5.0 12.0 2.6 7.3

2 9.0 2.0 4.0 6.0 2.2 4.1

3 11.0 1.0 7.5 - 2.7 8.2

4 8.0 2.3 3.0 - 2.9 3.6

LSD.05 2.8 1.2 1.6 4.4

Avg. 10.7 1.8 5.0 9.0

Table 3. Effect of root number and growth media on stem elongation in eastern gamagrass

Growth Media

Root # Jiffy Mix Tatum Soil Turface Composted Soil LSD.05 Avg.

Plant Height (cm)

1 99.2 38.8 98.3 95.4 18.7 78.3

2 111.2 44.4 84.3 102.1 16.3 75.0

3 99.0 21.6 78.7 - 20.4 79.3

4 59.3 45.4 95.3 - 19.8 58.2

LSD.05 14.7 9.3 8.8 NS

Avg. 95.2 40.9 86.3 98.8

The number of roots significantly impacted foliage development. Culms transplanted with three

roots produced an average of 21.3g of foliage dry matter per plant (Table 4). There were

significant differences in foliage dry weight among the growth media used in the vegetative

propagation of eastern gamagrass. Dry matter of plants transplanted into Tatum soil averaged

almost thirteen-fold less than those grown in Jiffy mix with the greatest difference in clums

transplanted with one root. Plants in Jiffy mix averaged 18.6 times the dry matter production as

those grown in Tatum soil.

Table 4. Effect of root number and growth media on foliage dry weight of eastern gamagrass

Growth Media

Root # Jiffy Mix Tatum Soil Turface Composted Soil Avg.

Foliage dry weight (g/plant)

1 41.5 2.2 8.1 17.5 18.8

2 44.4 4.8 9.9 30.0 14.4

3 33.4 2.6 12.5 - 21.3

4 11.1 5.9 23.4 - 10.4

Avg. 34.1 3.9 12.3 23.8

Root dry weight followed a similar trend to that of foliage dry weight. Plants transplanted with

three roots from each treatment had the greatest root dry weight (Table 5). Roots of plants grown

in Tatum soil had the least dry weight, followed by those transplanted in Turface. Those plants

that survived on composted soil averaged the greatest root dry weight (15.1 g/plant).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

274

Table 5. Effect of root number and growth media on root weight of eastern gamagrass.

Growth Media

Root # Jiffy Mix Tatum Soil Turface Composted Soil Avg.

Root wt.(g/plant)

1 13.4 0.7 2.8 17.6 8.1

2 14.4 1.7 2.8 12.6 5.1

3 16.7 1.1 4.2 - 9.9

4 2.5 3.2 7.2 - 3.8

Avg. 13.4 1.9 3.9 15.1

There was no significant difference in shoot:root ratio of eastern gamagrass regardless of the

number of roots that were left on the culms during the transplanting process (Table 6). However,

plants transplanted into Turface and Jiffy mix had the highest shoot:root ratios. One factor that

might influence such shoot:root ratios among the growth media is the type and amount of root

present. Roots of eastern gamagrass in the Tatum soil had an extensive mass of fibrous roots

compared to a few large nodal roots seen on the plants in the Jiffy mix and Turface.

Table 6. Effect of root number and growth media on shoot-root ratio of eastern gamagrass.

Growth Media

Root # Jiffy Mix Tatum Soil Turface Composted Soil LSD.05 Avg.

Shoot:root ratio

1 3.1 3.3 2.9 1.0 2.1 2.8

2 3.1 2.1 4.2 2.4 1.7 3.0

3 2.6 2.3 3.2 - 2.3 2.8

4 4.5 2.1 3.3 - 2.9 2.8

LSD.05 1.7 NS NS 1.6

Avg. 3.1 2.4 3.6 1.7

Conclusion

It is critical that we establish methods of propagation that will enhance the distribution of eastern

gamagrass. Vegetative development, including tillering, is an important aspect in the production

equation. Therefore, management practices, including growth media, used in the vegetative

propagation process will impact culm survival and tillering. It is also important to consider the

number of roots that remain on the culm during the propagation process.

Using vegetative propagation in the establishment of eastern gamagrass might be an effective

tool in producing large numbers of genetically identical plants. If we look at tiller number as an

indicator of a plants’ ability to develop after rooting, then Jiffy mix and Turface appear to be

excellent media in achieving rapid development. However, Tatum soil, which is very acid and

adheres to the culms, had excellent survival rates of plants. Therefore, methods that combine

both media, or development of a medium that gives those qualities should be explored.

It would appear that the chances of successful survival of propagated material lie in the rapid

development of roots on both the propagated culm and the successive tillers. Factors such as

the carbohydrate reserves of the transplanted culm as well as temperature, nutrient status, and

moisture will affect the successful survival of the propagated material. Coupled with the rate of
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

275

vegetative propagated material survival, is the need to develop equipment that can easily plant

these materials in the field. Without such equipment, large-scale vegetative propagation would

not be a successful tool to increase eastern gamagrass acreage.

References

Ahring, R.M. and H. Frank. 1968. Establishment of eastern gamagrass from seeds and vegetative

propagation. J. Range Manage. 21:27-30.

Belford, R.K, E.L. Klepper, and R.W. Rickman. 1987. Studies of intact shoot-root systems of fieldgrown winter wheat. 2. Root and shoot developmental patterns as related to nitrogen fertilizer.

Agron. J. 79(2):310-319.

Dewald. C.L. and P.L. Sims. 1981. Seasonal vegetative establishment and shoot reserves of

eastern gamagrass. J. Range Manage. 34(4):300-304.

Evans, L.T. and I.F. Wardlaw. 1976. Aspects of the comparative physiology of grain yield in

cereals. Adv. Agron. 28:301-359.

Fine, C.L., F.L. Barnett, K.L. Anderson, R.D. Lippert, and E.T. Jacobson. 1990. Registration of

‘Pete’ eastern gamagrass. Crop Sci. 30(3):741-742

Foy C.D. 1997. Tolerance of eastern gamagrass to excess aluminum in acid soil and nutrient

solution . J. Plant Nutrition. 20(9):1119–1136.

Foy, C.D., A.M. Sadeghi, J.C. Ritchie, D.T. Krizek, J.R. Davis, and W.D. Kemper. 1999.

Aluminum toxicity and high bulk density: Role in limiting shoot and growth of selected aluminum

indicator plants and eastern gamagrass in an acid soil. J. Plant. Nutri. 22(10):1551-1566.

Klepper, B., R.K. Belford, and R.W. Rickman. 1984. Root and shoot development in winter wheat.

Agron. J. 76(1):117-122.

Rhoden, E.G., J.C. Ritchie, D.T. Krizek, and C.D. Foy. 1999a. Root distribution of eastern

gamagrass in acid soil. Agron. Abstract 91:285.

Rhoden, E.G., J.B. Reeves, J.C. Ritchie, and D.T. Krizek. 2000. Influence of root removal on

regrowth and forage quality of greenhouse-grown eastern gamagrass. Proceedings of the

Second Eastern Native Grass Symposium, Baltimore, MD. (This Volume)
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

276

Influence of Root Removal on Shoot Regrowth and Forage Quality of

Greenhouse-Grown Eastern Gamagrass

Errol G. Rhoden1, James B. Reeves, III2, Donald Krizek3, Jerry C. Ritchie4, and Charles D. Foy3

Abstract

This study was conducted to determine the influence of root removal on shoot regrowth,

composition, and forage quality of greenhouse-grown eastern gamagrass plants. On 27 July

1998, the root mass of 5-month old plants was pruned 25% or 50%, or left uncut and the plants

were transferred to 20-cm diameter pots having a depth of 40 cm. Plants were grown in a peatvermiculite mix and fertilized weekly. Shoots were clipped to 25 cm on 18 August (H1), 16

September (H2), 7 October (H3), and 28 October (H4). For each harvest, height and total

biomass measurements were taken on shoot regrowth and samples were analyzed for neutral

detergent fiber (NDF), acid detergent fiber (ADF), lignin, crude protein (CP), dry matter

digestibility (DMD), and cell wall digestibility (CWD). Plants were vegetative at H1 and H2, in

flower by H3, and starting to become dormant by H4. Trimming roots of eastern gamagrass

plants at the time of transplanting had a negative effect on subsequent regrowth of shoots,

particularly when 50% of the roots were removed. This was generally reflected in an increase in

the number of senescent leaves, a decrease in the number of tillers and in a reduction in the dry

weight of forage collected. Despite these reductions in vegetative growth, there was little or no

effect of root removal or date of harvest on forage composition or quality. Root removal had no

significant effect on NDF or ADF and little or no effect on DMD or CWD at H1-H4. Content of

lignin and CP was variable, depending on the extent of root removal and the date of harvest. CP

content of the forage samples ranged from 14% to nearly 20% which is higher than that typically

reported for field-grown eastern gamagrass plants. The ability of eastern gamagrass plants to

cope with the stress of root pruning without altering the quality of forage demonstrates the

resilience of this species for adapting to adverse environmental conditions.

Introduction

Eastern gamagrass [Tripsacum dactyloides (L) L.] is a warm-season perennial bunchgrass that is

recognized as a highly productive and palatable forage crop (Bidlack et al. 1999). Although it was

a very popular forage in 19th century America (Magoffin, 1843), through overgrazing and

advanced plow technology it all but disappeared as a forage species. Currently, it is regaining

some of its prominence. Brejda et al. (1994; 1996) have looked at its use as silage using different

nitrogen rates. Dickerson and van der Grinten (1990) have recommended it as an excellent crop

for halage in the northeast.

Eastern gamagrass is a monoecious grass with morphology similar to corn. It is a long-lived

perennial that is well adapted to a wide range of growing conditions (Faix et al., 1980). Hitchcock

and Chase (1971) along with Harlan and DeWet (1977) have cataloged its range from the Atlantic

Coast to the Rockies in North America, to Bolivia and Paraguay in South America. Due to its

versatility and its range of adaptation, eastern gamagrass is ideally suited for a wide range of

agricultural uses. Eastern gamagrass has been found to send its roots through compact soils

(McGinty and Alberts, 1995; Rhoden et al., 1999). Not only is the plant capable of penetrating

hardpans and claypans, it also tolerates high levels of aluminum as shown both in the

greenhouse, using an acidic, Al toxic soil or nutrient solution and in the field using an acidic, Al

toxic soil (Foy, 1997; Foy et al., 1999). Furthermore, eastern gamagrass, because of its ability to

 

1

George Washington Carver Agricultural Experimental Station, Tuskegee University, Tuskegee,

AL 36088; 2

Nutrient Metabolism and Conservation Laboratory, LPSI, ARS, USDA, Beltsville, MD

20705; 3

Climate Stress Laboratory, NRI, ARS, USDA, Beltsville, MD 20705, 4Hydrology

Laboratory, NRI, ARS, USDA, Beltsville, MD 20705
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

277

penetrate compact subsoil, provides root channels for subsequent crops (McGinty and Alberts,

1985; Alberts et al., 1996; Clark et al., 1998). Ritchie et al. (1997) have used it as a grass hedge

for erosion control. While it is commended for its role in sustainable agricultural production, it

also deserves praise for its high yield, protein content, digestibility, and palatability (Faix et al.,

1980; Burns et al., 1992; Surrency et al., 1998). These researchers have recommended that the

grass be grazed or clipped to a height of 25-40 cm and have found that it contains as high as

17% crude protein and total digestible nutrients of 65%. This has resulted in impressive steer

gains (Aiken, 1977). Horner et al. (1985) and Cherney et al. (1994) have compared eastern

gamagrass to alfalfa with good results. This makes eastern gamagrass an ideal candidate for

further studies in the southeastern United States.

The response of eastern gamagrass to environmental and physiological stresses is thoroughly

documented. Root trimming and growth media have been shown to influence shoot production in

eastern gamagrass (Rhoden et al., 2000). Factors controlling shoot development are not fully

understood but are linked to the ability of the plant to effectively utilize its carbohydrate, nutrient,

and water supply. Roots contribute to the uptake of nutrients and water which in turn influence

the survival of the plant. Klepper et al. (1984) have shown that root and shoot development are

intrinsically connected with one another. Roots are believed to exert hormonal control and

ultimately determine shoot morphogenesis. Belford et al. (1987) have postulated that the number

and length of roots are important in determining whether a tiller aborts or survives on the parent

plant under field conditions. In another study, Belford et al. (1986) were able to influence root

length and initiation by increasing fertility during various stages of plant development.

The objective of this study was to determine shoot regrowth, composition, and forage quality of

eastern gamagrass after initial removal of 0, 25% and 50% of its root system.

Materials and Methods

This study was conducted in a Climate Stress Laboratory greenhouse at ARS research facilities

in Beltsville, MD for 16 weeks (27 July to 28 Oct 1998). Seeds of ‘Pete’ eastern gamagrass were

placed in germination trays containing a peat-vermiculite mix (Jiffy mix) in the greenhouse on 20

March 1998 and growth was carefully monitored. Seedlings were selected for uniformity, and

transplanted to 10-cm diameter plastic pots on 6 April and then to 15-cm diameter pots on 19

May. On 27 July 1998, plants were removed from the 15-cm pots and plant roots pruned 25% or

50%, or left intact. These three treatments were replicated three times in a complete randomized

design.

Following treatment, the plants were transferred to 20-cm diameter pots of peat-lite mix having a

depth of 40 cm and fertilized with 250 ml of half strength Hoagland’s solution. Thereafter, plants

were watered daily or as needed and supplied with a solution of 20-20-20 (NPK) each week. The

growth conditions in the greenhouse were maintained at a day/night temperature of 30/25°C. The

tops of eastern gamagrass plants were clipped to 25 cm on 18 August (H1), 16 September (H2),

7 October (H3) and 28 October (H4) as shown in Table 1. Plants from the first three harvests

were in a vigorous stage of growth; however, by the third harvest plants were flowering (Table 1)

and by the fourth harvest, all plants were starting to show signs of dormancy.

Data on number of tillers and number of senescent leaves were collected for the first two

harvests. Data on the amount of shoot regrowth based on linear measurements and biomass

were collected at all four harvests but are only presented for H1 and H2. Samples for forage

composition and quality were taken at all four harvests and dried in a forced draft oven at 70o

C

for at least 72 hr. Analyses from each treatment at each harvest were run in duplicate for crude

protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, cell wall digestibility

(CWD), and dry matter digestibility (DMD) using the method of Goering and Van Soest (1970).

The NDF was determined by boiling 1 g of the forage sample in a neutral detergent solution (pH

7.0), 2 ml decanaphthalene, and 0.5 g of sodium nitrite. This was left to reflux for 60 minutes.

Contents were then filtered into a crucible and solids washed twice with hot water (90o

C) and
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

278

twice with acetone. Crucibles were then dried at 100o

C overnight and weighed. NDF was

calculated as a percentage of the original dry weight of the forage sample. Acid detergent fiber

was determined in the same manner except that an acid detergent solution (pH 2.0) was used.

Lignin was determined by digesting the ADF in 72% H2SO4 at 15o C for 3 hours and filtering. The

residue was washed, dried, and ashed at 550o

C for 12 hours. The loss in weight during ashing

approximated the content of lignin present. Crude protein was determined by using the macroKjeldahl procedure. Data were subjected to Analysis of Variance and the Least Significant

Difference test (P<0.05) used to separate mean differences where applicable.

Table 1. Harvest dates, condition, and stage of development of eastern gamagrass plants grown

in the greenhouse in root removal study.

Harvest Number Harvest Date Plant Condition Stage of Development

H1 18 Aug 1998 Vigorous Vegetative

H2 16 Sept 1998 Vigorous Vegetative

H3 7 Oct 1998 Vigorous Flowering

H4 28 Oct 1998 Onset of dormancy Flowering

Results and Discussion

There were no significant differences in the heights of regrowth of eastern gamagrass plants

among any of the treatments at H1 although plants with roots cut back initially 25% appeared to

show a slight stimulation in linear regrowth as compared to the other treatments (Table 2).

Removal of 25% of the roots caused a 43% increase in the number of senescent leaves while

removal of 50% of the roots caused a 135% increase in the number of senescent leaves. This is

important to note as roots of all plants were observed emerging through the mesh at the bottom

of the 40-cm deep pots in 10 days, including those cut back initially by 50%. Thus, the plants

seem to have diverted some of their reserves from the leaves to the roots. The number of tillers

was also significantly reduced by root trimming. Removing 25% of the roots at transplanting

caused an average 26% reduction in the number of tillers produced while removing 50% of the

roots caused an average 43% reduction in the number of tillers, as compared to unpruned

controls at H1. Although removal of 25% of the roots had no effect on the average amount of

forage dry matter produced at H1, removal of 50% of the roots reduced the average amount of

forage dry matter by 41%.

Table 2. Effect of percent root removal on shoot regrowth, number of senescent leaves, number

of tillers and forage dry weight (DW) of eastern gamagrass plants maintained in the greenhouse

(1st Harvest).

Shoot Regrowth Senescent Leaves Tillers Dry Weight

Forage

Root Removal

%

cm number g/plant

0 67.7 32.7 38.7 26.6

25 87.0 46.7 28.7 25.6

50 68.0 76.7 22.0 15.7

LSD 0.05 19.3 27.6 11.6 5.9

The trend in linear regrowth at H2 was similar to that observed at H1 with plants having roots

pruned initially 25% showing a slight stimulation in growth as compared to those left intact or

those pruned 50% (Table 3). Root pruning had a marked effect on the number of senescent

leaves produced at H2. Initial removal of 25% and 50% of the roots increased the number of
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

279

senescent leaves at H2 an average of 120% and 164%, respectively, as compared to plants with

intact roots. Tiller formation at H2 was greatly affected by root pruning and appeared to be a good

way to measure recovery of eastern gamagrass plants following root removal. Plants with roots

trimmed initially 25% had an average 14% decrease in number of tillers while those pruned 50%

had an average 52% decrease. Forage yield at H2 was also significantly impacted with plants

pruned 25% showing an average 15% decrease in dry matter and those pruned 50% showing an

average 41% reduction (Table 3).

Table 3. Effect of percent root removal on shoot regrowth, number of senescent leaves, number

of tillers and forage dry weight (DW) of eastern gamagrass plants maintained in the greenhouse

(2nd Harvest).

Shoot Regrowth Senescent Leaves Tillers Dry Weight

Forage

Root Removal

%

cm number g/plant

0 73.0 61.7 63.3 51.9

25 87.0 135.7 54.3 44.0

50 68.0 162.7 30.7 30.4

LSD 0.05 11.3 73.1 24.3 12.1

At each harvest, forage samples were taken from each root pruning treatment and analyzed to

determine forage composition and quality. NDF and ADF values showed only slight differences

between any two harvests and between any two pruning treatments and these differences were

not significant (Table 4). This is rather remarkable considering that samples were taken in the

greenhouse over a two-month period from 18 August to 28 October. Lignin content varied

considerably from harvest to harvest and among different pruning treatments. There was a

significant increase in the lignin content between H1 and H2, irrespective of whether or not the

roots were initially pruned 25% or left intact, suggesting that the shift may have been caused by

an increase in maturity rather than as a result of pruning treatment. Although the lignin content at

0 and 25% root removal appeared to decline slightly from H2 to H3, this difference was not

significant, nor were differences between H3 and H4 significant. There were no significant

differences in lignin content with date of harvest when 50% of the roots were pruned initially.

Table 4. Effect of percent root removal on neutral detergent fiber (NDF), acid detergent fiber

(ADF), and lignin content of eastern gamagrass at various harvest dates.

Percent of Root Removal

0% 25% 50% 0% 25% 50% 0% 25% 50%

Harvest

Number

NDF (% DM) ADF (% DM) Lignin (% DM)

1 81.4a 82.0a 84.3a 36.3a 36.1a 36.8a 3.3b 3.5b 3.9a

2 80.5a 80.2a 81.7a 38.2a 37.9a 38.3a 4.3a 4.3a 4.3a

3 78.9a 80.0a 81.4a 35.3a 36.7a 37.2a 3.7ab 3.8ab 4.1a

4 82.2a 82.6a 79.9a 36.0a 35.8a 37.3a 3.8ab 3.4b 3.6a

LSD 0.05 3.5 4.2 5.6 3.3 2.7 3.9 0.9 0.6 1.1

Means of any two values for a single constituent within a column having a common letter are not

significantly different at P 

The CP content of the forage samples of greenhouse-grown eastern gamagrass plants was high,

ranging in value from 14% to nearly 20%, even when flowering shoots were included as at H3

and H4. This attests to the excellent nutritive value of this species. These figures are higher than

those reported for field-grown eastern gamagrass plants by Horner et al. (1985). This may reflect
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

280

the high nutrient status under which the plants had been grown in the greenhouse (having been

fertilized weekly). A comparison of any two harvests indicated that the CP content was quite

variable, depending on the extent of root removal and on the date of harvest. Unpruned controls

had a lower CP content at H2 than at H1, H3 or H4 (Table 5). When the plants were pruned 25%,

the greatest CP content was obtained at H1 and H4 and samples at H2 and H3 were intermediate

in value. There was no significant difference in CP content of eastern gamagrass foliage between

any two harvest times when the roots of the plants were initially pruned 50% (Table 5).

Table 5. Effect of percent root removal on dry matter digestibility (DMD), cell wall digestibility

(CWD), and crude protein (CP) content of eastern gamagrass at various harvest dates.

Percent of Root Removal

0% 25% 50% 0% 25% 50% 0% 25% 50%

Harvest

Number

DMD (% DM) CWD (% DM) CP (% DM)

1 80.7a 81.6a 79.2ab 74.3a 75.7a 73.5ab 17.3a 19.6a 18.1a

2 78.2a 76.7b 75.7b 71.0a 69.0b 68.2b 13.6b 14.3c 16.2a

3 80.5a 81.1a 82.2a 73.8a 75.3a 76.8a 16.8a 16.5b 18.6a

4 79.9a 81.4a 81.9a 73.9a 76.1a 76.0a 17.9a 18.4a 17.9a

LSD 0.05 4.0 3.8 4.5 5.5 5.1 5.8 2.4 1.3 4.8

Means of any two values for a single constituent within a column having a common letter are not

significantly different at P 

The CP content was significantly lower at H2 than at H1 in unpruned controls and in those pruned

25%. In both cases, the content of CP and lignin showed an inverse relationship with lignin

content increasing and CP content decreasing from H1 (Tables 4 and 5). The highest CP

contents were obtained at H1 and H4 despite the fact that plants at H4 were at the onset of

dormancy.

There was no change in DMD at successive harvests when the roots were left intact. However,

when the roots were pruned 25%, forage samples at H2 were significantly lower in DMD than

those taken at H1 and there was a recovery in DMD at H3 and H4. Similar results were obtained

when the roots were pruned 50%. Cell wall digestibility showed a similar pattern with a decrease

during H2 in plants that had been pruned 25% followed by an increase during H3 and H4. Since

forage samples taken at H3 and H4 included flowering shoots, one might have expected that

these samples would have had a greater lignin content and a lower DMD and CWD than those

collected of vegetative shoots at H1 and H2. However, this was not the case (Tables 4 and 5).

Bidlack et al. (1999) have also reported on the variability of CP and lignin content in the leaves

and stems of several eastern gamagrass lines established vegetatively in the field in 1991 and

harvested in 1992 and 1995. It has been suggested that lignin has a detrimental effect on the

digestibility of grasses (Church 1977). Van Soest (1965) reported a negative correlation between

digestibility and increasing lignin and ADF and Bidlack et al. (1999) also found a significant

negative correlation between in vitro dry matter digestibility and lignin concentration.

Conclusion

Trimming roots of eastern gamagrass plants at the time of transplanting had a negative effect on

subsequent regrowth of shoots, particularly when 50% of the roots were removed. This was

generally reflected in an increase in the number of senescent leaves, a decrease in the number of

tillers, and a reduction in the dry weight of forage collected during the first two harvests. Despite

these reductions in vegetative growth, there was little or no effect of root removal or time of

harvest on forage composition or quality. A slight increase in lignin content and slight decreases

in CP, DMD, and CWD were obtained at H2 in plants that had been pruned 25% but these

constituents tended to show a reversal in values at subsequent harvests. Removal of 50% of the
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

281

roots surprisingly had little or no significant effect on CP or lignin content. It appears that one of

the main ways in which eastern gamagrass plants coped with the stress of root pruning was to

increase the number of senescent leaves. This is rather remarkable considering that these stress

effects were not reflected in a decline of forage quality of the new shoots formed. These findings

demonstrate the extreme versatility of eastern gamagrass in coping with environmental stress

and in being able to compensate for adverse growth conditions.

Acknowledgements

Grateful acknowledgements are extended to Miguel McCloud, Climate Stress Laboratory for his

valuable assistance in maintaining the eastern gamagrass plants in the greenhouse and for

collecting, drying, and grinding forage samples; Louis Rose for his careful monitoring of

environmental conditions in the greenhouse; and Roman Mirecki for his expert computer

assistance. Partial funding provided by USDA Competitive Research Grant awarded to Donald

Krizek.

References

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gamagrass grazed continuously for different durations. J. Animal Sci. 75(3):803-808.

Alberts, E.E., W.D. Kemper, R.L. Raper, and R.B. Clark. 1996. Impact of eastern gamagrass on

hydraulic and strength properties of claypan soils. In: Abstr. Int. Soc. Root Research, 5th Symp.

(14-18 July 1996, Clemson, SC). p. 87. Clemson Univ., Clemson, SC.

Belford, R.K., R.W. Rickman, B. Klepper, and R.R. Almarras. 1986. Studies of intact shoot-root

systems of field-grown winter wheat. 1. Sampling techniques. Agron. J. 78(5):757-760.

Belford, R.K., B. Klepper, and R.W. Rickman. 1987. Studies of intact shoot-root systems of fieldgrown winter wheat. 2. Root and shoot developmental patterns as related to nitrogen fertilizer.

Agron. J. 79(2):310-319.

Bidlack, J.E., J.E. Vaughan, and C.L. Dewald. 1999. Forage quality of 10 eastern gamagrass

[Tripsacum dactyloides (L.) L.] genotypes. J. Range Manage. 52(6):661-665.

Brejda, J.J., J.R. Brown, J.M. Asplund, T.E. Lorenz, J.L. Reid, and J. Henry. 1994. Eastern

gamagrass silage fermentation characteristics and quality under different nitrogen rates. J. Prod.

Agric. 7(4):477-482.

Brejda, J.J., J.R. Brown, T.E. Lorenz, J. Henry, J.L. Reid, and S.R. Lowry. 1996. Eastern

gamagrass responses to different harvest intervals and nitrogen rates in northern Missouri. J.

Prod. Agric. 9(1):130-135.

Burns, J.C., D.S. Fisher, K.R. Pond, and D.H. Timothy. 1992. Diet characteristics, digesta

kinetics, and dry matter intake of steers grazing eastern gamagrass. J. Animal Sci. 70(4):1251-

1261.

Cherney, J.H., J.R. Cherney, D.G. Fox, L.E. Chase, and P.J. Van Soest. 1994. Evaluating

forages for dairy cattle. Proc. American Forage and Grassland Council. 50:207.

Church, D.C. 1977. Livestock Feeds and Feeding. O and B Books, Inc., Corvallis, OR.

Clark, R.B., E.E. Alberts, R.W. Zobel, T.R. Sinclair, M.S. Miller, W.D. Kemper, and C.D. Foy.

1998. Eastern gamagrass (Tripsacum dactyloides) root penetration into and chemical properties

of claypan soils. Plant Soil 200(1):33-45.
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Dickerson, J.A. and M. van der Grinten. 1990. Developing eastern gamagrass as a haylage crop

for the Northeast. Proc. Amer. Forage Grassland Conf., Belleville, PA. pp. 194-198.

Faix, J.J., C.J. Kaiser, and F.C. Hinds. 1980. Quality, yield, and survival of Asiatic bluestems and

an eastern gamagrass in southern Illinois. J. Range Manage. 33(5):388-390.

Foy, C.D. 1997. Tolerance of eastern gamagrass to excess aluminum in acid soil and nutrient

solution. J. Plant Nutri. 20(9):1119-1136.

Foy, C.D., A.M. Sadeghi, J.C. Ritchie, D.T. Krizek, J.R. Davis, and W.D. Kemper. 1999.

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Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

283

Grass Hedges for Erosion Control

Jerry C. Ritchie1, W. Doral Kemper2, John M. Englert3 and Donald T. Krizek4

Abstract

Erosion is a major concern in agricultural areas around the world leading to soil loss, reduced soil

productivity, and downstream offsite pollution. Grass hedges are widely used in the tropics to

reduce soil loss, but few studies have produced quantitative data on these conservation

practices. In studies at Beltsville, Maryland miscanthus [Miscanthus sinensis Andersson] and

eastern gamagrass [Tripsacum dactyloides (L.) L] were used to establish grass hedges on the

contour across swale areas. Quantitative data from these studies show that these narrow, stiff

grass hedges act as filters to slow and broaden the water flow area, resulting in ponding that

increases settling times for entrained material to be deposited in the low areas. Deposition rates

measured using field surveys in 1991, 1995, and 1998 were 1-2 cm yr-1 up slope from these

hedges. These deposition areas in the swales further reduced the steepness of the slopes giving

even larger areas for the water to spread and slow. Grass hedges can be an alternative

conservation practice for reducing soil loss and dispersing runoff from areas of erosion in

agricultural fields. However, grass hedges should not be seen as a panacea, but as another tool

in the arsenal to control soil loss and runoff. Continued efforts to control soil loss at the point of

detachment are critical. The NRCS has developed a Conservation Practice Standard for using

grass hedges for runoff and sediment control. While miscanthus is effective as a grass hedge,

indigenous grasses (i.e., eastern gamagrass, switch grass [Panicum virgatum L.]) should be used

when possible to reduce the potential for the introduction of exotic material into new

environments.

Introduction

Erosion is a major problem around the world (Brown and Wolf 1984; Morgan 1995; Pimentel et al.

1995). Concerns about this erosion have led to the development of many methods to reduce soil

loss. One such method, stiff, erect narrow grass hedges planted on the contour across swales,

has been widely used to slow runoff and reduce soil loss from agricultural areas in the tropics

(NRC 1993; Dabney et al. 1999). The United States Department of Agriculture (USDA) proposed

using grass hedges for erosion control about forty years ago but until recently there has been little

interest in the use of grass hedges in the United States (Kemper et al. 1992).

Research has shown grass hedges to reduce water erosion (Dabney et al. 1993, 1995, 1999) and

wind erosion (Aase and Pikul 1995; Siddoway 1970). Grass hedges disperse runoff, trap eroding

particles, prevent gullying (Dabney et al. 1993; Meyer et al. 1994), and enhance terrace formation

(Aase and Pikul 1995: Dabney et al. 1999). Grass hedges are an inexpensive conservation

technology compatible with many tillage systems (Dabney et al. 1993).

Grass hedges differ from other types of grass barriers (i.e., buffer strips, filter strips) because they

are narrow, planted with stiff, erect grasses, and are designed to stimulate the formation of

benches by deposited materials. A uniform stand of stiff grass stems in a hedge across

concentrated flow paths and swales, causes temporary ponding of runoff water up slope of the

hedge that allows time for entrained particles to be deposited. The deposited material fills low

places in the field so that future runoff is broadly dispersed and less erosive. Narrow grass

hedges are planted on the contour across swales in the field to slow water flow (Kemper et al.

 

1

Hydrology Laboratory, NRI, ARS, USDA, Beltsville, MD 20705, 2424 Winding Branch Drive,

Oshkosh, WI 54904, 3

National Plant Material Center, NRCS USDA, Beltsville, MD 20705,

4

Climate Stress Laboratory, NRI, ARS, USDA, Beltsville, MD 20705
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284

1992). Design, spacing, and lateral extent for hedges in swales depend on runoff rates,

topography, and other factors (Dabney et al. 1993; Kemper et al. 1992).

In 1991 the Hydrology Laboratory, Agriculture Research Service (ARS), USDA, at the Beltsville

Agricultural Research Center (BARC) in cooperation with the USDA Natural Resource

Conservation Service (NRCS), National Plant Material Center at Beltsville, MD began a program

to study the use of grass hedges to control soil loss from concentrated flow erosion areas. In

1991 shoots of miscanthus [Miscanthus sinensis Andersson] were transplanted into hedges in

agricultural fields with concentrated flow channels. In 1994 and 1995, eastern gamagrass

[Tripsacum dactyloides (L.) L.] was planted using seed at several sites with the miscanthus

hedges to extend the length and to fill gaps in the hedges.

The purpose of this study was to establish grass hedges across concentrated flow areas and to

determine the effectiveness of grass hedges for slowing concentrated flow gully development and

capturing soil moving from the field.

Methods

Miscanthus shoots were transplanted into hedges across an eroding area on the South Farm at

the BARC, Beltsville, MD (Fig. 1). This field has a history of row cropping on the contour with

alternating years of corn [Zea mays L.] and soybeans [Glycine max (L.) Merrill] on adjacent

contoured strips. Contour strips are between 36 to 40 m wide with slopes of 10 to 15%. Corn

and soybeans are no-till planted. Concentrated flow erosion areas had developed in the field.

Starting near the crest of the slope, evidence of these concentrated flow erosion areas could be

traced across three contour strips before joining near the base of the slope to exit the field. On

April 17, 1991, the miscanthus shoots were transplanted into four (4) hedges across swales and

concentrated flow erosion areas. Hedges were placed in the borders between contour strips of

crops to minimize interference with farm operations and to reduce disturbance to the hedge rows

during the field and harvest operations. The grass hedge at hedge B (Fig. 1) was destroyed

during farm operations in preparation for planting in 1992.

In 1994 and 1995 miscanthus shoots were used to fill gaps in the hedges and the length of the

existing hedge rows was extended by planting eastern gamagrass seeds. In 1994, eastern

gamagrass germinated successfully and developed robust stands. However, the eastern

gamagrass planted in 1995 did not germinate, probably due to six weeks of dry weather

immediately after the seeding.

A topographic survey at hedge A (Fig. 1) was made using conventional surveying techniques

(i.e., level and rod) in April 1991. Survey lines were made 5 cm down slope and 5 cm and 100

cm up slope of the hedge. In August 1995 and August 1998, these lines were resurveyed. The

1998 survey was expanded to make measurements at 1 m grid intervals for an area 100 x 36 m

up slope of hedge A.

A second site was chosen on the East Farm at the BARC (Fig. 2). The field had a history of

being planted in corn or soybeans. This field also had a slope of 10 to 15% with a total slope

length of about 150 m. A major concentrated flow erosion area had developed in the field. In

April 1991, a tile drain was installed in the lower part of the field in the approximate location of the

concentrated flow area between hedge A and hedge B (Fig. 2). On May 23, 1991, after the

installation of the tile drain, miscanthus shoots were transplanted into five hedge rows (A to E) in

this field. In 1991 and 1992, corn was planted after the field was conventionally tilled. After the

corn was harvested in September 1992, clover was no-till planted in the field to provide a winter

cover. Between fall and spring of 1992/1993 a conservation plan for agricultural operations on

the field was developed changing the farming practices on this field from a single field with a

slope length of 150 m to a field with five contoured strips of approximately 30 m. In March 1993,

two of the 1991 miscanthus hedges B and C were moved to hedge G and hedges D and E were

moved to hedge F to be in the borders between the new contour strips in the field. Hedge A at
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

285

the lower edge of the field was not affected. The three miscanthus hedges (A, F, and G) grew

actively during 1993 and are now well established. After the 1993 growing season, farm

operations in the field changed from row cropping to small grain/clover which continued from

1993 to 1998. In 1998 and 1999 alternate contour strips were no-till planted in corn.

Figure 1. Grass hedges at the BARC South Farm study site. Letters and boxes indicate location

of miscanthus plantings. Solid lines represent borders between strips of crops and dashed lines

represent the approximate location of concentrated flow areas (Not to scale).

Figure 2. Grass hedges at the East Farm study site. Letters and boxes indicate the location of

the miscanthus plantings in 1991 (A-E) and the new location (A, G and F) after 1993. Dashed

lines represent borders between contour strips and the approximate location of the concentrated

flow area. (Not to scale).

GRASS HEDGES STUDIES

BARC SOUTH FARM SITE

A

B

C

D

GULLY
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In 1994 and 1995 the lengths of existing hedges were extended using eastern gamagrass.

Plantings in 1994 were successful but as with the South Farm site, eastern gamagrass seeds did

not germinate in 1995. Topographic surveys were made along hedge A in 1991 and 1995. Lines

were surveyed 5 cm behind and 5 cm and 100 cm up slope of the hedge row.

Results

Miscanthus grew rapidly and expanded from the transplanted shoots. Beginning with 2-5 cm

plants transplanted 10 to 15 cm apart in 1991 and 1992, hedge A in both fields has grown to a

width of 30-50 cm and a height of 1.5 to 2.5 m. At hedge A on the South Farm field the

miscanthus was two meters tall at the end of the first (1991) growing season. Trimming half of

this hedge to 75 cm each year has not affected its growth or expansion. Miscanthus quickly put

out new growth and continues to expand after each trimming. No differences were noted in

growth between the trimmed and untrimmed portions of the hedge but a reduction of crop

production was measured adjacent to the untrimmed hedge when compared to the trimmed

hedge (Ritchie et al. 1997).

In 1994, eastern gamagrass seeds were planted to fill gaps and expand hedge lengths at both

field sites. High rates of seed germination occurred in 1994, although eastern gamagrass is

known to be difficult to germinate (Dewald et al. 1996). Seedlings grew rapidly to form a hedge

30-60 cm tall and 10-15 cm wide by the end of the growing season. Since 1995 the eastern

gamagrass hedges have continued to grow and developing into dense hedge rows.

In 1995, eastern gamagrass seeds were again planted but germination did not occur. The 1994

and 1995 seeds were purchased from the same source and the seeds were planted in the same

way. In 1995 rains (~12 mm) occurred the day after the seeds were planted. However, no rain

occurred for the following 38 days. Although eastern gamagrass has many properties desired for

a stiff grass hedge row (Dewald et al. 1996), the great difference in germination between the

germination in 1994 and 1995 highlights a problem of using eastern gamagrass. Dewald et al.

(1996) discuss the proper techniques for establishing eastern gamagrass along with other

management concerns.

Topographic surveys (Fig. 3) of the miscanthus hedge row at hedge A on the East Farm showed

10-15 cm of deposition up slope of the hedge row after four years. The deposition extends at

least 1 meter upslope of the hedge row. More surveys need to be made to determine the full

extent of the deposition pattern near this hedge row. This hedge row at the lower edge of the

field is capturing eroding particles that have moved from the field. However, this field is now in

continuous grass/clover cover so that the soil loss and concentrated flow area development each

year have been noticeably reduced. Field observation in 1995 noted the lack of a well defined

concentrated flow area as had been seen in early spring in 1991 and 1992. However, field

observation in 1999 noted the recurrence of a ephemeral gully mid way between hedges A and

G.

Surveys of the miscanthus hedge A on the BARC South Farm site made in April 1991, August

1995, and August 1999 along the same survey line (5 cm up slope of the center of the hedge

row) also showed 8-15 cm of deposition up slope of the hedge row (Fig. 3). Greater deposition

occurred in the areas where concentrated flow areas (depressions in the topographic survey)

cross the border between the strips of crops. A general smoothing of the topography up slope of

the hedge row occurred. This smoothing is probably due to the hedge row slowing and spreading

the water across a wider area as it crossed the hedge row barrier. This temporary ponding of

water would allow the sediment load carried in the runoff to be deposited over a wider area.
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287

Figure 3. Comparison of topographic surveys at hedge A on the BARC South Farm made along

the same line in April 1991, August 1995 and August 1999.

There is a general leveling along the survey line by the time of the August 1995 survey that is

especially evident in the 1998 survey. A Digital Elevation Model (DEM) created from the 1998

topographic survey up slope of the hedge A shows the topography (Fig. 4). The remnants of the

concentrated flow channel up slope of hedge A is still evident on the DEM. Field observations

noted an extensive area of deposition approximately 5-15 m up slope and 40-50 m west of the

center of the hedge A. This leveling area is also evident on the topographic survey. Whether this

deposition area is due to the hedge is not clear but it has developed since the hedge was

established. There is also evidence of the development of new concentrated flow areas below

the hedge row that is of concern.

During the four-year study no evidence was found that miscanthus produced viable seeds at any

of the hedge rows. Expansion of the miscanthus has been by shoot production that has been

rapid and vigorous in most of the hedge rows. While these miscanthus hedge rows have been

very robust, the cost of purchasing miscanthus shoots and labor needed to transplant the shoots

may reduce farmer acceptance and application of this conservation practice to concentrated flow

erosion areas. The miscanthus, once established, appears not to be affected by farm operations

including the application of herbicides used in minimum and no-till farm operations in the fields at

BARC. Minimum maintenance is required to keep the hedge effective and actively growing.

Eastern gamagrass, another candidate for use in the stiff grass hedges, was also planted

successfully at both sites. It has the advantage of being planted by seed that will make the

establishment of hedge rows easier and cheaper. Farmers can use conventional farm equipment

to plant eastern gamagrass hedges. As shown by our 1994 and 1995 eastern gamagrass

seedings, one must carefully manage the seed, the seed bed preparation, and the planting of the
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

288

eastern gamagrass seeds to insure germination (Dewald and Lougthan 1979; Dewald et al.

1996).

While this effort with grass hedges has been successful, grass hedges should not be seen as a

panacea, but as another tool in the arsenal to control soil loss and runoff. Continued efforts to

control soil loss at the point of detachment are critical. The NRCS has developed a Conservation

Practice Standard for using grass hedges for runoff and sediment control. While miscanthus is

effective as a grass hedge, indigenous grasses (i.e., eastern gamagrass, switchgrass [Panicum

virgatum L.]) should be used when possible to reduce the potential for the introduction of exotic

material into new environments.

Figure 4. Digital Elevation Map made from 1999 survey data of the area up slope of hedge A on

the BARC South Farm.

Acknowledgments

We would like to express our appreciation to Personnel from the NRCS National Plant Material

Center at Beltsville, MD who helped transplant the miscanthus. We also thank Tim Badger, Farm

Manager at the Beltsville Agricultural Research Center, who helped find good study sites and

allowed us to plant strange grasses in the fields where he tries to keep competitors from the field

crops.

References

Aase, J.K. and J.L. Pikul, Jr. 1995. Terrace formation in cropping strips protected by tall wheat

grass barriers. J. Soil and Water Conservation 50:110-112.

Brown, L.R. and E.C. Wolf. 1984. Soil erosion: the quiet crisis in the world economy. Worldwatch

Paper #60, 51 pp.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

289

Dabney, S.M., Z. Liu, M. Lane, J. Douglas, J. Zhu, and D.C. Flanagan. 1999. Landscape

benching from tillage erosion between grass hedges. Soil and Tillage Research 51:219-231.

Dabney, S.M., K.C. McGregor, L.D. Meyer, E.H. Grissinger and G.R. Foster. 1993. Vegetative

barriers for runoff and sediment control, pp. 60-70. In. J.K. Mitchell (ed.), Integrated Resource

Management and Landscape Modification for Environmental Protection, American Society of

Agricultural Engineers, St. Joseph, MI.

Dabney, S.M., L.D. Meyer, W.C. Harmon, C.V. Alonso, and G.R. Foster. 1995. Depositional

patterns of sediment trapped by grass hedges. Transaction of ASAE 38(6):1719-1729.

Dewald, C., J. Henry, S. Bruckerhoff, J.C. Ritchie, S. Dabney, D. Shepard, J. Douglas, and D.

Wolf. 1996. Guidelines for establishing warm season grass hedges for erosion control. J. Soil and

Water Conservation 51(1):16-20.

Dewald, C.L. and V.H. Lougthan. 1979. Sequential development of shoot systems components in

eastern gamagrass. J. Range Management 32(2):147-151.

Kemper, D., S. Dabney, L. Kramer, D. Dominick and T. Keep. 1992. Hedging against erosion. J.

Soil and Water Conservation 47(4):284-288.

Meyer, L.D., S.M. Dabney and W.C. Harmon. 1994. Sediment-trapping effectiveness of stiff-grass

hedges. American Society of Agricultural Engineers Paper No. 94-2186, American Society of

Agricultural Engineers, St. Joseph, MI.

Morgan, P.C. 1995. Soil Erosion and Conservation. Longman Scientific and Technical, London,

England.

National Research Council (NRC). 1993. Vetiver grass: a thin green line against erosion. National

Academy Press, Washington, DC., 169 pp.

Pimentel, D., C. Harvey, P. Resosudarmo, K. Sinclair, D. Kurz, M. McNair, S. Crist, L. Shpritz, L.

Fitton, R. Saffouri, and R. Blair. 1995. Environmental and economic costs of soil erosion and

conservation benefits. Science 267(5201):1117-1123.

Ritchie, J.C., W.D. Kemper, and J.M. Englert. 1997. Narrow stiff grass hedges for erosion control,

pp. 195-204. In: D.E. Walling and J.L. Probst (eds.), Human impact on erosion and

sedimentation, International Association of Hydrological Sciences Publication No. 245.

Siddoway, F.H. 1970. Barriers for wind erosion control and water conservation. J. Soil and Water

Conservation 25(5):180-184.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

290

Eastern Gamagrass Breeding in New York and Oklahoma

Paul R. Salon1 and Chester L. Dewald2

Introduction

There has been increased interest in breeding eastern gamagrass [Tripsacum, dactyloides (L.) L.]

in recent years due to the discovery of gynomonoecious variants with their increased seed

production potential, and the inherent superior forage quality and production potential of this

species over other warm season grasses. This paper reviews the reproductive biology and

breeding systems of eastern gamagrass and reviews the breeding efforts conducted at the

USDA-NRCS Big Flats Plant Materials Center (PMC) in Big Flats New York and the USDA-ARS

Southern Plains Range Research Station (SPRRS) in Woodward Oklahoma.

Eastern gamagrass is a tall, highly productive, long-lived, perennial, warm-season native grass.

Eastern gamagrass is palatable and highly digestible to all classes of livestock. It can be used for

hay, silage, and intensively managed pastures. It produces forage earlier in the spring than most

other warm-season grasses and later than most cool season grasses and legumes. The

perennial nature of gamagrass offers advantages over annual forages including lower fuel, labor,

and production costs.

Taxonomy

Eastern gamagrass is in the family Poaceae, tribe Andropogoneae, and subtribe Tripsacinae. It

shares the same subtribe as corn [Zea mays L.]. It is now accepted that teosinte [Zea mays L.

subsp. mexicana] is the progenitor of corn and it hybridizes freely with corn in the wild. Eastern

gamagrass hybridizes with corn under experimental conditions and frequently their chromosomes

pair during meiosis.

Tripsacum comprises 15 species in 2 sections and is native only to the Western Hemisphere

(Brink and de Wet 1983). Tripsacum dactyloides is the most widespread and morphologically

variable of the species.

Distribution

Eastern gamagrass is widely distributed from Connecticut to Nebraska south to Texas and

Florida in the United States and south to Paraguay and Brazil in South America. There are forms

of Tripsacum adapted to North American prairies and eastern coastal plains, deep sandy soils,

semi arid regions, rocky out-crops, river banks and tropical rain forests (Harlan and de Wet 1977).

Cytology

Eastern gamagrass occurs predominately at the diploid (2n=2x=36), triploid (2n=3x=54), and

tetraploid (2n=4x=72) levels although pentaploids (2n=5x=90) and hexaploids (2n=6x=108) have

been reported (Farquharson 1955).

Mode of Reproduction

The reproduction process in Tripsacum is by both sexual and facultative apomixis. Apomixis is a

form of reproduction in which seeds are produced asexually. An unreduced egg cell in the

 

1 USDA-NRCS Big Flats Plant Materials Center, Box 3266A State Route 352, Corning, NY 14830,

2 USDA-ARS Southern Plains Range Research Station, 2000 18th Street Woodward Oklahoma,

73801.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

291

embryo sac develops into a zygote without the union of the egg and sperm. Since the egg cell

has developed from mitotic rather than meiotic cell division and fertilization is absent the zygote is

genetically identical to the maternal plant from which it originated. Embryological analysis

demonstrated diploids to be exclusively sexual while the polyploid cytotypes reproduced as

facultative apomicts (Burson et al. 1990 and Sherman et. al. 1991). The predominant form of

apomictic reproduction in Tripsacum is characterized as being diplosporous pseudogamy of the

Antennaria or mitotic type. In diplosporous apomixis, the megaspore mother cells tend to

elongate prior to nuclear division. The absence of a linear tetrad and the presence of a single

elongated cell with the nucleus closer to the micropyle is characteristic of diplosporous apomixis.

The nucleus then divides mitotically to form the 8 nucleate embryo sac. In pseudogamy,

pollination is required for endosperm development. It has been found that 2-4% of the time

apomixis occurs by the Taraxacum type of diplosporous apomixis where a partial meiosis allows

for some pairing and crossing over to occur (Leblanc et. al. 1995; Kindiger and Dewald 1996).

This creates some genetic variability in the offspring without a change in chromosome number.

In the Taxaracum type of diplospory, a megaspore mother cell differentiates from the nucleus and

begins meiosis, but meiosis is inhibited at a particular stage by unknown mechanisms and the

nucleus is restored to a form that enables mitosis to occur (Kultunow 1993). This is called first

division restitution.

Monoecious and Gynomonoecious Inflorescence

Inflorescences of gamagrass typically have a female section below and a male section above on

the same raceme (monoecious). The female portion is composed of a few (1-12) solitary

spikelets that normally contain a single fertile floret each. Male spikelets are born in pairs at each

node of the rachis and contain two functional florets each with three anthers. There is a mean of

65 times more anthers than pistils (Dewald and Jackson 1988). The inflorescence exhibits

protogyny in which the female portion flowers before the male. The flowering in eastern

gamagrass is indeterminate flowering from June to September in New York.

In 1981 a gynomonoecious sex form GSF-I, (PI 483447) T. dactyloides (L.) L. forma prolificum

was discovered in an evaluation at the USDA-NRCS Manhattan Kansas Plant Materials Center

from a seed collection made in Ottawa County, Kansas. GSF-II (PI 483448) was found in 1982 at

the collection site of GSF-I. These plants exhibit gynomonoecy with pistillate spikelets below and

perfect spikelets above on the same raceme. The lowermost pistillate spikelets and the thick

rachis form a cupulate fruitcase structure similar to that of the monoecious form (MSF). The

basal solitary spikelets have two fertile pistillate florets instead of one. Each of the paired

spikelets, which are normally male, contains two functional female florets and rudimentary

stamens. At the extreme apex of the inflorescence a few paired spikelets contain two functional

perfect (male and female) florets. The cupules in the basal portion of the GSF racemes are

generally well developed but become progressively more shallow and eventually disappear in the

apical portion of the raceme (Dewald and Dayton 1985). The GSF variant averaged 22 times

more pistils than the MSF inflorescence indicating a seed increase potential of 20 fold. The

anthers on the GSF inflorescence is only 22% of those of the MSF type resulting in unsatisfactory

seed set (Dewald and Jackson 1988). The size and weight of the caryopses originating in the

region of paired spikelets on the GSF raceme are about 25% less than the size and weight of

those originating on the lower solitary spikelets of the MSF plants. Seed produced by GSF plants

have good germination (Jackson 1992).

The GSF trait is governed by a recessive gene. The progeny of selfed and intermated F1 hybrids

segregated 3 MSF to 1 GSF indicating the gynomonoecious condition is under recessive

monogenic control. There was sufficient deviation to suspect the presence of structural modifiers

in certain cross combinations. (Dewald et. al. 1987).
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292

Breeding

Purpose

The characteristics of gamagrass which have limited its development and cultivation have been

low seed production, inferior seed quality, and establishment difficulties. Breeding efforts have

increased since the discovery of the gynomonoecious form with the hope to solve some of these

problems. Eastern gamagrass has a wide geographic range and is adapted to many soils and

climate conditions. There is a vast amount of genetic diversity within eastern gamagrass and

between Tripsacum species which can be tapped for increased yield, seed production, and

disease and insect resistance. The inherent forage quality is very good and should be

maintained or improved during the breeding process. Its area of adaptation may be moved

northward with improvements in winter hardiness and frost heaving resistance. Variability has

been observed in the leaf width, stem heights and width, disease resistance, forage quality,

maturity date, yield, plant architecture, degree of center persistence, and seed head shatter

resistance.

History of Present Varieties

‘Pete’ eastern gamagrass (PI 421612), formerly designated PMK-24, originated from seed

collections made in 1958 from native stands in Kansas and Oklahoma. In 1960, seventy original

seed lots were bulked to establish the first generation of a composite strain. The strain was

advanced through three generations via combine harvesting and replanting of open-pollinated

seed. The first generation varied considerably in maturity; some selection for uniformity of

maturity is presumed to have occurred during this process. The third generation of the composite

was both the breeders seed field and the foundation field. The strain was released on a

germplasm basis in 1974. A formal release of foundation ‘Pete’ was made to certified growers in

1989 by the USDA-SCS, USDA-ARS and Kansas and Oklahoma Agricultural Experiment

Stations (Fine et. al. 1990).

‘Iuka’ is based on a collection of over 500 accessions from Oklahoma, Texas, Kansas, and

Arkansas. In 1979 a 21-plant selection based on apparent forage value was made from the

original collection. A one-acre block was vegetatively established then advanced two generations.

Breeding at the Diploid Level Using GSF Germplasm

Considerable work has been done breeding eastern gamagrass at the USDA-ARS Southern

Plains Range Research Station (SPRRS) at Woodward Oklahoma. Many initial hybrids were

made from crosses using a wide array of MSF accessions onto the GSF-I and GSF-II variants as

well as backcrossing and intercrossing with GSF hybrids to come up with unique and vigorous

germplasm.

In 1983-84 over 450 northern accessions from collections located at the USDA-ARS SPRRS and

the USDA-NRCS Manhattan Kansas Plant Materials Center were divided and brought to the Big

Flats Plant Materials Center. After several years of over-wintering in this climate superior

accessions were selected and used as pollinators onto GSF-I. After intercrossing the F1

generation, 320 GSF genotypes were produced. 25 genotypes were selected for further

evaluation based on good agronomic and seed production characteristics.

At the USDA-ARS SPRRS shatter resistance, a primary goal, has not been achieved in the

breeding program. Some progress has been made in identifying and selecting for reduced rachis

internodes for shatter resistance. Accessions have been identified in which seeds mature prior to

disarticulation of rachis internodes which would allow harvest before shattering. More

determinate flowering, which occurs in material with branched lateral inflorescences, would make

timing of harvest easier to pinpoint.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

293

The lack of an adequate amount of pollen in the GSF inflorescence has always been

acknowledged as a problem for seed production. A solution to this problem was to use

heterozygous MSF plants in pollinator rows similar to corn seed production (Salon et. al. 1990).

An alternative is the use of intermediate sex forms that are a product of the vast number of

hybrids being produced in Oklahoma. They are characterized by having solitary, sometimes

paired, female spikelets on the basal portion of the racemes with paired female fertile florets

extending upwards for one-fourth to one-half the length of the tassel section. Spikelets of the

intermediate type have two fertile florets instead of one, and seed production potential is

increased by 10-15 fold compared to the MSF type. There is a sufficient increase in pollen

production over the GSF type to insure adequate pollination. In certain genetic backgrounds,

partial sex reversal (feminization of 1⁄4 to 3⁄4 of the male-paired spikelets in the tassel) occurs in

diploids, which are heterozygous for the gsf1 gene, i.e. gsf1/GSF1 genotypes. When

intermediate sex form plants are selfed the normal ratio of progeny is 1 gynomonoecious: 2

intermediate: 1 MSF sex form.

Selection at the Tetraploid Level

A 450-accession evaluation nursery was established at Big Flats, other collections were made

including five from near Beltsville Maryland. These plants exhibited growth characteristics and

maturity dates much different than the bulk of the collection, with wider lighter green leaves

upright growth habit and later flowering. Divisions of these plants were made and a seed

increase block was formed (PI 591483). Flow cytometry data showed that these were tetraploid.

They flowered about 2 weeks later than ’Pete’ and yielded about 25% more biomass. There have

been no molecular studies done to differentiate between the initial clones and their progeny to

determine if they are genetically different. Progeny from this composite are very uniform.

Observations at Big Flats indicate problems with winter hardiness during establishment in some

years; therefore this composite will be targeted for use in southern Pennsylvania and the MidAtlantic region.

Breeding for Forage Quality

A study was conducted at the USDA-NRCS Big Flats Plant Materials Center and Cornell

University looking at the forage quality of eastern gamagrass as measured by crude protein (CP),

neutral detergent fiber (NDF), acid digestible fiber (ADF), lignin, in vitro true digestibility (IVTD)

and digestible NDF. The reproductive and vegetative tillers of six gamagrass accessions plus the

cultivar (cv) ‘Pete’ were evaluated for three first cutting dates in 1997 and 1998. There were

significant differences between genotypes for vegetative tillers for all variables measured, except

for ADF in 1997 and for lignin in 1998. For reproductive tillers, there were significant differences

except for NDF and lignin in 1998. It seems that variability exists between eastern gamagrass

accessions that could be used in a breeding program. Only minor forage quality differences,

which varied by year and tiller type, were found between reproductive and vegetative tillers when

averaged across accessions and cutting dates.

Breeding for Frost Heaving Resistance

Frost heaving is a major problem in some years reducing the successful establishment of eastern

gamagrass in the Northeast since many of the poorly drained soils that gamagrass could grow on

due to its aerenchyma cells in the roots are prone to frost heaving. A field of ‘Pete’ gamagrass,

which exhibited good spring establishment in 1996, had severe frost heaving over the winter with

over 75% of the plants killed. Four hundred of the surviving plants were dug up in 1998 when

dormant and immediately replanted into a crossing block at the Big Flats PMC. Seed was

harvested in 1999 and will be replanted into a frost heaving prone soil in the year 2000 for a

second cycle of selection.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

294

Incorporation of the GSF Trait in Polyploids to Stabilize with Apomixis and the Production

of Sexual Tetraploids

The GSF trait increases the seed production potential of eastern gamagrass several fold and is

being utilized in several breeding programs. It occurs in nature at the diploid level. The GSF trait

is governed by a recessive gene. Tetraploids are apomictic and many are found to be more

robust and productive than the diploids with later maturity dates but have the MSF seed head.

The GSF inflorescence does not produce enough pollen for adequate seed set or for the

production of true breeding lines in seed production fields. The transfer of the GSF trait from the

diploid level to the tetraploid level, therefore, has several advantages. It will allow, by crossing

apomictic plants as pollen parents and intermating progeny, the ability to fix the GSF trait with

apomixis. Eastern gamagrass shows a high degree of shattering. Breeding apomixis into the

genotypes used in seed production fields would practically eliminate the production of “off” types

from the shattered seed and would reduce genetic drift. This would increase the length of time

seed production fields can be maintained. The stabilization of other traits as well as the potential

to maintain hybrid vigor may be possible with the use of apomixis in eastern gamagrass breeding

programs.

On the other hand, sexually reproducing tetraploid eastern gamagrass will permit recombination

and conventional breeding at the tetraploid level. The tetraploid gamagrass plants found along

the Northeast and Mid-Atlantic coastal areas are larger, more robust, and flower around 2 weeks

later than the diploids obtained from the Midwest. The tetraploids are less winter-hardy and

appear to decline with center dieback more quickly than the diploids. It would be beneficial to be

able to improve winter hardiness and longevity in these tetraploids by conventional breeding

methods. Sexual tetraploids will also be useful for future genetic studies of the inheritance of

apomixis and for study of the inheritance of the GSF trait at the tetraploid level (Salon and Earle

1998).

Chromosome Doubling of GSF Eastern Gamagrass in Tissue Culture

Tissue culture techniques were used to double the chromosome number of eastern gamagrass at

the Big Flats Plant Materials Center and Cornell University. Shoots of diploid (2n=2x=36) GSF-I

(PI-483447) plants were derived from callus initiated from immature inflorescences and embryos.

These shoots were induced to microtiller in the presence of 3 mg l-1 benzyladenine.

Amiprophosmethyl and colchicine were used to induce chromosome doubling to rapidly dividing

microtillers. These plants were tetraploid (2n=4x=72) as determined by flow cytometry and root

tip chromosome counts. These plants were morphologically normal and produced seed with the

GSF inflorescence. Test crosses were made with a known diploid. Flow cytometry and

chromosome counts showed that the progeny were triploid, proving that the induced tetraploids

reproduced sexually (Salon and Earle 1998). The induced sexual GSF tetraploid (PI-591482)

was released as germplasm by the USDA-NRCS and Cornell University and registered as SG4X1 (Salon and Pardee 1996).

Genome Accumulation

A method to transfer genes from the diploid level to the tetraploid level and from polyploids down

to the diploid level is being used by the USDA-ARS SPRRS in Woodward Oklahoma. It is

referred to as genome accumulation. In this method fertile apomictic triploids are formed by 2x X

4x crosses. Triploid hybrids of eastern gamagrass are largely sterile, but a few 1-10% are

partially female fertile due to apomictic reproduction. Four of these released by the USDA-ARS

SPRRS, were selected out of 832 triploids from four hybrid combinations evaluated for seed set,

pollen fertility, and agronomic attributes (Dewald et al. 1992). Fertile triploids can be used to

provide an intermediate step for the creation of new and genetically unique tetraploid germplasm.

These triploids are crossed using diploids as the pollen parent and due to the formation of

unreduced gametes by the triploids, tetraploid progeny are formed. Fertile triploid eastern

gamagrass hybrids often produce tetraploid progeny at a frequency of 10-30% (Dewald and
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

295

Kindiger 1994 a&b). These tetraploids carry three genomes (54 chromosomes) from the triploid

maternal parent and one genome (18 chromosomes) from the reduced gamete of the diploid

parent. They are called BIII hybrids resulting from a 2n + n mating (Bashaw and Hignight 1990;

Bashaw et al. 1992). These tetraploids are apomictic but now carry genes from their diploid

parent. The introgression of diploid germplasm into apomictic tetraploid germplasm provides for

the enrichment of the genetic diversity at the tetraploid level.

Hexaploids can also be formed by genome accumulation. Using tetraploid apomictic germplasm

as the maternal parent crossed with other apomictic tetraploids, BIII hybrids are formed 5-8% of

the time. An experimental hybrid, WW-2190 selected for high fertility, was reported to produce

BIII hybrid offspring 50% of the time. These hybrids receive 72 chromosomes from the maternal

parent from unreduced embryos and 36 chromosomes from the reduced pollen parent resulting in

a (2n=6x=108) hexaploid. These hexaploids have proven useful as a bridge for moving apomictic

tetraploid germplasm to the sexual diploid level. When crosses are made between diploids as the

maternal parent and hexaploids as pollen parents, 99% of the resulting progeny are diploids. It is

suspected that hexaploids produce pollen of many ploidy levels and that the pollen carrying the

haploid number is far more competitive resulting in diploid progeny. Diploids generated from this

2x X 6x cross are highly variable and possess a wide diversity of alleles contributed from the

apomictic polyploid genotypes (Kindiger and Dewald 1997).

This method has been successfully used to move the GSF trait from the diploid level to the

triploid level where it was stabilized by apomixis. FGT-1 a fertile gynomonoecious apomictic

triploid, was released by the USDA-ARS SPRRS in Woodward, Oklahoma (Dewald and Kindiger

1996). FGT-1 was developed by combining recessive genes for gynomonoecy from diploids

(2n=2x=36) with genes for apomixis from polyploids in three generations of interploidy matings. A

first generation fertile triploid hybrid was produced from a GSF plant as the maternal parent. This

triploid was crossed with a mixture of pollen from 7 heterozygous diploids for the gsf trait creating

a BIII tetraploid. This tetraploid was crossed onto a GSF diploid; out of 90 triploid progeny

recovered three were gynomonoecious and one was relatively fertile (35-55% seed set) exhibiting

both gynomonoecy and apomictic reproduction.

Interspecific Hybridization in Tripsacum

Crosses between Tripsacum dactyloides and all other Tripsacum species (Cutler and Anderson

1941) are readily accomplished, regardless of ploidy or the taxonomic section a species had been

assigned (Brink and de Wet 1983). No interspecific crossing barriers have been observed by

work conducted at the USDA-ARS in Woodward Oklahoma on T. dactyloides, T. andersonii J.R.

Gray, T. floridanum Porter ex Vasey, T. maizar Hern.-Xol. & Randolph, and T. zopilotense Hern.-

Xol. & Randolph. Various interspecific hybrids have identical reproductive characteristics with the

production of BIII hybrids. Most Tripsacum species can be crossed to yield viable hybrids. T.

floridanum crosses with T. dactyloides to yield viable sexually fertile hybrids and the two species

should probably be considered one. Sexual diploids crossed with apomictic tetraploids of a

different species will yield allotriploids, some of which will be seed fertile due to apomixis. These

can then be crossed by diploids to yield allotetraploids by genome accumulation. Interspecific

crosses provide an opportunity to expand the genetic diversity across the species (Kindiger and

Dewald 1997).

Hybridization of Tripsacum and Maize

Corn was crossed with gamagrass as early as 1931 (Manglesdorf and Reeves 1931). Many

workers have since made similar crosses using corn as the female parent and these hybrids are

female fertile. Further backcrossing to corn results in recovery of pure corn with slight to no

introgression of gamagrass germplasm after 4 to 8 backcrosses with corn. Recent work has been

conducted at the USDA-ARS SPRRS crossing Tripsacum onto corn for the purpose of

transferring genes for apomixis from eastern gamagrass into corn.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

296

Until recently, attempts to use gamagrass as a female parent in crosses with corn have resulted

in only a few sterile hybrids. In 1995, the first fertile hybrid produced by crossing gamagrass as

the female parent with corn was achieved at the USDA-ARS SPRRS. This hybrid had 18

chromosomes of gamagrass and 10 from corn. When the hybrid was backcrossed to corn, plants

with thirty-eight chromosomes (18 gamagrass + 20 corn) resulted. In further backcrossing to corn,

all gamagrass chromosomes were eliminated leaving only corn chromosomes in a gamagrass

cytoplasm. It is expected that the cytoplasmic gene pool of gamagrass will interact with the

nuclear genes of corn to result in an improved product. Test on disease, insect, and stress

tolerance, nutritive value, yield and adaptation are in progress (Dewald et al. 1999).

References

Bashaw, E.C. and K.W. Hignight. 1990. Gene transfer in apomictic buffelgrass through

fertilization of an unreduced egg. Crop Sci. 30: 571-575.

Bashaw, E.C. Hussey, M.A. and K.W. Hignight. 1992. Hybridization (N+N and 2N+N) of

facultative apomictic species in the Pennisetum agamic complex. Int. J. Plant Sci. 153: 466-470.

Brink, D.E. and J.M.J. de Wet. 1983. Supraspecific groups in Tripsacum (Graminae). Systematic

Botany 8:243-249.

Burson, B.L., P.W. Voigt, R.A. Sherman, and C.L. Dewald. 1990. Apomixis and sexuality in

eastern gamagrass. Crop Sci. 30:86-89.

Cutler, H.C. and E.G. Anderson. 1941. A preliminary survey of the genus Tripsacum. Ann. Mo.

Bot. Gard. 28:249-269.

Dewald, C.L., and R.S. Dayton. 1985. Registration of gynomonoecious germplasm (GSFI and

GSF-II) of eastern gamagrass. Crop Sci. 25:715.

Dewald, C.L., B.L. Burson, J.M.J. deWet, and J.R. Harlan. 1987. Morphology, inheritance, and

evolutionary significance of sex reversal in Tripsacum dactyloides (Poaceae). Amer. J. Bot.

74:1055-1059.

Dewald, C.L. and L. Jackson. 1988. Breeding system influence on spikelet number, glume

dimensions, and sex ratios of eastern gamagrass, In: A .Davis and G. Standford (ed.). Proc. 10th

North American Prairie Conf. p.118-120. Native Prairies Association of Texas, Dallas TX.

Dewald, C.L., C.M. Taliaferro and P.C. Dunfield. 1992. Registration of four fertile triploid

germplasm lines of eastern gamagrass. Crop Sci. 32:504.

Dewald, C.L., and B. Kindiger. 1994a. Genetic transfer of gynomonoecy from diploid to triploid

eastern gamagrass. Crop Sci. 34:1259-1262.

Dewald, C.L., and B. Kindiger. 1994b. Genome accumulation in eastern gamagrass, Tripsacum

dactyloides (L.) L. (Poaceae). Genetica 92:197-201.

Dewald, C.L., and B. Kindiger. 1996. Registration of fertile gynomonoecious triploid (FGT-1)

eastern gamagrass germplasm. Crop Sci. 36:219.

Dewald, C.L., P.L. Sims, Y. Li and V. Sokolov. 1999. Novel cytoplasm for maize. 41st Annual

Maize Genetics Conference Programs and Abstracts, March 1999, Lake Geneva, WI. P.100.

Farquharson, L.I. 1955. Apomixis and polyembryony in Tripsacum dactyloides. Am. J. Bot.

42:737-743.
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Fine, G.L., F.L. Barnett, K.L. Anderson, R.D. Lippert, and E.T. Jacobson. 1990. Registration of

‘Pete’ eastern gamagrass. Crop Sci. 30:371-372.

Harlan, J.R., and J.M.J. deWet. 1977. Pathways of genetic transfer from Tripsacum to Zea mays

Maize. Proc. Natl. Acad. Sci. 74:3494-3497.

Jackson, L.L., C.L. Dewald, and C.C. Bohlen. 1992. A macromutation in Tripsacum dactyloides

(Poaceae): Consequences for seed size, germination and seedling establishment. Am. J. Bot.

79:1031-1038.

Kindiger, B. and C.L. Dewald. 1996. A system for genetic change in apomictic eastern

gamagrass. Crop Sci. 36:250-255.

Kindiger, B. and C.L. Dewald. 1997. The reproductive versatility of eastern gamagrass. Crop Sci.

37:1351-1360.

Koltunow, A.M. 1993. Apomixis: embryo sacs and embryos formed without meiosis or fertilization

of ovules. The Plant Cell 5:1425-1437.

Leblanc, O., Peel, M.D. Carman, J.G. and Savidan, Y. 1995. Megasporogenesis and

megagametogenesis in several Tripsacum species (Poaceae). Am. J. Bot. 82: 57-63.

Mangelsdorf, P.C. and R.G. Reeves. 1931. Hybridization of maize, Tripsacum, and Euchlaena. J.

Hered. 22(11):328-343.

Salon, P.R., J.R. Dickerson, and M. van der Grinten. 1990. A seed production method for eastern

gamagrass. P.190-193. In: Proc. Am. Forage and Grassl. Council, Blacksburg. Va. 6-9 June,

1990. American Forage and Grassl. Council, Belleville, Pa.

Salon, P.R., and W.D. Pardee. 1996. Registration of SG4X-1 germplasm of eastern gamagrass.

Crop Sci. 36:1425.

Salon, P.R. and E.D. Earle. 1998. Chromosome doubling and mode of reproduction of induced

tetraploids of eastern gamagrass (Tripsacum dactyloides L.). Plant Cell Reports 17:881-885.

Sherman, R.A., P.W. Voigt, B.L. Burson, and C.L. Dewald. 1991. Apomixis in diploid x triploid

Tripsacum dactyloides hybrids. Genome 34:528-532.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

298

Eastern Gamagrass Forage Quality as Influenced by Harvest Management

Paul R. Salon1 and Debbie J.R. Cherney2

Introduction

Eastern gamagrass [Tripsacum dactyloides (L). L.] is a highly productive native perennial, warm

season grass, which is palatable and highly digestible. Eastern gamagrass can be utilized for

hay, silage, and intensively managed pasture. Most forage quality and yield information for

eastern gamagrass has been generated in the Midwest and South (Brejda et al. 1994 and 1996;

Burns et al. 1992; Faix et al. 1980; Horner et. al. 1985; and Wright et al. 1983). It is suspected

that although yields maybe lower in the Northeast, the forage quality of warm season grasses

may be superior to those grown in warmer regions (Van Soest 1994). Information on forage

quality and yield is needed in the Northeast to help to determine the feasibility of using

gamagrass in the region. It is of interest to determine the proper growth stage to cut eastern

gamagrass and to ascertain its rate of decline during maturity. Information is needed about

forage quality variability within eastern gamagrass. Reproductive and vegetative tillers were

looked at separately in order to determine if selecting for specific tiller types in a breeding

program would influence total herbage forage quality and to compare eastern gamagrass with

other warm season grasses studied in a similar fashion (Griffin and Jung 1983; Perry and

Baltensperger 1979 and Twidwell et al. 1988). Objectives were to 1) evaluate the forage quality

of eastern gamagrass grown in the Northeast, 2) determine the effects of cutting dates and

intervals on forage quality, 3) assess forage quality differences between accessions for

reproductive and vegetative tillers, and 4) evaluate the difference in forage quality between

reproductive and vegetative tillers of eastern gamagrass.

Materials and Methods

Two forage quality studies were conducted in 1997 and 1998. A time of cutting study was

conducted on an established 6-year-old stand of eastern gamagrass, cultivar ‘Pete’, on a Unadilla

silt loam soil at Big Flats, New York. The stand received 112 kg ha-1 yr-1 of nitrogen on June 4,

1997 and May 27, 1998. Three replicated plots were harvested (4 individual plants per rep) at

three 1st cutting dates, starting on 6/13/97 and 5/28/98 and taken at weekly intervals. A second

cutting was sampled at three intervals, four, five and six weeks.

A forage quality study was conducted evaluating the vegetative and reproductive tillers of six

agronomically superior accessions and ‘Pete’. Four individual plants were sampled at the three 1st

cutting dates for each accession. Plants were dried at 60oC. Material was ground to pass through

a 2-mm screen in a Wiley mill, and were then reground to pass a through a 1-mm screen in a

cyclone mill (Udy Corp., Fort Collins, Co) in preparation for quality analyses. Samples (0.5 g)

were sequentially analyzed for neutral detergent fiber (NDF), acid detergent fiber (ADF), and

sulfuric acid lignin according to procedures described by Van Soest et al. (1991), except that the

filter bag technique was used with the ANKOM 200/220 Fiber Analyzer. In vitro true digestibility

(IVTD, 0.25 g), and digestible NDF (dNDF) were determined according to Cherney et al. (1997)

using the rumen fluid buffer described by (Marten and Barnes 1980) and using the Dairy II 200/220

In Vitro Incubator and the ANKOM 200/220 Fiber Analyzer. The buffer contained urea (0.5g l-1) as

supplemental N. Ruminal fluid inoculum was obtained from a non-lactating, rumen-fistulated,

Holstein cow fed a medium quality orchardgrass hay diet for ad libitum intake. Nitrogen was

determined by a Dumas type N combustion analyzer (Leco, St. Joseph, MI).

Results and Discussion

Time Of Cutting Study

 

1 USDA-NRCS Big Flats Plant Materials Center, Box 3266A, State Route 352, Corning, NY

14830, 2

Cornell University, Dept. of Animal Sci., 324 Morrison Hall, Ithaca, NY 14853.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

299

The NDF, ADF, and lignin all increased with advancing initial spring harvest date, while IVTD and

dNDF declined in first cutting samples, as expected (Table 1). The CP content of eastern

gamagrass was not as influenced by harvest date as were other variables, such that no

differences were detected in 1998 (P>0.05). This may have been due to a cold wet June in 1998,

with average temperatures 2.4o

C cooler and 3.8 cm more rain than the 25-yr average. The rate

of maturity for the eastern gamagrass was slower in 1998 than in 1997. Although the dates of the

initial first cutting varied by two weeks (June 13, 1997 and May 29, 1998), growing degree days

(GDD) at that point were similar (363 and 339, respectively, for 1997 and 1998). There were

significant differences for most variables measured between first cutting dates so that timing

appears to be as important in gamagrass as it is in most perennial forages (Cherney et al. 1993).

The date of the initial first cutting will be dependent on an acceptable yield and how it impacts

subsequent cuttings (Table 2). The second cutting yield increased significantly as the length of

the cutting interval increased 1.9, 2.3, and 2.9 Mg ha-1 for the 4, 5, and 6 week cutting interval

respectively. The NDF of eastern gamagrass was relatively high in comparison to perennial cool

season grasses grown in NY (Cherney et al. 1993), but digestibility of both dry matter and NDF

was high. The higher than expected NDF may have been due to a low cutting height of 4 inches.

The CP in both years was higher than the average for perennial grasses analyzed at the

Northeast Dairy Herd Improvement Laboratory, Ithaca, NY from May 97-April 98. Crude protein in

both years was higher than that reported by Brejda et al. (1996) even at their rate of fertilizer N

application of 224 kg ha-1. This data suggests that acceptable forage quality can be achieved with

proper management.

Table 1. Influence of harvest date on forage quality parameters (g kg-1) of eastern gamagrass,

first cutting.

________________________________________________________________

Harvest Date NDF1 ADF Lignin IVTD dNDF CP

 

1997

June 13 693a 312a 33a 798a 727a 163a

June 20 773b 381b 62b 751b 668ab 164a

June 27 770b 396b 68b 752b 673b 159b

1998

May 29 709a 319a 23a 843a 778a 135a

June 4 721 b 338b 26a 815ab 744ab 131a

June 12 746b 355c 30b 794b 724b 130a

__________________________________________________________________

1

NDF = neutral detergent fiber, ADF = acid detergent fiber, IVTD = in vitro true digestibility,

dNDF = digestible NDF, CP = crude protein.

a,b,c Least squares means in the same column and year with different superscripts differ (P<0.05).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

300

Table 2. Total eastern gamagrass yield1 (Mg ha-1) 1998.

 

Hdi2 1st cut 2nd cut 3rd cut Total

 

5/29 2.20a 2.06b 2.25a 6.51a

6/4 2.38ab 2.70a 1.75a 6.83a

6/12 3.26b 2.29b 1.58a 7.13a

 1 To convert Mg ha-1 to tons ac-1 multiply by 0.446 2

 Initial harvest date

a,b Least squares means in the same column with different superscripts differ (P<0.05).

Second-cutting samples were affected by initial harvest date and cutting interval, as well as the

interaction between the two (Table 3). There were significant interactions between initial harvest

date and cutting interval for NDF, ADF, and lignin. Results varied by year and treatment regime,

although the range in NDF between cutting regimes was not large in either year (Table 4). The

mean crude protein was clearly reduced for the six week second cutting interval regardless of the

first cutting date (Table 4). The CP for second cuttings was lower than for first cuttings. There was

no topdressing following first cutting. The interaction between initial harvest date and cutting

interval was not significant in 1997 or 1998 for IVTD and dNDF, allowing for discussion of main

effects. Initial first cutting date had no effect on regrowth IVTD and dNDF in 1997 (Table 5). In

1998, delaying initial harvest resulted in lower second cutting IVTD and dNDF. Differences

between years are likely due to environmental differences. Increasing cutting interval decreased

IVTD and dNDF in both 1997 and 1998 (Table 5). Results of this cutting study clearly indicate that

the third cutting interval (6 weeks) is too long to insure acceptable quality. A 5-week cutting

interval or less depending on forage yield is recommended. Delaying harvest until later in spring

may also adversely impact forage quality of the second cutting, though this is dependent on

climate.

Variety study

There were significant differences between the genotypes for vegetative tillers for all variables

measured except for ADF in 1997 and for NDF and Lignin in 1998 (Table 6). For reproductive

tillers only lignin in 1998 was not significantly different. Later harvest date resulted in higher

(P<0.05) NDF, ADF, and lignin, as might be expected. In vitro digestibility, dNDF, and crude

protein generally declined with advancing harvest date in 1997 and 1998. There appears to be

little difference in forage quality between reproductive and vegetative tillers when cut at the

appropriate time. There are only minor differences between their means with high forage quality

indicator values switching between tiller types between years for some of the variables measured.

Conclusions

Eastern gamagrass provides good quality forage, provided that adequate harvest management is

maintained. Crude protein levels of 1st cuttings in 1997 averaged 16%. Although NDF was high,

the fiber digestibility and the total digestibility were very high. Based on data in this study, a 5-

week cutting interval is recommended unless there is sufficient yield to warrant an earlier cut.

There were significant differences between accessions for most forage quality variables

measured for both tiller types. IVTD and dNDF had the most variability between accessions for

both tiller types and CP for reproductive tillers. This was noted by the spread in the mean
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

301

separations between accessions for these parameters. Only minor differences in forage quality

were found between reproductive and vegetative tillers when averaged across accessions.

Table 3. Mean square errors as influenced by initial harvest date, cutting interval,

and initial harvest date x cutting interval.

_____________________________________________________________________

Source NDF ADF Lignin IVTD 

dNDF CP

 _____________________________________________________________________

1997

Initial harvest date 45.13 61.63 1.62 132.76

165.76 15.70 

(0.01)1 (0.01) (0.01) (0.01)

(0.01) (0.01)

Cutting Interval 0.38 1.18 0.23 194.02

362.51 28.96

(0.83) (0.49) (0.11) (0.01)

(0.01) (0.01)

Hdi2 x Cutting Interval 27.85 13.74 0.77 19.57

27.21 7.87

(0.01) (0.01) (0.01) (0.27)

(0.39) (0.01)

1998

Initial harvest date 10.42 107.80 6.43 79.74

105.90 83.98

(0.02) (0.01) (0.04) (0.01)

(0.01) (0.01)

Cutting Interval 11.39 179.09 4.16 333.63

584.90 173.03

(0.01) (0.01) (0.04) (0.01)

(0.01) (0.01)

Hdi2 x Cutting Interval 14.39 32.49 7.54 6.64

19.34 2.91

(0.01) (0.01) (0.01) (0.26)

(0.08) (0.04)

______________________________________________________________________

1

 Probability level

2 Initial harvest date
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

302

Table 4. Influence of harvest date on forage quality parameters (g kg-1) of eastern gamagrass,

second cutting.

_________________________________________________________________________

Hdi1 CI2 NDF ADF Lignin IVTD dNDF CP

 

1997

6/13 4 wk 705 354 43 777 684 128

1 5 wk 708 366 46 717 601 109

1 6 wk 733 379 51 698 589 106

6/20 4 wk 711 364 49 728 617 121

2 5 wk 726 367 48 705 594 127

2 6 wk 719 371 49 698 582 100

6/27 4 wk 711 355 47 770 677 134

3 5 wk 699 341 44 744 634 124

3 6 wk 681 335 43 739 618 123

1998

5/29 4 wk 743 354 41 815 751 159

1 5 wk 723 357 32 793 713 126

1 6 wk 722 364 29 747 647 108

6/4 4 wk 715 345 31 818 745 129

2 5 wk 713 359 29 782 694 113

2 6 wk 735 409 40 742 649 82

6/12 4 wk 726 361 32 778 694 119

3 5 wk 728 395 39 761 679 101

3 6 wk 738 422 52 729 634 80

 1

Hdi = initial harvest date, 2CI = cutting interval,

Table 5. Influence of initial first cutting and cutting interval on forage quality parameters (g kg-1) of

eastern gamagrass second cutting

 

IVTD1 dNDF

 

Harvest Date

1997

June 13 729a 622a

June 20 711a 598a

June 27 751a 643a

1998

May 29 786a 707a

June 4 782a 697a

June 12 756b 668b

Cutting Interval

1997

4-wk 757a 658a

5-wk 721b 609b

6-wk 711b 596b

1998

4-wk 804a 729a

5-wk 778b 696b

6-wk 739c 643c

_______________________________________________________________________________________________________________________

1

IVTD = in vitro true digestibility; dNDF = digestible neutral detergent fiber.

a,b,c Least squares means in the same column, year and main effect with different superscripts

differ (P<0.05).
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Table 6. Neutral Detergent fiber (NDF; g kg-1), crude protein (CP; g kg-1) and in vitro true digestibility (IVTD; g kg-1) of vege

tillers of eastern gamagrass as influenced by accession.

__________________________________________________________________________________________________

NDF CP IVTD

Accession Vegetative Reproductive Vegetative Reproductive Vegetative Re1997215 714ab 676b 131b 121b 84.1ab 316 688bc 692a 129b 109cd 81.2d 519 713ab 676bc 123b 102d 83.4bc 521 699abc 662cd 129b 105cd 81.3d 538 673c 660d 133ab 121b 82.1cd 716 720a 663bcd 127b 113cb 85.3a ‘PETE’ 695abc 653d 147a 132a 82.2cd 1998215 673ab 685bcd 156a 168ab 82.8b 316 673ab 700ab 142bc 152cd 79.9d 519 670ab 690bcd 136bc 146d 82.5b 521 664abc 691bc 137bc 161bc 80.6cd 538 674d 664abc 135bc 152d 81.7cb 716 658bc 682cd 146ab 171a 86.2a ‘PETE’ 670ab 709a 132c 132e 81.5bcd 

__________________________________________________________________________________________________

a, b, c, dLeast squares means in the same column and year with different superscripts differ (P<0.05).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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References

Brejda, J.J., J.R. Brown, J.M. Asplund, T.E. Lorenz, J.L. Reid, and J. Henry. 1994. Eastern

gamagrass silage fermentation characteristics and quality under different nitrogen rates. J. Prod.

Agric. 7:477-482.

Brejda, J.J., J.R. Brown, T.E. Lorenz, J. Henry, J.L. Reid, and S.R. Lowry. 1996. Eastern

gamagrass responses to different harvest intervals and nitrogen rates in northern Missouri. J.

Prod. Agric. 9:130-135.

Burns, J.C., D.S. Fisher, K.R. Pond, and D.H. Timothy. 1992. Diet Characteristics, digesta

kinetics, and dry matter intake of steers grazing eastern gamagrass. J. Anim. Sci. 70:1251-1261.

Cherney, D.J.R., J.H. Cherney, and R.F. Lucey. 1993. In vitro digestion kinetics and quality of

perennial grasses as influenced by maturity. J. Dairy Sci. 76:790-797.

Cherney, D.J.R., M.J. Traxler, and J.B. Robertson. 1997. Use of Ankom fiber determination

systems to determine digestibility. NIRS Forage and Feed Testing Consortium Annual

Conference, Feb. 19-20, 1997, Madison, WI.

Faix, J.J., C.J. Kaiser, and F.C. Hinds. 1980. Quality, yield, and survival of asiatic bluestem and

an eastern gamagrass in southern Illinois. J. Range Manage. 33:388-390.

Griffin, J.L., and G.A. Jung. 1983. Leaf and stem forage quality of big bluestem and switchgrass.

Agron. J. 75:723-726.

Horner, J.L., L.J. Bush, G.D. Adams, and C.M. Taliaferro. 1985. Comparative nutritional value of

eastern gamagrass and alfalfa hay for dairy cows. J. Dairy Sci. 68:2615-2620.

Marten, G. C., and R. F. Barnes. 1980. Prediction of energy digestibility of forages with in vitro

rumen fermentation and fungal enzyme systems. p. 61 In: W.J. Pigden, C.C. Balch, and M.

Graham (eds.). Standardization of analytical methodology for feeds. Int. Devel. Res. Ctr., Ottawa,

ON, Can.

Perry, L.J., and D.D. Baltensperger. 1979. Leaf and stem yields and forage quality of three Nfertilized warm-season grasses. Agron. J. 71:355-358.

Twidwell, E.K., K.D. Johnson, J.H. Cherney, and J.J. Volenec. 1988. Forage quality and digestion

kinetics of switchgrass herbage and morphological components, Crop Sci. 28:778-782.

Van Soest, P.J. 1994. Nutritional ecology of the ruminant. Second Ed., Cornell University Press,

Ithaca, N.Y. 475p.

Van Soest, P.J., J.B. Robertson, J.B., and B.A. Lewis. 1991. Methods for dietary fiber, neutral

detergent fiber, and nonstarch polysaccharides in relation to animal nutrition. J. of Dairy Sci. 74:

3583-3597.

Wright, L.S., C.M. Taliaferro, and F.P. Horn. 1983. Variability of morphological and agronomic

traits in eastern gamagrass accessions. Crop Sci. 23(1): 135-138.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

305

Eastern Gamagrass Response to Accent (nicosulfuron), Basis

(rimsulfuron), and Plateau (imazapic) Herbicides in Comparison to a Few

Common Corn Herbicides

Paul R. Salon1 and Martin van der Grinten1

Introduction

Eastern gamagrass [Tripsacum dactyloides (L). L.] is a native perennial, productive and

digestible warm season grass being used for forage production. It can be used in areas of low pH

and will provide better forage production than cool season grasses and legumes during hot dry

summers. It is longer lived than most forage legumes. Eastern gamagrass establishes slowly and

competes poorly the first year with annual grasses and broadleaf weeds. It is frequently sown in

30-36 inch rows with a corn planter to facilitate mechanical harvest, this allows space for weed

proliferation. This row spacing and the inherent slow first year growth prevent canopy closure

until the second year. Eastern gamagrass requires a herbicide to reduce weed competition for

consistent successful establishment. Follow up weed control for annual and perennial weeds may

be necessary the second year depending on the density of the planting.

Eastern gamagrass is tolerant to many herbicides used in corn production. Dicamba and 2,4-D

are labeled for pastures and hayland but no residual herbicides are registered for use on annual

grasses. A study by Fick (1995) compared preemergence applications of Ally (metsulfuron),

Glean (chlorsulfuron), Pursuit (imazethapyr) and Arsenal (imazapyr) on eastern gamagrass. Ally

is labeled for broadleaf control in pastures and Glean is labeled for broadleaf control in small

grain. There was no seedling density reduction found with these 2 products at their highest rates

tested 48 g ha-1 and 120 g ha-1 respectively. The Pursuit and Arsenal are in the imidazolinone

(IMI) family, there was a stand reduction with the 35 g a-1 rate during a dry year. The following

year the eastern gamagrass tolerated the IMI herbicides at 140 g a-1 but grass weeds were not

controlled at that rate. This study compares two, new, low rate corn herbicides with good

annual grass control, Accent (nicosulfuron) (Dobbels and Kapusta 1993; Mekki and Leroux 1994),

and Basis (rimsulfuron) (Mekki and Leroux 1994) with Plateau (imazapic) a herbicide for native

prairie restoration (Becker and Miller 1998) and a few standard corn herbicides. A spray chamber

study was also conducted comparing Accent, Basis and Plateau herbicides postemergence on

eastern gamagrass.

Material and Methods

Field Study

The study was conducted at the USDA-NRCS Big Flats Plant Materials Center in Corning New

York (42o 07’N and 76o

 57’ W, 271-m elevation). “Pete” eastern gamagrass was planted on

5/22/97 after 8 weeks of stratification using a Tye drill with 32 inch row spacing. The seed was

planted at 7.8 lbs ac-1 PLS. The soil type was a deep well-drained Unadilla silt loam, (Typic

Dystrochrepts). Soil test indicated a pH of 6.3, with 3.2% organic matter, high P and moderate K.

No fertilizer was applied. The herbicide was sprayed with a bicycle mounted compressed air

sprayer at 2 mph, with 25 gallons of water ac-1 at 40 psi, 20 inches above the surface using

nozzle 8002. The preemergence spray was done on 6/5/97 and the postemergence on 6/23/97.

A nonionic surfactant at 1.0% v v-1 was applied for postemergence applications. The gamagrass,

pigweed [Amaranthus viridis L.], lambsquaters [Chenopodium album L.], and foxtail [Setaria spp]

were 2-4 inches tall at the time of postemergence spraying. The gamagrass was at the 2-4 leaf

stage. Bladex was applied preemergence to the Banvel and 2,4-D postemergence treatments to

 

1 USDA-NRCS Big Flats Plant Materials Center, Box 3266A, State Route 352, Corning, NY

14830.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

306

control annual grasses. The control was hand weeded on 6/27/97. The herbicides, application

rates, and timing are listed in Table 1a. The plot size was 10 x 25 ft with 4 rows of gamagrass

being sprayed. There were 4 replications per herbicide treatment.

Evaluations were conducted on 7/2/97 to determine gamagrass population and leaf height (cm).

Three 2-meter rows were counted per replication for population. The height (cm) was measured

as leaf length of the tallest leaf on 10 plants per replication. On 8/20/97 average tiller number of 5

plants per replication, a visual weed rating, and a leaf length on 5 plants per replication were

measured. On 10/15/97 15 plants were dug up, dry weight of tops was measured for each

replication and leaf number was counted on 7 of those plants.

Spray Chamber Study

“Pete” eastern gamagrass was planted after an 8 week stratification on 3/31/97 in metromix. The

seeds were planted in 65-celled, 7.5 by 13.5 inch Rootrainers. There were three replications per

treatment. An Allen track spray chamber was used with a 20 gallon ac-1 rate of water, at 35 psi

with an 8001 nozzle sprayed 20 inches above the canopy. The herbicides and application rates

are listed in Table 2. The plants were sprayed postemergence on 4/25/97 at the 3 leaf stage.

They were grown in a greenhouse then evaluated for plant height and leaf number on 5/5/97. A

final visual evaluation was made on 6/6/97.

Results and Discussion

Field trial

The weed control was not as effective as expected for the preemergence herbicides except for

Bladex which worked excellently. This may have been due to a lack of rainfall for 7 days following

spraying. The Bladex and the Bladex plus Banvel (post) and Bladex plus 2,4-D (post) had the

best weed control in the study with 12.5, 11.7 and 35% weed cover when evaluated on 10/15/97.

The control plots were hand weeded resulting in 55% cover when evaluated on 10/15/97. This

was similar in percent cover to the other herbicide treatments.

Since the test germination of the seed lot was low (20%), 39 lbs ac-1 of bulk seed was planted. A

high average population was achieved due to a germination rate much higher than the test

results. The population for Dual treatment was significantly lower (30.0 plants 2 m-1) than the

Atrazine (39.0), Bladex (39.0) and control treatments (37.0). No plants were lost from the

postemergence sprays. The Banvel treatment which followed a preemergence spraying of

Bladex had a significantly lower population (29.0) than the control and Bladex alone although no

mortality was observed from the Banvel.

The Plateau preemergence treatment caused some phytotoxicity especially at the 8 oz ac-1 rate.

This was characterized by yellowing, necrosis, delayed emergence, and stunting. This was

apparent when looking at the tiller number (2.0) and tolerance rating (4.6) when compared to the

control and Bladex tiller number (3.8 and 5.0) and tolerance rating (1.0 and 1.6) respectively. The

Dual treatment also resulted in yellowing and stunting, this was shown by a low tiller number of

3.2 and a tolerance rating of 4.0.

There was some yellowing from all of the postemergence sprays but the plants recovered well

with final dry weights not statistically different P<0.05 than the control. The Accent and Basis

treatments were not significantly different than the control for tiller number or leaf number. The

dry weights per 15 plants for the Accent, Basis (0.33 oz ac-1) and Plateau were not statistically

different (P<0.10) than the control (47.1 g) but were less than Bladex (74.0 g). The Basis 0.66 oz

ac-1 rate resulted in the highest dry weight (78.4 g). There were no significant differences for leaf

height for any of the treatments. See Tables 1a and 1b for a summary of the data for the field

trial.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

307

Spray Chamber Study

The spray chamber study compared postemergence spraying of Accent, Basis and Plateau with a

control. The Plateau herbicide resulted in severe injury to the gamagrass seedlings at all rates.

There were significantly fewer and shorter leaves with Plateau treatments at all rates compared

with the control (Table 2). The 12 oz ac-1 rate resulted in 0% survival. The Accent and Basis

showed some chlorosis but had no effect on plant height, leaf number, or vigor.

Conclusions

The Plateau herbicide, post emergence, at all rates was phytotoxic to eastern gamagrass. When

Plateau was sprayed preemergence at the 8 oz ac-1

 rate; stunting, delayed emergence, chlorosis,

and necrosis was observed. Dry weight was among the lowest in the trial at both the 4 and 8 oz

rate but was not statistically different than the control. Additional trials at the 4 oz ac-1

 rate is

warranted. Dual, when sprayed preemergence, significantly reduced the stand. Accent, Basis,

Banvel, and 2,4-D, when sprayed post emergence, caused some chlorosis early which was

outgrown and had no significant effect on final biomass. The Basis herbicide treatment (0.66 oz

ac-1

) resulted in the highest dry weight measurement in the trial. The Atrazine, Bicep and Bladex

treatments performed well with no apparent phytotoxicity.

References

Becker, R.L and D.W. Miller. 1998. Warm season grass establishment systems. Proc. of the

Western Society of Weed Sci. 51:127-128.

Dobbels, A.F. and G. Kapusta. 1993. Postemergence weed control in corn (Zea mays) with

nicosulfuron combinations. Weed Technology 7:844-850.

Fick, W. H. 1995. Eastern gamagrass tolerance to four preemergence herbicides. Proc. North

Central Weed Control Conf. 50:113-114.

Mekki, M. and G.D. Leroux. 1994. Activity of nicsulfuron, rimsulfuron, and their mixture on field

corn (Zea mays), soybean (Glycine max), and seven weed species. Weed Technology 8:436-

440.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

308

TABLE 1a Eastern Gamagrass Herbicide Field Study

 10/15/97 10/1/97 8/20/97 7/2/97 7/2/9

Herbicide Rate ac-1 DW1 leaf # % Weeds Tiller # Tolerance2 Plants 

Accent 1x (Post) 0.66 oz 39.9 22.0 56.3 3.5 3.3 Accent 2x Post) 1.32 oz 45.6 22.5 67.5 4.1 4.5 Atrazine (Pre) 1.8 lb 65.6 27.3 75.0 4.3 1.6 Banvel (Post) 1.0 pt 54.0 22.8 11.7 3.0 3.6 Basis 1x (Post) 0.33 oz 55.7 24.0 65.0 4.7 4.3 Basis 2x (Post) 0.66 oz 78.4 24.8 75.0 4.2 4.8 Bicep (Pre) 3.0 qt 51.2 24.8 68.8 4.2 2.3 Bladex (Pre) 2.25 qt 74.0 24.5 12.5 5.0 1.6 Control 47.1 18.5 55.0 3.8 1.0 Dual (Pre) 2.5 pt 45.5 20.5 61.3 3.2 4.0 Plateau 1x (Pre) 4 oz 40.8 20.0 72.5 2.9 3.5 Plateau 2x (Pre) 8 oz 41.1 19.8 87.5 2.0 4.6 2,4-D (Post) 2.0 pt 43.2 23.3 35.0 3.3 2.6 LSD.05 23.73 34.6 1.26 1.9 

P 0.09 0.34 0.0008 0.0015 0.0015 0.01

1 gram weight of 15 plants, 2 1 = best 9 = worst, 3 LSD0.10
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309

TABLE 1b Eastern Gamagrass Herbicide Field Study

7/2/97 7/2/97 8/20/97 8/20/97

Herbicide Rate ac-1 ht (cm) weed rating1 ht (cm) weed rating1

Accent 1x (Post) 0.66 oz 12.4 4.5 36.2 5.6Accent 2x Post) 1.32 oz 11.8 5.8 39.0 4.9Atrazine (Pre) 1.8 lb 13.3 1.3 40.1 5.3Banvel (Post) 1.0 pt 10.8 1.3 30.8 1.0Basis 1x (Post) 0.33 oz 12.3 2.8 35.2 4.3Basis 2x (Post) 0.66 oz 10.6 3.3 36.0 4.5Bicep (Pre) 3.0 qt 12.3 1.7 38.1 3.3Bladex (Pre) 2.25 qt 13.1 1.1 36.6 1.4Control 12.2 1.0 35.4 3.8Dual (Pre) 2.5 pt 10.9 3.5 33.2 3.8Plateau 1x (Pre) 4 oz 11.4 3.0 32.8 5.9Plateau 2x (Pre) 8 oz 10.1 3.3 33.3 5.02,4-D (Post) 2.0 pt 11.2 1.4 32.6 3.3 LSD.05 1.6 2.0P 0.735 0.00001 0.650 0.00011 1 = best 9 = worst
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TABLE 2 Spray Chamber Study1

Herbicide Rate ac-1 Ht (cm) Leaf #

Plateau 4 oz 11.5 2.6

Plateau 8 oz 8.5 2.3

Plateau 12 oz 10.1 2.5

Accent 0.66 oz 22.6 4.1

Accent 1.32 oz 24.1 4.1

Basis 0.33 oz 23.1 4.0

Basis 0.66 oz 20.8 4.0

Control ****** 22.3 4.3

LSD.05 2.0 0.45

P 0.00001 0.00001

1) Sprayed 4/25/97, Evaluated 5/5/97
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

311

Chromosome Doubling and Mode of Reproduction of Induced Tetraploids

of Eastern Gamagrass

Paul R. Salon1 and Elizabeth D. Earle1

Abstract

Eastern gamagrass, [Tripsacum dactyloides (L.) L.] is a perennial, warm season grass that is

being developed as a forage. Shoots were derived from callus initiated from immature embryos

and immature inflorescences of diploid (2n=2x=36) gynomonoecious eastern gamagrass.

Gynomonoecious plants have the potential to increase seed production twenty fold. These

shoots were induced to microtiller in the presence of 3 mg l-1 of benzyladenine (BA).

Amiprophosmethyl (10, 15, or 20 μM) was applied to 27 microtillers for 3 to 5 days to induce

chromosome doubling. All 14 surviving plants were tetraploid, (2n=4x=72), as determined by flow

cytometry or chromosome counts. These plants were morphologically normal and produced seed.

Test crosses were made with a known diploid. Flow cytometry and chromosome counts showed

that the progeny were triploid, proving the induced tetraploids reproduce sexually. Naturally

occurring tetraploids are apomictic, monoecious, more robust, and less winter hardy than

diploids. We are interested in using these sexual tetraploids to increase biomass, winter

hardiness and seed production of eastern gamagrass for the Northeast.

Salon, P.R. and E.D. Earle. 1998. Chromosome doubling and mode of reproduction of induced

tetraploids of eastern gamagrass (Tripsacum dactyloides L.). Plant Cell Reports 17:881-885.

 

1 USDA-NRCS Big Flats Plant Materials Center, Corning, NY and Cornell University, Ithaca, NY
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

312

Beach Dune and Critical Area Stabilization with Native Plants

Samuel Sanders and USDA NRCS Florida Plant Materials Center Staff1

Abstract

Each year thousands visit the sandy white beaches along the Gulf of Mexico, including John

Beasley Park in Okaloosa County, FL. Construction of this park, located near Ft. Walton, began

in 1992. The Plant Materials Specialist and the Plant Materials Center were requested to assist

in the establishment of vegetation around the newly installed pavilion and several adjacent

blowout areas. The dunes at Beasley Park were almost completely devoid of vegetation, and

subject to severe erosion. In 1993 the PMC, working in cooperation with the local SWCD, the

County, the RC&D Council and numerous volunteers from various agencies began revegetation

effort of this new park.

Among the plant species used to revegetate the areas were four varieties released from the

Brooksville PMC: ‘Northpa’ and ‘Southpa’ bitter panicum [Panicum amarum Elliott], ‘Sharp’

marshhay cordgrass [Spartina patens (Aiton) H.L. Muhl.], and ‘Flora Sun’ beach sunflower

[Helianthus debilis Nutt.]. The effort took several years (1993 – 1996) to be completed. All of the

above plants were established using vegetative transplants propagated at the PMC. The project

was fertilized and irrigated.

Beasley Park has been in the direct path of several tropical storms, Hurricane Opal in 1995 and

Hurricane George in 1998. Opal’s strong winds destroyed over 125 miles of primary dune system

along the northwest Florida Gulf coastline. Primary and secondary dunes in Beasley Park were

still intact after the storm. Marshhay cordgrass and bitter panicum had a 95% survival rate. The

beach sunflowers were severely burnt but recovered.

‘Northpa’ bitter panicum is being used extensively by the US Army Corp of Engineers in a 25-mile

beach dune revegetation project in North Carolina. The project leader reports that it has had a

92% survival rate and is out-performing sea oats. Though it is a coastal plant, bitter panicum also

performs well on critical area sites inland. Eglin Air Force Base, near Pensacola, is revegetating

several borrow pit sites. Erosion from these pits was causing sedimentation in the streams where

the endangered Okaloosa darter is found, further threatening the existence of this species.

Native species, which could colonize in dry, sterile soils and establish rapidly, were preferred.

‘Northpa’ and ‘Southpa’ were able to fit these requirements, and are successful on these sites.

 

1 14119 Broad Street, Brooksville, FL 34601, 2

 Plant Material Specialist, P.O. Box 141510

Gainesville, FL 32614-1510
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

313

Development of Direct Seeding Techniques to Restore Native Groundcover

in a Sandhill Ecosystem

Gregory S. Seamon1, Meryl J. Hattenbach2, Anne Cox3, and Doria R. Gordon3

Abstract

The Nature Conservancy’s Apalachicola Bluffs and Ravines Preserve was a windrowed slash

pine plantation until it was selectively logged in the mid 1980’s. Since then restoration has been

underway and has included planting longleaf pine [Pinus palustris Mill.] and wiregrass [Aristida

beyrichiana Trin. & Rupr.] plugs by hand. This method of restoring groundcover is limited by the

on-site nursery’s capacity to restore only 5 acres of groundcover annually. Methods of directly

seeding native groundcover species are needed to efficiently restore over 2500 acres of sandhill

on the preserve. Direct seeding trials were initiated in 1994. Attempts at sowing a mixture of

seed with a shaker fertilizer spreader and a conical fertilizer spreader were unsuccessful. A third

attempt using a leaf blower adequately spread the seed but resulted in minimal seedling

establishment. Wiregrass seedlings were successfully established in 1995 using a leaf blower to

sow seed on a bulldozed site. In 1996 wiregrass seedlings were successfully established by

sowing with a hay blower in a harrowed site. In January 1997, windrows were bulldozed and

smoothed so that all existing vegetation was removed. Plots were established in the bulldozed

area and then seeded with a mixture of wiregrass and other native seed. Control plots were

established which were bulldozed but otherwise untreated. Treatments were applied in a

randomized complete block design for sowing native seed alone or with winter rye, rolling the

seed in or not following sowing, and watering for the first four months after seeding or no

watering. Monitoring conducted in September 1997 showed high species richness in all study

plots. Rolling seed in immediately after sowing increased wiregrass seedling establishment and

survival. This direct seeding method successfully restored wiregrass and other understory

species and was considerably less expensive and more efficient than planting plugs. The

experimentation has continued with methods of site preparation for sowing seed in 1999 including

prescribed burning and roller chopping. In addition various other types of equipment have been

used for seeding, including a different type of hay blower, a modified fertilizer spreader, and a

hydroseeder.

 

1

The Nature Conservancy, Northwest Florida Program, P.O. Box 393, Bristol, FL 32321, phone

(850) 643-2756, fax (850) 643-5246, email: acox_nettally.com. 2

Indiana Dunes National

Lakeshore, 1100 N. Mineral Springs Road, Porter, IN 46304, phone (219) 926-7561. 3

The

Nature Conservancy, Department of Botany, P.O. Box 118526, University of Florida, Gainesville,

FL 32611-8526, phone (352) 392-5949, email: dgordon@tnc.org.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

314

Production and Nutrient Uptake by Native Warm-Season Grasses

K.W. Staver1

Warm-season grasses are being widely promoted in Maryland through the Conservation Reserve

Program to enhance wildlife habitat and reduce nonpoint source pollution from agriculture.

Switchgrass [Panicum virgatum L.] rooting depth can exceed 3 m (Moser and Vogel 1995), and

nitrogen (N) isotope studies have indicated its ability to transport N into above ground tissue from

below a depth of 1.2 m (Huang 1994). This suggests that these grasses may be useful in riparian

settings for attenuating subsurface nitrate loads from up-gradient source areas.

There also is interest in the potential for using warm-season grasses as biofuels. Switchgrass is

considered to have potential for use as feedstock in ethanol production (Cherney et al. 1991;

McLaughlin 1992) as well as fuel in direct combustion applications (Downing et al. 1995). Warmseason grasses are known for their ability to thrive on low-fertility sites and have the potential for

producing large quantities of biomass per unit of plant nutrient. However, little information

presently exists on their nutrient uptake and retention capacity in high-fertility settings where they

are currently being planted in Maryland. The primary objectives of this study were to evaluate the

biofuel potential and nutrient uptake capabilities of switchgrass and eastern gamagrass

[Tripsacum dactyloides (L.) L.] under high nutrient loading rates.

Approach

This study was conducted at the Wye Research and Education Center in Queen Anne’s County,

Maryland. The study site is nearly level with soils classified primarily within the Matapeake and

Mattapex Series (fine-loamy, mixed, mesic typic/aquic Hapludults) which are moderately welldrained and widely used for grain production on the Maryland Eastern Shore. The soil surface at

the study site is approximately 6 m above sea level and the water table is located at a seasonally

variable depth from 2 to 4 m below the soil surface.

Twelve plots (30 m x 25 m) each of eastern gamagrass and switchgrass (Kanlow) were planted in

1996. Eastern gamagrass was planted in 76 cm rows and switchgrass drilled in 38 cm rows. No

nutrients were applied to any plots during 1996 or 1997. In April 1998 all plots were cut and

baled prior to onset of spring growth. On June 2, new growth in all plots was cut to a height of 15

cm and removed to facilitate even application of poultry litter. Poultry litter was surface applied on

June 8 at 0, 6.7, and 13.4 Mg ha-1. The poultry litter contained 4% N and 1.4% phosphorus (P),

and 1.9% potassium (K), resulting in N application rates of 0, 269, and 538 kg ha-1, P application

rates of 0, 94, and 188 kg ha-1, and K applications rates of 0, 127, and 255 kg ha-1.

Nitrate leaching was monitored in the plots continuously using gravity lysimeters installed at a

depth of 60 cm. Above-ground dry matter and nutrient content were measured in early September

1998 by collecting 2 m row sections from each plot. All remaining 1998 above-ground growth

was cut, baled, and weighed in early April 1999 just prior to the onset of new growth. Bales from

each plot were subsampled to determine tissue nutrient content. Switchgrass subsamples also

were sent to the Federal Energy Technology Center in Pittsburgh for analysis of combustion

characteristics.

Results and Discussion

Approximately 2.0 tons acre-1 of 1997 growth was harvested from both eastern gamagrass and

switchgrass plots in April 1998. An additional 1.5 ton acre-1 of new growth was removed on June

2, 1998, just prior to application of poultry litter. All plots receiving poultry litter showed an

 

1

 University of Maryland, College of Agriculture and Natural Resources, Wye Research and

Education Center, P.O. Box 169, Queenstown, MD 21658
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

315

obvious growth response, apparently in response to increased N availability, since soil P and K

levels were adequate for maximum production prior to poultry litter applications. Above-ground

dry matter in early September 1998 in the 13.4 Mg ha-1 poultry litter plots was 7.4 and 11.6 Mg

ha-1 in the eastern gamagrass and switchgrass treatments, respectively, approximately double

the dry matter levels measured in the control plots (Table 1). By early April 1999, above ground

dry matter had decreased in all treatments, with the greatest reductions (37.5 %) occurring in the

treatments where 13.4 Mg ha-1 of poultry litter had been applied. The late summer to spring

comparisons must be viewed with caution since small subsamples were collected in September

versus whole-plot harvesting in April. Aboveground biomass in the Eastern gamagrass plots was

approximately 40-50% less than in switchgrass plots receiving the same poultry litter applications.

Tissue N and K levels tended to be higher in the Eastern gamagrass plots relative to comparable

switchgrass plots in late summer and concentrations of both nutrients tended to increase with

increasing poultry litter application rates (Table 1). Total uptake of N and K was higher in

switchgrass plots due to higher biomass production. Late summer tissue P concentrations were

similar in all treatments at approximately 0.2% (dry mass basis). By April 1999, tissue

concentrations of all plant nutrients had decreased, although to a widely varying degree. Tissue

N concentrations in the switchgrass plots decreased approximately 25% from September through

April to an average for all plots of 0.47%. In the eastern gamagrass plots the decrease in tissue

N averaged 14%, and average spring concentrations were 0.67%. It is not clear whether these

reductions were due to loss of N from tissue or were due to a disproportionate loss of N-enriched

tissue (leaves versus stems) during winter or harvesting. In the case of P and K, which tend to be

present in plant tissue in forms that are readily leached when cell membranes lyse, much larger

reductions in tissue concentrations occurred between September and April. In both eastern

gamagrass and switchgrass treatments, tissue P concentrations decreased between 60 and 70%

from September to April. During the same period decreases in tissue K concentrations averaged

85% in the switchgrass treatments and 90% in the Eastern gamagrass treatments. Tissue

carbon concentrations in both fall and spring in all tissue samples were approximately 45% on a

mass basis.

The loss of large fractions of tissue nutrients from fall to spring greatly reduced nutrient removal

rates in harvested biomass. Although higher biomass yields were achieved with fall harvesting,

the quantity of biomass harvested per unit of plant nutrient tended to be much higher in the

spring. In the switchgrass high poultry litter application treatment plots, total N uptake into aboveground tissue was equivalent to approximately 44% of the plant available N (approximately half of

the total N) supplied by the poultry litter (15 kg N Mg-1). P uptake in the same treatment was

equivalent to only 12% of the total quantity applied, while for K total uptake was equal to 52% of

that applied in the poultry litter. By spring, the imbalance was even more pronounced. Although

N removal in the switchgrass harvested from the high poultry litter treatments dropped to only

18% of applied plant available N, the sharp decreases in tissue P and K levels reduced removal

rates in harvested biomass to less than 3 and 5% of the P and K applied, respectively.

Although only a minor fraction of the total N applied in poultry litter was accounted for in aboveground biomass, nitrate leaching patterns indicated that pore-water nitrate concentrations in the

upper regions of the soil profile (0-60 cm) remained low. Nitrate leaching was minimal (<3 kg ha-1

nitrate-N yr-1) in all plots from when the grasses were planted in 1996 through the spring of 1998.

Despite the poultry litter applications in June 1998, leachate nitrate-N concentrations during the

following winter remained below 1 mg L-1 in all plots until late February when average

concentrations briefly exceeded 1 mg L-1 in the two poultry litter treatments. By early April 1999

average leachate nitrate-N concentrations had decreased to approximately 0.5 mg L-1, similar to

concentrations in the control treatments.

The spring harvested switchgrass had a heating value of 17.8 MJ kg-1 (7660 Btu lb-1) and a total

ash content of 2.05%. The primary constituents in the ash were SiO2 (57.1%), CaO (12.6%), K2O

(6.9%), MgO (5.7%), Fe2O3 (5.5%), and Na2O (3.7%). The heating value is similar to those

generally reported for summer harvested switchgrass, but the total ash content is lower (Johnson
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

316

et al. 1995). The loss of a large percentage of tissue K during winter months reduced the alkali

index to a range that suggests a low potential for fouling problems during combustion (Jenkins et

al. 1998).

Conclusions

Switchgrass and eastern gamagrass production can be approximately doubled with surface

applied poultry litter, primarily in response to increased N availability. Under a single cut

management system, switchgrass produces more above-ground biomass per unit of N and K, but

P utilization is similar. Although only a small fraction of total N applied in poultry litter was

accounted for in above-ground production of both grasses, nitrate leaching was minimal,

suggesting that major quantities of N were sequestered in below-ground biomass. Delaying

harvest until early spring caused only moderate reductions in total biomass yield, but major

reductions in tissue nutrient concentrations. This resulted in retention of P and K in the soil

system and an improvement of the suitability of the harvested biomass for fuel in direct

combustion applications. In a spring harvest management system, poultry litter applications (high

rate) would only be necessary every 20 to 30 years to replace P and K removed in harvested

biomass, while annual applications would likely be needed to prevent reduced production due to

N availability. Even with harvesting during the growing season, only a small fraction of the P

supplied in poultry litter is removed with harvest. Consequently, using poultry litter to supply N or

K requirements of an intensively managed grass system would result in a rapid increase in soil P

levels.

The tendency for N-limitation of production suggests that both switchgrass and eastern

gamagrass could be highly effective in retaining N in riparian settings where nitrate is supplied via

subsurface flow from up-gradient cropland. The critical question is how effectively these grasses

are able to utilize nitrate moving through riparian areas in subsurface flow. If nitrate is accessible,

relatively high production could be maintained with minimal inputs of P and K by delaying harvest

until late winter or early spring. Higher short-term yields could be achieved with multiple harvests

during the growing season but soil reserves of P, and especially K, would be more rapidly

depleted. In the no-harvest/no-fertilizer situation mandated for grass buffers installed under the

Conservation Reserve Program, it is likely that N retention would remain effective for many years

due to the potential for grasses to sequester large quantities of carbon in the soil profile.

References

Cherney, J.H., K.D. Johnson, J.J. Volenec, and D.K. Greene. 1991. Biomass potential of selected

grass and legume crops. Energy Sources 13: 283-292.

Downing, M., S. McLaughlin, M. Walsh. 1995. Energy, economic and environmental implications

of production of grasses as biomass feedstock. p. 288-297. In Proceedings Second Biomass

Conference of the Americas: Energy, Environment, Agriculture, and Industry. National Renewable

Energy Laboratory. Golden, CO.

Huang, Y. 1994. Nitrate removal from soils overlying a contaminated surficial aquifer. Ph.D.

Dissertation. South Dakota State University, Brookings, SD.

Jenkins, B.M., L.L. Baxter, T.R. MIles, Jr., and T.R. Miles. 1998. Combustion properties of

biomass. Fuel Processing Technology 54: 17-46.

Johnson, D.K., P.A. Ashley, S.P. Deutch, M. Davis, J.A. Fennel, and A Wiselogel. 1995.

Compositional variability in herbaceous energy crops. p. 267-277. In Proceedings Second

Biomass Conference of the Americas: Energy, Environment, Agriculture, and Industry. National

Renewable Energy Laboratory. Golden, CO.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

317

McLaughlin, S.B. 1992. New switchgrass biofuels research program for the southeast. p. 111-

115. In Proceedings of Annual Automobile Technology Development Contractor’s Coordination

Meeting, Dearborn, MI. Nov. 2-5, 1992.

Moser, L.E. and K.P. Vogel. 1995. Switchgrass, Big Bluestem, and Indiangrass. p. 409-420. In

R.F. Barnes, D.A. Miller, C.J. Nelson, (eds.) Forages Vol. 1, An Introduction to Grassland

Agriculture. Iowa State University Press, Ames, IA.

Table 1. Above-ground biomass production and nutrient content of switchgrass and eastern

gamagrass on September 10, 1998 and April 14, 1999 as affected by differing rates of surfaceapplied poultry litter (PL).

Treatment Biomass Nitrogen Phosphorus Potassium

Kg ha-1 % kg ha-1 % Kg ha-1 % Kg ha-1

Switchgrass

Sept-10-98

Control 5394 0.57 31.1 0.20 10.7 0.89 47.5

 6.7 Mg PL ha-1 8804 0.59 52.6 0.17 15.5 0.86 77.6

13.4 Mg PL ha-1 11600 0.74 88.3 0.19 21.9 1.14 132.7

April-14-99

Control 5098 0.46 23.3 0.06 3.2 0.14 7.3

 6.7 Mg PL ha-1 6521 0.47 31.1 0.06 4.0 0.12 7.6

13.4 Mg PL ha-1 7382 0.48 35.0 0.07 5.1 0.17 12.2

Eastern Gamagrass

Sept-10-98

Control 3596 0.70 25.3 0.18 6.2 1.26 45.2

 6.7 Mg PL ha-1 4873 0.78 38.1 0.19 9.2 1.33 65.2

13.4 Mg PL ha-1 6844 0.88 60.1 0.20 13.8 1.61 110.9

April-14-99

Control 2536 0.62 15.8 0.06 1.4 0.09 2.2

 6.7 Mg PL ha-1 3968 0.68 26.9 0.07 2.8 0.14 5.5

13.4 Mg PL ha-1 4350 0.72 31.5 0.08 3.6 0.20 8.9
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

318

Mid Atlantic Region Grass Collections Efforts at the University of Maryland

in Support of the NRCS-PMCs

Harry Jan Swartz, Gwen Meyer, Jennifer Kujawski, Norman Melvin, John Englert,

Chris Miller, Bill Skaradek, and Valerie Hopkins1

Collections

Over the last half of this decade, seed of perennial native Piedmont and Coastal Plain

Mid-Atlantic States grasses has been intensively collected for use in environmental restoration

projects. These efforts have been designed to develop regional grasses as few NRCS grass

releases have originated here. Seed is being imported from the Midwest, thereby contaminating

our natives. The University of Maryland has aided the NRCS-Plant Materials Centers (PMC) in

these collections and with research on their culture.

From 1996, over 180 accessions of 30 species have been harvested (>100 lbs of seeds in total).

Collections have been in pristine areas such as from forest clearings near back bays and ocean

estuaries, from river scours, from xeric or impoverished locations, from clayey beds, on armed

services fortifications or governmental installations, and under power lines and right of ways kept

grassy by constant mowing or herbicide use. Seed collections were planted at two University of

Maryland farms (Queenstown and Antietam) for initial evaluation and increase. Over a half-acre

of seed producing native grasses are now being managed for the NRCS. Resulting plants and

seed were also planted at the Beltsville, MD and Cape May, NJ Plant Material Centers for

evaluation and production of composite selected releases. Throughout our collections, these

warm season grasses were never observed as agricultural pests.

The “big four” grasses of Midwestern tall grass prairies, are found in the Mid-Atlantic; however,

big bluestem [Andropogon gerardii Vitman] (2 collections) is comparatively rare here. Our largest

collection was near the C&O Canal just outside of Washington DC. As feed for draft animals was

commonly transported along the canal; it is questionable whether this material is exotic or native.

By contrast, Indiangrass [Sorghastrum nutans (L.) Nash] (15 collections) is relatively easy to

establish and it was found everywhere.

Switchgrass [Panicum virgatum L.] (12 collections) is more common on the coastal plain but is

found throughout the region in the wettest to driest upland sites. It can be too aggressive in mixed

plantings and should be planted in occasional solid stands. Plateau residual herbicide selectively

controls most weeds in our grass collections but can hurt switchgrass. Separating plantings of

solid switchgrass seedings from a Mid-Atlantic grass mix plantings would allow the use of

moderate to high concentrations of Plateau away from the switchgrass.

Little bluestem [Schizachyrium scoparium (Michx.) Nash] (14 collections inc. coastal bluestem

[Schizachyrium scoparium var littoralis (Nash) Gould] can also be established well with the use of

Plateau. The fluffy seed it produces can be processed for seeding. We have been quite

successful establishing plants in areas overspread in the fall with little bluestem straw. Most

collections were made along the coast and in sandy, poor soils in the Pine Barrens of NJ and VA

and on the sandy areas near the ocean. One collection from a clayey bottom in N VA (ACC #

9080068) was noticeably different.

 

1

Natural Resource Conservation Service, Plant Material Centers and University of Maryland

Department of Natural Resource Sciences and Landscape Architecture. This research supported

by contract from the Wetland Science Institute, USDA. The authors express their gratitude,

particularly to the foresight of its director, Dr. Billy Teels.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

319

Our native savannas commonly contain other grasses. Purpletop [Tridens flavus (L.) Hitchc.] (8

collections) naturally introduces itself in many upland grassy areas and can flower in the first year

from seed. Eastern gamagrass [Tripsacum dactyloides (L.) L.] (12 collections) grows well in

wetland and upland conditions. Dark brown eastern gamagrass seed tend to have viable

embryos; light colored ones are empty. These can be separated in water. Dry eastern

gamagrass seed benefits, on occasion, from 3-10 minutes sulfuric acid scarification and

subsequent moist stratification.

Less common grasses add to our diversity. We have had some establishment of broadcast Split

Beard Bluestem [Andropogon ternarius Michx.] (2 collections); however, we did not “clean” these

fluffy seeds. When we plant small quantities of fluffy seed, we rototill, rake, and roll over the

seed, usually with a vehicle. Beaked panicum [Panicum anceps Michx.] (10 collections)

establishes slowly, but by the second year, is quite noticeable. By contrast, Florida paspalum

[Paspalum floridanum Michx.] (7 collections) establishes rapidly the first year. Both grasses

tolerate mowing well.

Some wetland grasses were also collected. Bushy bluestem [Andropogon glomeratus (Walt.)

B.S.P.] (3 collections), Walter’s millet [Echinochloa waleri (Pursh) Heller] (1 collection), and giant

foxtail [Setaria magna Griseb] (1 collection) were harvested in occasionally inundated conditions.

Bushy bluestem from the southern range of this region tends to be much more vigorous and

ornamental. This vigor is maintained in common plantings. Giant foxtail, an annual, was

harvested in slightly brackish water inside a mature stand of Phragmites. Sugarcane plumegrass

[Saccharum giganteum (Walter) Pers.] (10 collections) and brown plumegrass [Saccharum

brevibarbe (Michx.) Pers. (4 collections) are the most spectacular of our native grasses. They are

established well from plug plants and can reach 10 ft in height. Our collection is being grown at

the Cape May NJ PMC.

Of the shade tolerant species, bottlebrush grass [Elymus hystrix L.] (3 collections) and slender

wildoats [Chasmanthium laxum (L.) H. O. Yates] (7 collections) grew in the deepest shade.

However, one collection of slender wild oats (ACC # 9080113) grew at least 500 feet from the

nearest tree. Virginia wild rye [Elymus virginicus L.] (18 collections) is easy to establish, tolerates

Plateau herbicide, and grew at the edges of forests and in cleared areas.

Smaller collections were made of prairie three awn [Aristida oligantha Michx.], arrowfeather

[Aristida purpurascens Poir.] and sand dropseed [Sporobolus cryptandrus (Torr.) A. Gray]. These

are being maintained in a greenhouse bed and as seed. Little barley [Hordeum pusillum Nutt.],

little foxtail [Alopecurus carolinianus Walter] and poverty oat grass [Danthonia spicata (L.) F.

Beauv.] were collected for possible use as “living mulches” or as winter cover in agricultural

situations. Each may be of use as companion species for restoration efforts. Of the three, little

barley is easy to culture; currently 0.1 acre is being cultured at the University of Maryland. The

NRCS National PMC has a more diverse collection.

Several of these species are being used to augment collections made by the Mid Atlantic PMCs.

Potential USDA-NRCS releases using these collections include: Indiangrass, little barley,

bottlebrush grass, Virginia wild rye, paspalum, beaked panicum, purpletop, and, perhaps,

switchgrass.

Research

Germination of most of the tall stature, freshly harvested native grasses is greatly aided by warm,

fluctuating temperatures (86-68oF) and moist prechilling (40oF) for around 6 weeks (see Table 1).

Light is not required for seed germination in most of these species; however, it helps.

Recommendations for a compact seedbed and seed drilling to a depth of one half to one inch is

appropriate. Cleaning the seed bed of excessive vegetation would seem important for obtaining

required fluctuating temperatures in early spring. In contrast, having bare ground could increase

the chance of poor germination due to insufficient moisture, especially in later plantings.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

320

Application of Plateau herbicide maintains competition free seedbeds. In comparison to repetitive

mowing, Plateau treated seed beds actually look like a warm season grass planting in their first

year of growth. Seed stored for longer periods (>1 year) does not seem to need stratification.

Finally, late harvested seed, i.e. after some shatter, generally germinated at higher percentages.

Possible companion cool season grass species were also investigated for use in initial soil

stabilization. Compared to red fescue [Festuca rubra L.] and tall fescue [Festuca arundinacea

Schreb.], red top [Agrostis gigantea Roth], and annual rye [Lolium multiflorum Lam.] permitted the

most growth of closely growing warm season grass plug plants. Native grasses potentially of use

as companion or establishment species, which sprout quickly and do not out compete the warm

season grasses, are Virginia wild rye, Florida paspalum, and little barley. Little barley is an early

fall planted annual with potential as a “living mulch” as it seeds and dries by June 15th. Planting

ratios for these species, in comparison to warm season grass seeding rates, need to be

established.

Visually, the success of a warm season grass prairie or savanna seems to require at least 10,000

to 20,000 plants per acre or one plant every 2 to 4 square feet. Establishment of more plants may

reduce the size of the individuals in the third and subsequent years, leading to little overall

difference in how the planting may be perceived. To test this, plug plants of various grasses were

planted in rows of increasing spacing the further away from the center of the rows. Six rows were

planted at 60 degrees to form an asterisk pattern to provide competition from other rows as well

as competition from the next plant in the row. Above ground dry weights of these grasses were

recorded after 2 years of growth. The data given in Table 2 indicate vigorous tall grass species

plants produce 10 times the above ground biomass if planted at the 9-inch” between-plant

spacing (listed as 22.5 inches from the center) as compared to 3-inch spacing. Thus, a thin

planting of these species will fill out in a relatively short period, in spite of large numbers of plants,

if other weeds are controlled. In the case of switchgrass grown in clay loam soil, a field with

700,000 plants (with 3-inch spacing) would produce 22 T per acre above ground biomass. A field

with 78,000 plants (9-inch spacing) would produce 18 T per acre. By the second year, little

difference in biomass is observed in the two widely varying plant densities; less variation would

be expected in subsequent years.

Table 1. Classification of native grass species by germination requirements. Number of weeks of

moist stratification in soil at 39oF required for germination is given in the parentheses.

Germination Requirements Grass Species

Fluctuating temperatures (86/68oF)

Light aids in germination

Beaked panicum (>6)

Indiangrass (6)

Switchgrass (6)

Purpletop (6)

Eastern gamagrass (6).

Enhanced germination in fluctuating

temperatures

Sugarcane plumegrass (6)

Brown plumegrass (6)

Not Sensitive to light or fluctuating

temperatures

Slender wild oats (6)

Annual rye(0)

Tall fescue (0)

Red fescue (0)

Florida paspalum(4).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

321

Table 2. Mean dry weight in grams of the above ground portion of warm season grass plants set

at various spacings in an asterisk shaped planting. Plants in the center, 3-inch, 7.5-inch, 13.5-

inch, and 22.5-inch away from the center are listed across the top distances. As there were six

lines of plants radiating from a single center plant, each distance was replicated six times in each

asterisk. Each asterisk was replicated three times at each site. The SL site had sandy loam soil

(Beltsville, MD) and the CL site had clay loam soil (Wye, Queenstown, MD).

Location in asterisk-distance from center

(Mean dry weight ft-2)

Species Site Center 3-inch 7.5-inch 13.5-inch 22.5-inch

Big bluestem SL 4 19 27 56 57

Big bluestem CL 17 22 27 69 92

Deertongue SL 6 9 16 34 77

Deertongue CL 11 6 19 42 61

Beaked panicum SL 7 6 18 22 33

Switchgrass SL 25 26 38 107 216

Switchgrass CL 26 30 60 130 221

Florida paspalum SL 22 18 33 73 133

Florida paspalum CL 20 31 54 119 302

Indiangrass SL 4 10 19 31 49
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

322

Improving Seedling Establishment by Modifying Seedling

Photomorphogenic Characteristics of Warm-Season Grasses

C.R. Tischler1, J.D. Derner1 and W.R. Ocumpaugh2

Panicoid (warm season) and Festucoid (cool season) grasses have different seedling

morphologies, which affect the dependability of establishment of these two types of grasses (Fig.

1). In both groups, the primary root (derived from the radicle in the embryo) is short-lived, and

must be replaced by adventitious roots arising at the crown node. In warm season grass

seedlings, the crown node is located near the soil surface, as the mesocotyl (or subcoleoptile

internode) elongates to bring the coleoptile tip to the soil surface. In cool season grasses, the

coleoptile itself elongates, thus keeping the crown node near planting depth. Hyder et al. (1971)

attributed the generally poor seedling establishment of blue grama [Bouteloua gracilis (Kunth)

Lag. ex Griffith] to so called “Panicoid” morphology. They also noted that in many blue grama

seedlings, the crown node is actually above the soil surface, where initiation and elongation of

adventitious roots is very unlikely. Olmsted (1941) and Tischler and Voigt (1987) made similar

observations for sideoats grama [Bouteloua curtipendula (Michx.) Torrey] and kleingrass

[Panicum coloratum L.], respectively.

Figure 1. Panicoid (warm-season) and Festucoid (cool-season) seedling morphologies. The

crown node is the site of origin of adventitious roots, which must develop to replace the primary

root if the seedling is to become established. Note the absence of an elongated mesocotyl in the

Festucoid seedling.

In warm season grasses, elongation of the mesocotyl ceases when the coleoptile tip receives

adequate (red light) stimulus (van Overbeek 1936). Although phytochrome is involved in sensing

the light signal, the sequence of events involved in converting the light signal into a cessation of

mesocotyl elongation is quite complex (Duke and Wickliff 1969; Vanderhoef et al. 1979; Parks

and Poff 1986).

Although the problem of crown node elevation is well described in the literature, Tischler and

Voigt (1993) were the first to propose a selection method to overcome the problem. They grew

 

1

 C.R. Tischler and J.D. Derner USDA-ARS, Grassland, Soil & Water Research Lab, 808 E.

Blackland Rd., Temple, TX 76502. 2

 W.R. Ocumpaugh Texas A&M University Agricultural

Research Station, 3507 Hwy 59E, Beeville, TX 78102.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

323

YDULRXVJUDVVHVLQORZFRQWLQXRXVOLJKW PROP-2 s-1) for 7 days, and observed that for many

grasses, there was considerable variation in crown node placement above the soil surface. The

use of low, continuous light circumvented complications arising because of different times of

emergence during normal day-night cycles. Tischler and Voigt (1993) proposed a recurrent

selection protocol in which seedlings with the least and greatest amounts of crown node elevation

are saved, crossed in the field, and allowed to produce seed. This seed is subsequently grown in

the low light environment to produce advanced populations of plants with low (LC) or elevated

(EC) crown nodes.

This paper describes the application of the Tischler and Voigt (1993) protocol to kleingrass and

switchgrass [Panicum virgatum L.] and the development and properties of the new germplasms.

Applications of this methodology to other species are discussed. Also, we argue for developing

native grass populations with altered photomorphological properties to facilitate establishment in

disturbed sites.

Methods

The cultivars ‘Selection 75’ kleingrass and ‘Alamo’ switchgrass were used as parental materials.

Three cycles of recurrent selection for low or elevated crown nodes were completed (see Tischler

and Voigt 1995 for details of plant culture). All polycross seed was produced in the field at

Temple, TX. Subsequently, populations of cycle 3 germplasm were established at College

Station, TX. The cycle 3 germplasm (EC-3 and LC-3) of each species was evaluated first in the

low-light environment in which selection was performed, and subsequently in various field

environments over two years. Additional work was performed with sorghum [Sorghum bicolor (L.)

Moench] inbreds and hybrids (using the low light system) to gain information about the

inheritance of crown node placement (Tischler et al. 1997).

Results

Selection for crown node placement was effective in kleingrass (when germplasm was evaluated

in low light), although most of the progress for lower crown node placement was made in the first

cycle of selection (Table 1). Shoot length was also modified, with EC-3 being greater than

Selection 75 which in turn was greater than that for LC-3. The standard deviations of node

elevations tended to parallel crown node elevation (as expected). The EC-3 population had the

greatest standard deviation of crown node elevation, indicating much genetic variability for this

trait was present.

Additional testing of parental and new kleingrass and switchgrass germplasms was performed in

complete darkness and at a number of different low light levels (Elbersen et al. 1998). In

darkness, coleoptiles of LC-3 seedlings were longer than coleoptiles of EC-3 seedlings. To

SUHYHQWFURZQQRGHHOHYDWLRQLQNOHLQJUDVVLQFRQWLQXRXVOLJKWOLJKWOHYHOVRIDQG!

mol m-2 s-1 were required for LC-3, Selection 75, and EC-3, respectively. Light threshold levels

required to stop mesocotyl elongation were lower for switchgrass. In LC-3 populations of both

kleingrass and switchgrass, rates of mesocotyl elongation were lower (in darkness) than for the

parental or EC-3 populations. These observations suggest that our selection protocol had acted

at several different physiological loci.

Although we were successful in selecting for the crown node placement in the low light system,

testing was needed to determine how the newly-developed germplasm would perform in the field.

The seed production blocks of EC-3, LC-3, and parental populations of both kleingrass and

switchgrass were very similar in appearance at the mature plant stage. Presently, we have

completed field evaluation of seedling establishment only for the switchgrass populations. Values

for various seedling parameters of field grown seedlings (averaged across experiments at

Stephenville, Beeville, and College Station, TX) are given in Table 2. While mesocotyl length and

crown node depth differed among the three populations, shoot length and leaf number were not
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

324

significantly different. This later result is important because in selecting for lower crown node

placement, there is a danger that one may also be selecting for slower growth rate.

Table 1. Crown node elevation and shoot length means and standard deviations (SD) of

selected and unselected kleingrass.

 Node Elevation Shoot Length

 ______________ _________________

Population Mean SD Mean SD

________________________________________________________________

 ---------------------------cm----------------------------------

EC-3 1.94 a1

 0.566 2.56 a 0.560

Unselected 0.87 b 0.443 2.36 b 0.551

LC-3 0.04 c 0.081 2.18 c 0.324

________________________________________________________________

1 Values within columns followed by the same letter are not significantly different at the 0.05

probability level.

Table 2. Crown depth, mesocotyl length, shoot length, and leaf number of Alamo, LC-3 and EC3 switchgrass at three locations in Texas in Summer, 1996.

________________________________________________________________

Genotype Crown Depth Mesocotyl Length Shoot Length Leaf Number

 ------------------------------cm-------------------------------

Alamo 0.34 ab1 0.84 a 8.87 a 4.5 a

LC-3 0.39 a 0.59 b 6.66 a 4.2 a

EC-3 0.28 b 0.91 a 9.02 a 4.4 a

________________________________________________________________

1 Values within a column followed by the same letter are not significantly different at the 0.05

probability level

Additional data was collected to determine the number of “loose” seedlings at Stephenville.

“Loose” seedlings were those that were poorly anchored to the soil, caused by seedlings being

held to the soil by only the primary root and in some cases one additional adventitious root.

There was a significant genotype effect for this phenomenon, with the following percentages of

poorly anchored seedlings: LC-3 14%, EC-3 38%, and Alamo 31% (p=0.05). A complicating

factor in this series of experiments is that seed mass of EC-3 and LC-3 was inadvertently

increased by the selection protocol (Elbersen et al. 1999). Values for seed mass [mg per 100

seed)] were Alamo (67), LC-3 (75), and EC-3 (76). Also, because only vigorous seedlings were

measured and saved in developing the cycle 3 populations, it is possible that we also

inadvertently selected for seedling vigor in EC-3 and LC-3. Observations supporting this

possibility were made for kleingrass by Young and Tischler (1994).
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

325

Elberson et al. (1999) unequivocally demonstrated that selection for crown node placement in the

low light system also modifies crown node placement in the field. Because rainfall was timely in

1996, Elberson et al. (1999) did not observe an effect of crown node placement on seedling

survival and establishment, as would be expected in drier years. However, their data on “loose”

seedlings support the hypothesis that lower crown node placement aids in seedling

establishment.

Because mass selection was used to develop the EC-3 and LC-3 populations, (and the grasses

are outcrossing and self-sterile), no information can be obtained concerning inheritance of crown

node placement. To address this question, we used sorghum inbred lines and their hybrids in

several experiments to quantify parental and hybrid crown node placement (Tischler, Voigt and

Monk 1997). Results of this study demonstrated that heterosis was not observed for crown node

placement in commercial sorghum hybrids, although seedling stage heterosis for other

characteristics is quite apparent (Table 3).

Table 3. Mesocotyl and shoot length of three groups of sorghum inbreds and their hybrids in low

light.

Entry Mesocotyl Length Shoot Length

 --------------------------------cm--------------------------------------

Group 1

Atx 399 (Inbred) 2.8 c1

 8.4 c

RTx2783 (Inbred) 3.2 a 9.3 b

Hybrid 3.0 b 10.0 a

Group 2

ATx2752 (Inbred) 2.9 a 8.2 b

RTx 430 (Inbred) 1.9 c 7.0 c

Hybrid 2.7 b 8.6 a

Group 3

ATx399 (Inbred) 3.0 a 8.1 b

RTx430 (Inbred) 1.9 b 7.0 c

Hybrid 3.0 a 10.2 a

________________________________________________________________

1 Values in a column and group followed by the same lower case level are not significantly

different at the 0.05 probability level.

Although heterosis for shoot length was observed in each of the three groups, mesocotyl length

never exceeded the high parent value. This indicates that factors controlling mesocotyl length

are under stringent genetic control, to prevent genetic interactions (heterosis) which could

negatively impact seedling establishment.

Conclusions

Experiments described here indicate that selection for crown node placement under low,

continuous light modifies the photomorphogenic responses of two species of Panicum under low

light, and in the case of switchgrass, under field conditions. We expect analogous field

responses for kleingrass. This selection system is economical while not being labor intensive

(Tischler and Voigt 1993). We advocate the use of this system to improve establishment of other

warm season grasses.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

326

At the present time, we are producing seed from cycle one EC and LC plants of sideoats grama.

The observations of Olmsted (1941) and our own observations (Tischler et al. 1997) suggest that

crown node placement in this species is detrimental to seedling establishment. In general,

seedling establishment characteristics of native prairie grasses need to be studied in more detail.

Seedling photomorphological traits have reached equilibrium in climax stands of vegetation.

Prairie restoration projects often take place on disturbed sites, or even on clean till sites where

conversion of marginal farmland to prairie is a management objective. Perhaps different suites of

photomorphological characteristics would be desirable under such clean seedbed situations. The

development of EC and LC populations of sideoats grama will allow us to determine

establishment characteristics of the populations on sites ranging from dense native prairie with

gaps (or safe sites) to clean till prairie restoration scenarios. The current interest in converting

marginal farmland to prairie underscores the importance of developing genetic and other

techniques to facilitate establishment of native grasses.

References

Duke, S.O. and J.L. Wickliff. 1969. Zea shoot development in response to red light interruption of

the dark-growth period. I. Inhibition of first internode elongation. Plant Physiol. 44, 1027-1030.

Elbersen, H.W., W.R. Ocumpaugh, M.A. Hussey, M.A. Sanderson and C.R. Tischler. 1998.

Crown node elevation of switchgrass and kleingrass under low light. Crop Sci. 38, 712-716.

Elbersen, H.W., W.R. Ocumpaugh, M.A. Hussey, M.A. Sanderson and C.R. Tischler. 1999. Field

evaluation of switchgrass seedlings divergently selected for crown node placement. Crop Sci. 39,

475-479.

Hyder, D.N., A.C. Everson, and R.E. Bement. 1971. Seedling morphology and seedling failures

with blue grama. J. Range Manage. 24, 287-292.

Olmsted, C.E. 1941. Growth and development in range grasses. I. Early development of

Bouteloua curtipendula in relation to water supply. Bot. Gaz. (Chicago) 102, 499-519.

Parks, B.M. and K.L. Poff. 1986. Altering the axial light gradient affects photomorphogenesis in

emerging seedlings of Zea mays L. Plant Physiol. 81, 75-80.

Tischler, C.R. and P.W. Voigt. 1987. Seedling morphology and anatomy of rangeland plant

species. In: Proc. Symp. Seed and Seedbed Ecology of Rangeland Plants, Tucson, AZ, pp. 5-13.

Tischler, C.R., and P.W. Voigt. 1993. Characterization of crown node elevation in Panicoid

grasses. J. Range Manage. 46, 436-439.

Tischler, C.R. and P.W. Voigt. 1995. Modifying seedling photomorphogenesis in kleingrass by

recurrent selection. Crop Sci. 35, 1613-1617.

Tischler, C.R., P.W. Voigt and R.L. Monk. 1997. Characterization of subcoleoptile internode

elongation in grasses grown in low light. J. Plant Physiol. 151, 465-470.

Vanderhoef, L.N. and W.R. Briggs. 1978. Red light-inhibited mesocotyl elongation in maize

seedlings. II. Kinetic and spectral studies. Plant Physiol. 63, 534-537.

Van Overbeek, J. 1936. Growth hormone and mesocotyl growth. Rec. Trav. Bot. Neerl. 33, 333-

340.

Young, B.A. and C.R. Tischler. 1994. Recurrent selection for greater shoot mass modifies seed

mass and seedling vigor in kleingrass. Seed Sci. Technol. 22, 467-475.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

327

Restoration of an Indigenous Serpentine Grassland and Oak Savanna

Ecosystem in Maryland

R. Wayne Tyndall1

Abstract

Serpentine soils are derived from serpentinite, a hydrated ultramafic rock. In eastern North

America, serpentinite is distributed in a discontinuous band from Newfoundland, Canada to

Alabama, USA. In the eastern USA, more than 90% of extant, native serpentine vegetation

occurs in Maryland and Pennsylvania. Serpentine vegetation in Maryland and Pennsylvania

evolved under conditions of severe nutrient stress, summer drought, and frequent and

widespread AmerIndian fires. These ecological factors contributed to the maintenance of

expansive C4 grassland and savanna communities until AmerIndian extirpation circa 1730. The

term “barrens” was used by settlers in the late 1600s and early 1700s to refer to the lack or

paucity of timber-size trees on the serpentine outcrops. Between 1750 and the early 1900s,

livestock grazing and selective clearing of woody plants inhibited afforestation of many outcrops,

while ungrazed barrens became forested. Today, very little grassland and oak savanna remain in

Maryland and Pennsylvania, and the term barrens is sometimes confusingly used to refer to

openings that have not yet become forested. On the largest serpentine outcrop in the eastern

United States, Soldiers Delight (700-800 acres), more than half of the indigenous vegetation has

been invaded by Virginia pine [Pinus virginiana Mill.] and greenbriar [Smilax sp.] since the

removal of livestock by the 1930s. Once the rapid rate of conifer expansion was recognized, a

research program was initiated in 1989 to examine the response of indigenous vegetation to

conifer clearing-and-prescribed burning as well as to clearing only. This paper will focus on the

results of this ongoing research and its incorporation into an ecosystem restoration strategy.

 

1

 Biodiversity Program, Maryland Department of Natural Resources, PO Box 68, Wye Mills, MD

21636
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

328

Vegetated Erosion Control Mats for Site Stabilization

Martin van der Grinten and Linda L. Gregory1

Introduction

Erosion control mats have been utilized effectively for stabilizing erosion-prone slopes allowing

the seed mix to become established. Over time, the mats biodegrade, and the established

vegetation stabilizes the soil from erosion.

The technique has some limitations on sites where the disturbance is created by high-energy

water flows or from concentrated foot traffic. At Acadia National Park, one of the most heavily

visited Parks, the problem exists in stabilizing and vegetating drainage ditches that experience

high water flows from concentrated rainstorms. Erosion control mats have been utilized to

stabilize the soil, but the seeded erosion control mix may fail to establish. This is due to a

combination of the flowing water washing seed from the site, late seeding dates, and

environmental limitations of the site.

To overcome these factors, a technique was proposed to grow the erosion control vegetation

directly into the erosion control mat in a nursery setting. Once the vegetation is established, this

erosion control mat sod would be transported to the site, rolled out and tacked down with pins.

The site would benefit with immediate erosion control provided by the mat and with the vegetation

immediately being able to continue growing and send down roots, thereby stabilizing the site. We

saw a potential use by Acadia National Park to help stabilize the critical area sites.

Preliminary Study

The types of erosion control mats available on the commercial market were reviewed to

determine their merits. An initial test was conducted at the USDA, Natural Resources

Conservation Service, Big Flats Plant Materials Center (PMC), using two types of matting that

had promise, including: (1) Bon Terra’s Bogmat (100% bio-degradable coir fiber mat 2 inch thick)

and (2) Bon Terra HP90 (100% bio-degradable coir fiber mat 1⁄2 inch thick). A plastic fiber mat of

1⁄2 inch thickness could have been used, but we preferred to use a biodegradable mat in the

national park.

At the PMC, seeds of grasses and forbs were sown onto both the Bog Mat and HP90 mat. The

mats were spread out over black plastic on greenhouse benches and then various depths of

greenhouse potting media (Metro-Mix 360) were spread over the mats. Seeds were spread, and

a light covering of potting media applied. The best results were obtained with the HP90 ( 1⁄2 inch

thick coir fiber mat) utilizing approximately 1⁄2 inch potting soil over the mat then seeded with red

fescue [Festuca rubra L]. The two inch thick mat did not perform well in the methods we followed.

The growing media tended to settle/subside into the fibrous mat after being watered, so a

vibration technique had to be refined during applications. Various grasses and forbs were tested

with limited success.

The HP90 with red fescue provided a solid, well rolled “carpet” in a few months. In late summer,

three-foot sections of the vegetated mats were placed in drainage ditches along the Carriage

Road near Eagle Lake, in Acadia National Park. We wanted to be sure the grass roots would

grow into the soil and hold the mats in place, especially under high water flows. Monitoring

continued for a year with the mats successfully surviving the winters and anchoring to the soil to

withstand the spring and summer run-off waters. With this success, it was decided to test this

technique on a larger scale at various sites in the park.

 

1

 USDA, Natural Resources Conservation Service, Big Flats Plant Materials Center, 3266-A State

Route 352, Corning, NY 14830 and USDI, National Park Service, Acadia National Park, P.O. Box

177, Bar Harbor, ME 04609
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

329

Field Trials

Growing the vegetated mats in a nursery setting was relatively simple. To facilitate the ease in

handling the potting media, a frame 4 feet wide and 66 feet long, was constructed of 1⁄2 inch x 4

inch lumber. Weed barrier mat was placed inside the frame, and the erosion control mat (4 ft x

66 ft) then rolled out. Greenhouse potting media was spread over the mat to a one-inch

thickness (after being watered, the media settled to a 1⁄2 inch final thickness). A wood board, cut

to the proper depth that rests on the frame can be pulled along as the potting media was placed,

to create uniform depth. The grass seed was spread over the media. Red fescue was seeded at

18 lbs acre-1. A light covering of potting media was hand spread and watered. During the

summer months, the mats were kept moist and an application of 15-15-15 fertilizer applied. After

3 months, the mats had a solid stand of grass with an extensive root system into the coir fiber

mat.

In mid-September, we cut 10 ft lengths of the vegetated erosion control mats, rolled them up and

transported them to Acadia National Park. Seven sites were selected in the park that included

two drainage ditch sites along Carriage Road at Eagle Lake that have concentrated water flows:

two drainage ditch sites on Carriage Road at Bubble Pond, one site near spillway at Jordon Pond

which was shaded and can have high water flows in major storms, and two sites along the

footpath near Otter Point (near cliffs by the Atlantic Ocean).

The park personnel placed of the vegetated erosion control mats. First, a two inch layer of topsoil

was spread on all the sites except at Jordan Pond. Then the 10-foot rolls of vegetated erosion

control mats were rolled out and tacked down using standard steel pins. When placing two mats

together, they were overlapped as you would shingles on a roof. The upper ends of the mats

were tacked securely to prevent any under-cutting from the flowing waters.

The installation at all seven sites went quickly and easily. It should be noted that the weight of

the 10 foot lengths was the limit for two people to handle without mechanical equipment. The

extensive root system of the grass held everything together to maintain the physical structure of

the growing media on the mats, and the mats held up well during the transport.

Results

The sites have been maintained for two years during which time there have been both occasions

for high water flows and periods of drought. At all sites, the vegetation has survived with the

roots growing well into the soil. In the high flow drainage ditches along the Carriage Road at

Eagle Lake, one of the mats started to tear loose at upper edge losing some of the vegetation.

The mats placed along the path at Otter Cliffs have done well, withstanding foot traffic for two

summer seasons. At Jordon Pond, the mats have remained in place with concentrated flows of

water in the spillway area.

Conclusion

The technique of growing vegetation on erosion control mats in a nursery setting and then

installing them on highly erodible sites is a viable erosion control revegetation system. For less

than $2.00 per linear foot for a four-foot wide coir fiber mat, a vegetated mat can be produced that

will effectively stabilize the soil and provide instant erosion control. This system was utilized in

Acadia National Park in a number of situations including stabilizing water drainages and steep

slopes and for revegetating critical areas and hiking trails. The installation of the mats was done

by park personnel with immediate visual and site stabilization benefits. Further studies are

needed to determine how forbs can be incorporated successfully into the seed mixes.

This system can be utilized at any site where establishing permanent vegetation is difficult due to

adverse human or environmental factors. The vegetated erosion control mat system is a simple

method that can be used to provide immediate site stabilization. Trade names are used solely to

provide specific information and should not be considered a recommendation or endorsement by

the USDA-NRCS or the USDI-NPS.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

330

Native Plants for National Parks

Martin van der Grinten, Judy Hazen Connery, Linda L. Gregory and John Dickerson1

Ensuring the integrity of vegetative ecosystems within National Parks is an increasing concern for

the National Park Service. In recent years, the use of native plant materials for revegetation

projects in Parks has received increased interest. Construction, maintenance, and visitor use

activities have resulted in the disturbance of soil and vegetation. To maintain natural conditions

in Parks, resource managers face the challenges of controlling erosion by blending revegetated

areas with the existing landscape while maintaining genetic integrity of the flora and preventing

the introduction of exotic species.

The National Park Service is also concerned with the preservation of threatened or endangered

species and with using locally native plant materials to perpetuate or recreate period plantings at

historic sites.

The USDA-Natural Resources Conservation Service (NRCS) Plant Materials Program (PMP) and

the USDI-National Park Service (NPS) developed a cooperative agreement to share technical

expertise and develop native plants for use in Park revegetation programs.

Through this agreement, the NRCS-PMP can be used to propagate ecotypes of native grasses,

wildflowers, shrubs and trees for individual National Parks and historic sites.

The NRCS maintains 26 Plant Material Centers (PMC) throughout the United States including

Alaska and Hawaii. These centers have been developing plant materials for conservation

programs since the 1930’s. Each center is located to take advantage of the characteristics of

soil, climate and topography common to certain parts of the country. The NRCS program has

screened a large number of species and has developed technologies used in revegetation work.

Each center has the seed cleaning and plant propagating facilities to handle a wide variety of

different species and produce seeds and transplants to high quality standards.

At the beginning of a project under the cooperative agreement, the PMC staff works with NPS

Park resource specialists at an individual Park to identify their needs. These include a list of plant

species, amount of plant materials requested, and projected planting dates. Seeds or plants are

then collected in the Park and sent to a nearby plant materials center. At the center, the seeds or

plants are reproduced, ensuring that the original genetic characteristics are preserved by isolating

the seed production fields. When the Park is preparing to initiate their revegetation work, the

seed and transplants are shipped to them to re-establish the native plant communities. Staffs

from both the Park and the PMC work together to ensure good survival through proper methods

of planting and seeding and placarding with signs to prevent trampling of plants by Park visitors.

The NRCS, Big Flats Plant Materials Center is currently cooperating with Acadia National Park in

Maine. Species are propagated to revegetate areas disturbed during roadway and facilities

construction in the Park. This work at Acadia National Park involves over 25 species of grasses,

forbs, shrubs, and trees. The activities have focused on seed and plant collections in the Park,

establishing seed increase fields and propagating plants, seed processing and conditioning ,and

delivering plant materials back to the Park. Numerous sites and roadway shoulders have been

revegetated by these seeds and plants with excellent survival. The good cooperation and

coordination of the Park’s resources management staff and the maintenance staff have ensured

proper planting and maintenance of the revegetated sites. Through their efforts, the Park has

met the challenges of controlling erosion and stabilizing sites with native plants, blending

revegetated sites with existing landscapes, and maintaining the genetic integrity of the plant

ecosystems.

 

1

 USDA, Natural Resources Conservation Service, Big Flats Plant Materials Center, 3266-A State

Route 352, Corning, NY 14830 and USDI, National Park Service, P.O. Box 177, Bar Harbor, ME

04609
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

331

Converting Tall Fescue Grasslands to Native Warm-Season Grasses

Brian E. Washburn and Thomas G. Barnes1

Tall fescue [Festuca arundinacea Schreb.] has been planted for hay, pasture, turfgrass, surface

mining reclamation, and revegetation of Conservation Reserve Program (CRP) lands on more

than 14 million hectares in the United States (Burns and Chamblee 1979; Ball et al. 1993). Over

90% of this tall fescue is infected with a fungal endophyte [Neotyphodium coenophialum (MorganJones & Gams) Glenn, Bacon & Hanlin] that forms a symbiotic relationship with tall fescue

(Bacon and Siegel 1988), making the tall fescue more competitive, increasing its ability to survive,

and making it very difficult to kill. Tall fescue has been shown to affect the nutritional ecology of

songbirds and Canada geese (Conover and Messmer 1996a; Conover and Messmer 1996b) and

these grasslands do not provide quality habitat for northern bobwhite quail and cottontail rabbits

because they form dense monocultures with low botanical diversity, lack sufficient bare ground,

and have poor vertical structure (Barnes et al. 1995).

Habitat manipulation and disturbance improves tall fescue-dominated grasslands by converting

these fields into habitat more suitable for wildlife (Washburn et al. 2000). A preliminary

disturbance study evaluated prescribed burning, herbicide application, and disking. The results

showed the most effective treatment for eliminating tall fescue was a spring glyphosate (product

name Round-UpTM) application (Madison et al. 1995). Unfortunately, tall fescue is difficult to kill

(Defelice and Henning 1990), and habitat disturbances (e.g. burning, herbicide application, or

disking) provide short-term tall fescue control (Madison et al. 1995). Killing the tall fescue sod

and seeding native grass mixtures is a more effective, long-term solution (Washburn et al. 2000)

and provides better wildlife habitat, quality hay, and summer forage for domestic livestock.

In the past, native warm-season grasses (NWSG) have developed a reputation for being difficult

to establish because they require special seeding equipment, took three to five years to become

fully established, and the seed was expensive. Recent advances in herbicide technology,

increased availability of NWSG seed, and increased access to seeding equipment capable of

planting NWSG has increased the amount of NWSG seeded. More importantly, NWSG can now

be successfully established in one growing season (Washburn et al. 1999).

During the past three years our research program has focused on determining effective methods

of killing tall fescue with herbicides and replacing fescue sod with NWSGs. This paper

summarizes the results of these experiments and will challenge many of the preconceived ideas

about the difficulty of killing tall fescue and establishing NWSG. We also want to provide

recommendations to managers who desire to establish NWSG.

Methods

All experiments were conducted in tall fescue-dominated fields located in several Kentucky

physiographic regions. Study plots were established in a range of soil types, drainage types, and

fertility levels. Soils on the various study sites included loams, silt loams, silty clay loams, and

flaggy silty clays (Washburn et al. 1999, Washburn and Barnes 2000a, Washburn and Barnes

2000b, Washburn et al. 2000). Soils ranged from shallow to very deep, had slow to moderately

rapid permeability, were somewhat poorly drained to well-drained, and were low to moderately

high in natural fertility. Sites ranged from flat (0-2% grade) to steeply sloping (15-20% grade).

The fields were primarily tall fescue monocultures (Barnes et al. 1995) with a few other plant

species such as goldenrods [Solidago spp.], horse nettle [Solanum carolinense L.], and purpletop grass [Tridens flavus (L.) Hitchc.] were also present.

 

1

 Department of Forestry, University of Kentucky, T.P. Cooper Bldg., Lexington, KY 40546-0073
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

332

Several studies were designed to evaluate the efficacy of single spring or fall herbicide

applications or a combination of imazapic (product name PlateauTM) plus glyphosate (product

name Round-Up PROTM) tank mixtures. These were applied during four different tall fescue

growth stages (spring vegetative growth stage, boot stage, summer dormancy stage, and fall

vegetative growth stage) and evaluated two months after treatment and the following growing

season (Table 1).

Table 1. Herbicides and herbicide mixtures evaluated for efficacy in killing tall fescue in field

experiments conducted during 1996-1998 in Kentucky.

Herbicide(s) Rate

(oz. acre-1)

 Rate

(kg ai ha-1)

Application Timing

Glyphosate 64 2.24 Spring Growth or Fall

Growth Stage

Imazapic1 12 0.21 Spring Growth,

Boot Stage,

Summer Dormancy, or

Fall Growth Stage

Imazapic1 plus

 glyphosate

12 +

16

0.21+

0.56

Spring Growth,

Boot Stage,

Summer Dormancy, or

Fall Growth Stage

Imazapic1 plus

 glyphosate

12 +

32

0.21+

1.12

Spring Growth,

Boot Stage,

Summer Dormancy, or

Fall Growth Stage

1

 Surfactant (Sun-It IITM) at 1 quart acre-1 and 28-0-0 liquid fertilizer at 1 quart acre-1 were included

with all imazapic applications.

Three field experiments were completed to meet the objective of establishing NWSG in fescue

sod during the spring or fall (Table 2). Fields were burned in March prior to herbicide applications

to remove residual standing crop biomass. Herbicides were applied in April using an ATVmounted sprayer equipped with flat fan nozzles. NWSG were seeded in May/June using a

TruaxTM or TyeTM no-till drill. Indiangrass [Sorghastrum nutans (L.) Nash], big bluestem

[Andropogon gerardii Vitman], and little bluestem [Schizachyrium scoparium (Michx.) Nash] were

planted in pure stands or as part of a NWSG mixture at a rate of 6 lbs. PLS acre-1, a rate

recommended for wildlife plantings (Capel 1995). Post-emergence imazapic applications (Table

2) were applied when post-planting vegetation reached 10-12 inches in height during the initial

growing season (July - September) to some treatment combinations. Tall fescue control, NWSG

establishment, and resulting habitat characteristics for wildlife were evaluated by estimating plant

species coverage in ten 1-m2

 herbaceous sampling plots in each treatment plot during the first

two or three growing seasons following treatment application (Bonham 1989).

A further experiment was conducted to evaluate current CRP label rates. We evaluated

treatments that utilized 4 oz. acre-1 of imazapic applied pre-emergence, a tank mixture of

glyphosate and imazapic (4 oz. acre-1), or applying a glyphosate application followed by 4 oz.

acre-1 of imazapic applied at the time of planting (Table 2). Because imazapic is relatively

expensive and high rates are best for killing fescue (Washburn et al. 1999), we designed an

experiment to evaluate using imazapic plus 2,4-D Amine for controlling weeds using conventional

tillage prior to seeding. Study areas were deep-moldboard plowed, disked, and cultipacked to kill

the tall fescue sod and prepare a firm seedbed. NWSG (Indiangrass, big bluestem, and little

bluestem) and four native forbs (purple coneflower [Echinacea purpurea (L.) Moench], lance-
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

333

leaved coreopsis [Coreopsis lanceolata L.], Illinois bundleflower [Desmanthus illinoensis (Michx.)

MacMill. ex B. L. Rob. & Fernald], and purple prairie clover [Dalea purpurea Vent.] were

handseeded in pure stands at 6 lbs. PLS acre-1, followed by cultipacking. Herbicides (4-12 oz.

acre-1 of imazapic alone and in combination with an equal amount of 2,4-D Amine) were applied

pre-emergence (at planting) or post-emergence (at the 4-6 leaf stage) to evaluate their efficacy

for weed control and assistance in NWSG establishment. Density (number of seedlings m-2) of

native grass and forb plants was determined during the initial two growing seasons.

Table 2. Treatments tested for efficacy of converting tall fescue to native warm-season grasses

during three experiments conducted in Kentucky from 1996 - 1999.

Prescribed

burn

Pre-emergence

herbicide

Time of

Planting

Post-emergence

herbicide

None Glyphosate1 Spring None

Spring Glyphosate1 Spring None

Spring Glyphosate1 Spring 8 oz. Imazapic2

Spring Glyphosate1 Spring 12 oz.Imazapic2

None Glyphosate1 Fall None

Fall3 Glyphosate1 Fall None

Fall3 Glyphosate1 Fall 8 oz. Imazapic2

Fall3 Glyphosate1 Fall 12 oz. Imazapic2

Spring 4 oz. Imazapic4 Spring None

Spring 8 oz. Imazapic4 Spring None

Spring 12 oz. Imazapic4 Spring None

Spring 12 oz. Imazapic4 Spring 8 oz. Imazapic2

Spring 12 oz. Imazapic4 Spring 12 oz. Imazapic2

Fall3 12 oz. Imazapic4 Fall None

Fall3 12 oz. Imazapic4 Fall 8 oz. Imazapic2

Fall3 12 oz. Imazapic4 Fall 12 oz. Imazapic2

Spring Glyphosate plus

4 oz. Imazapic4 Spring None

Spring Glyphosate Spring 4 oz. Imazapic4

(At planting)5

1

 Glyphosate was applied at a rate of 2 quarts acre-1. 2

 Post-emergence herbicides were applied during the initial growing season.

3

 Pre-emergence herbicides were applied prior to prescribed burns.

4

 Surfactant (Methylated Soybean Oil) at 1 quart acre-1 and 28-0-0 liquid

 fertilizer at 1 quart acre-1 were included with the imazapic application. 5

 The imazapic was applied the same day as the seed was planted

The tolerance of many native forbs and legumes to various rates of imazapic is currently

unknown. Determining the tolerance of native species to imazapic may increase the number of

native wildflowers appropriate for inclusion in NWSG mixtures. We implemented a greenhouse

study to examine the effects of pre-emergence imazapic applications on the germination and

growth of seedlings of 2 native grasses, 3 native legumes, and 11 native forbs. Imazapic was

applied pre-emergence at a rate of 0, 1, 2, and 4 oz. acre-1 to soil containing seed from each

species. The total number of seedlings for each plant species was determined for each imazapic

level and compared using chi-squared analyses.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

334

The addition of fertilizer to first-year plantings may aid in the establishment of NWSGs. During

1998, we conducted an experiment to determine if NWSG coverage and plant height were

increased by the addition of fertilizer during the initial growing season. The study area was

burned in March, an herbicide tank mixture (imazapic @ 12 oz. acre-1 plus glyphosate @ 2 quarts

acre-1) was applied during April, and a NWSG mixture was no-till seeded @ 6 lbs. PLS acre-1

during early May. Four fertilizer treatments (Control, Water only, 25 lbs. 10-10-10 acre-1, and 50

lbs. 10-10-10 acre-1) were applied using a handsprayer six weeks after seeding. Eight weeks

after fertilizer application, NWSG cover (%), NWSG seedling density (number ft-2), and seedlings

height (inches) were determined in each treatment.

In addition to examining pre-emergence use of imazapic for weed control, we also wanted to

explore how imazapic could be used to "release" NWSG stands that were "struggling" from weed

competition. The NWSG stands we examined were previously planted (2 or more years old) or

were naturally occurring NWSG on Kentucky barrens. We applied imazapic at 12 oz. acre-1 postemergence to 6 glyphosate treatments at 3 study sites during April of 1998. The glyphosate

treatments had less than 30% NWSG cover prior to the imazapic application. NWSG cover (%)

was determined at the end of the 1998-growing season. Also, we determined the effectiveness of

prescribed burning and imazapic applications for tall fescue control and increasing NWSG

coverage in native barrens. We designed an experiment and implemented combinations of

prescribed burning and post-emergence applications of imazapic (4-12 oz. acre-1), with and

without non-ionic surfactant (Aquagene 90TM) during 1999 at the Raymond Athey Barrens in

Kentucky. Tall fescue cover (%) and NWSG cover (%) were determined in each treatment plot

during the fall of 1999.

Results and Discussion

Tall Fescue Control -- Glyphosate and imazapic can be used to kill existing tall fescue sod. The

best treatment to control tall fescue is a spring prescribed burn followed by a single application of

glyphosate at 2 quarts acre-1 (2.24 kg active ingredient (ai) ha-1) or imazapic at 12 oz. acre-1 (0.21

kg ai ha-1) in April or May (Table 3; Washburn et al. 1999, Washburn et al. 2000). Imazapic

applications should include surfactant (i.e. methylated soybean oil) at 1 quart acre-1 and 28-0-0

liquid fertilizer at 1 qt acre-1. These two treatment combinations effectively reduced or eliminated

tall fescue at all study sites (Washburn et al. 1999, B. E. Washburn, University of Kentucky,

unpubl. data). The prescribed burn removes the heavy litter layer and stimulates tall fescue

growth, thus increasing herbicide efficacy and plant-herbicide contact. Herbicides should be

applied when the tall fescue reaches a height of 6-8 inches.

Although spring herbicide applications appeared to be the most effective, our research examining

the effects of application timing on tall fescue control demonstrated that imazapic will effectively

kill tall fescue at any physiological stage (Washburn and Barnes 2000a). Imazapic was more

effective than glyphosate for totally eliminating tall fescue from treatment plots throughout our

experiments. Imazapic has a 40-45 day soil half-life and plant uptake of imazapic occurs both

through the leaf surfaces and the roots (Shaner and O’Conner 1991). Glyphosate is a foliaracting herbicide with no residual effect (Grossbard and Atkinson 1985). The additional plant

uptake via the soil-root pathway may account for the greater efficacy of imazapic in eradicating

fescue.

NWSG Establishment -- Our results indicate that a spring prescribed burn followed by a preemergence imazapic application at 12 oz. acre-1 (0.21 kg ai ha-1) and no-till seeding NWSG is the

most effective method for establishing NWSG directly into tall fescue sod (Table 4; Washburn et

al. 2000). Moreover, this treatment combination resulted in established stands of NWSG during

the first growing season at most study sites (Washburn et al. 1999, B. E. Washburn, University of

Kentucky, unpubl. data). In addition to providing tall fescue control, applying imazapic preemergence provides weed control and reduces plant competition during the initial growing

season, allowing planted NWSG seed to germinate and establish.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

335

Table 3. Percent tall fescue remaining at 2-3 months post-treatment of imazapic and imazapic

plus glyphosate tank mixtures.1

Season of Application

Imazapic

12 oz. acre-1

Imazapic

12 oz. acre-1 +

Glyphosate

1 pint acre-1

Imazapic

12 oz. acre-1 +

Glyphosate

1 quart acre-1

Spring Vegetative

Growth

0.82 0.5 0.1

Boot Stage 0.8 0.4 0.6

Summer Dormancy 0.7 0.3 0.1

Fall Vegetative Growth 1.1 0.1 0.1

1

 Data from Washburn and Barnes (2000a).

2

 No difference (p<0.05) among means using Fisher’s protected LSD test.

Spring treatments that included a pre-emergence glyphosate application were less successful in

establishing NWSG. High amounts of annual and perennial weeds were present (due to a lack of

weed control) and apparently resulted in severe competition (Bragg and Sutherland 1989,

Schramm 1990) and deterred NWSG establishment. Similarly, high levels of residual tall fescue

and a lack of weed control from pre-emergence herbicides applied in the fall (prior to the growing

season) resulted in severe weed interference and deterred NWSG establishment in the fall

treatments. Fall seedings generally failed which has been previously reported (Gaynor and

Meyer 1999).

Table 4. Percent NWSG in no-till treatments cover after one or two growing seasons at 10 study

sites in Kentucky during 1997-1998.1

Treatment Year 1 Year 2

-------------- NWSG (%) -----------

Spring Burn - Glyphosate - Seed NWSG 0.4 11

Spring Burn - Imazapic - Seed NWSG 27 60

Spring Burn - Glyphosate - Seed NWSG - 8 oz./ac

POST Imazapic

-----2 18

Spring Burn - Glyphosate - Seed NWSG -

12 oz./ac POST Imazapic

----- 19

Spring Burn - imazapic - Seed NWSG -

8 oz./ac POST Imazapic

----- 53

Spring Burn - Imazapic - Seed NWSG12 oz./ac POST Imazapic----- 63

1

 Data from Washburn et al. (1999) and Washburn et al. (2000).

2

 Not evaluated because POST Imazapic was applied at the end of year 1.

We recommend a spring burn followed by a pre-emergence application of imazapic at 12 oz.

acre-1 and no-till seeding to establish Indiangrass, big bluestem, and little bluestem, both in pure

stands and in mixtures. A seeding rate of 6 lbs. PLS acre-1 is appropriate for establishing NWSG

for wildlife habitat. However, seeding high rates (8-12 lbs. PLS acre-1) would be more appropriate

for NWSG stands being established for hay forage and/or livestock grazing. Switchgrass,

sideoats grama [Bouteloua curtipendula (Michx.) Torrey], and Eastern gamagrass [Tripsacum
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

336

dactyloides (L.) L.] are intolerant to this level of imazapic and this treatment is not recommended

for establishing these species (Vollmer 1998).

Table 5. NWSG seedling density (no. m-2) in treatments for CRP lands at the end of the first

growing season at 3 study sites in Kentucky during 1999.

Treatment TLWMA YWMA Hardin Co.

no. m-2 % Cover no. m-2 % Cover no. m-2 % Cover

Big Bluestem

Imazapic 4 oz. 4.3 9 1.1 1 1.1 1

Glyphosate +

Imazapic 4 oz.

6.5 15 0 9 2.2 4

Glyphosate + 4

oz. Imazapic At

Planting

43.0 79 7.5 10 5.4 9

Indiangrass

Imazapic 4 oz. 1.1 1 0 1 0 0

Glyphosate +

Imazapic 4 oz.

16.1 18 1.1 3 1.1 1

Glyphosate + 4

oz. Imazapic At

Planting

23.7 46 9.7 16 5.4 4

Little Bluestem

Imazapic 4 oz. 2.2 4 0 2 0 0

Glyphosate +

Imazapic 4 oz.

9.7 20 0 4 0 1

Glyphosate + 4

oz. Imazapic At

Planting

10.8 21 9.7 11 4.3 4

For NWSG establishment on CRP lands, our research indicates that spring burning followed by a

pre-emergence application of glyphosate at 2 quarts acre-1 (2.24 kg ai ha-1), no-till seeding, and

applying imazapic at 4 oz. acre-1 (0.07 kg ai ha-1) at the time of planting is a very effective

treatment (B. E. Washburn, University of Kentucky, unpubl. data). This treatment combination

allows the glyphosate to kill the tall fescue and the imazapic to provide weed control for

germinating and establishing NWSG plants (Table 5). In contrast, the treatments utilizing

imazapic at 4 oz. acre-1 or a glyphosate and imazapic tank mixture provided tall fescue control but

did not provide sufficient weed control to allow NWSG establishment. Conventional tillage

provides an alternative method of tall fescue conversion and NWSG establishment on acreage

not susceptible to severe erosion problems. Indiangrass, big bluestem, and little bluestem were

successfully established in one growing season using conventional tillage, handseeding or drilling

NWSG seed, and applying imazapic to provide weed control (Table 6; Washburn and Barnes

2000b). We recommend applying a pre-emergence application of imazapic at 4 oz. acre-1 (0.07

kg ai ha-1) at the time of planting.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

337

Table 6. Grass seedling density (number m-2) 8 weeks after planting and pre-emergence

herbicide applications.

Treatment Big Bluestem Indiangrass Little Bluestem

Control 7.0*1 7.2* 4.1*

Imazapic 4 oz. 20.4 19.1 16.8

Imazapic 8 oz. 14.7 20.7 13.9

Imazapic 12 oz. 16.4 14.4 17.7

Imazapic 4 oz. + 2,4-

D 4 oz.

12.8 16.1 16.0

Imazapic 8 oz. + 2,4-

D 8 oz.

13.3 14.6 16.9

Imazapic 12 oz. +

2,4-D 12 oz.

11.2 12.1 18.6

1

 Control was different (p<0.05) from herbicided treatments using Fisher’s protected LSD test.

Forbs -- Many native forbs are intolerant to high rates of imazapic (Vollmer 1998). Although the

tolerance of many species is unknown, our research indicates blackeyed susans [Rudbeckia hirta

L.], lance-leaved coreopsis, partridge pea [Chamaecrista fasciculata (Michx.) Greene], Illinois

bundleflower, purple prairie clover, and ironweed [Vernonia gigantea (Walter) Trel. ex Branner &

Coville] are tolerant to imazapic at 12 oz. acre-1 and are appropriate for inclusion in NWSG

mixtures. If plant species intolerant to imazapic are desired, we recommend interseeding those

species into the establishing NWSG stand during the second growing season.

Two legumes and 7 forbs were tolerant of a pre-emergence application of imazapic at 4 oz. acre-1

(Table 7). Although the pre-emergence application of imazapic did not reduce the number of

seedlings (germination rate), the growth and development of plant seedlings in the treatments

that received the higher rates of imazapic were slower compared to the controls. The number of

seedlings in the treatment cells receiving imazapic at 2 or 4 oz. acre-1 was significantly lower for

the 2 grasses, 1 legume, and 4 forbs. The 4 oz. acre-1 imazapic application reduced the number

of emerging seedlings by 25-60% compared to the controls (Table 7).

Consequently, our results suggest the 9 species tolerant to 4 oz. acre-1 of imazapic may be

appropriate for inclusion in NWSG mixtures being established with imazapic, whereas those

exhibiting no or very little tolerance to imazapic may be species to avoid. However, more field

testing and greenhouse studies are needed to determine which other forb and legume species

may also be appropriate for inclusion in NWSG mixtures being established using imazapic.

Fertilizer -- The application of fertilizer to an establishing NWSG stand during the initial growing

season did not increase NWSG seedlings density or NWSG cover compared to non-fertilized

treatments (Table 8). However, the application of fertilizer did increase the average height of

planted NWSG seedlings. Our results suggest the application of 25 lbs. of 10-10-10 fertilizer per

acre when planted NWSG seedlings are 6-8 inches tall can increase the size of establishing

NWSG plants and may increase their chance of survival through the first winter.

We recommend the application of fertilizer only when sufficient weed control is provided by preemergence herbicides and no weeds are present. The application of fertilizer to mixed stands of

NWSGs and weeds provides much more benefit to the weeds and will result in high amounts of

weed coverage and increased competition for the NWSG seedlings.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

338

Table 7. Tolerance of selected grasses, legumes, and forbs to imazapic (0-4 oz. acre-1) and

percent reduction in seedling number by 4 oz. acre-1 imazapic during a greenhouse study

conducted at the University of Kentucky.

Species Maximum

Ratea

(oz. acre-1)

Percent

Reduction

by 4-oz.

acre-1

Grasses

 Prairie cordgrass [Spartina pectinata Link] 11 45

 Junegrass [Koeleria macrantha (Ledeb.)

Schult.]

01 35

Legumes

 Roundheaded bushclover [Lespedeza

 capitata Michx.]

4 0

 Leadplant [Amorpha canescens Pursh] 4 0

 Showy Tick Trefoil [Desmodium canadense

 (L.) DC.]

11 40

Forbs

 Butterfly milkweed [Asclepias tuberosa L.] 4 0

 Rough blazingstar [Liatris aspera Michx.] 4 0

 Purple coneflower [Echinacea purpurea (L.)

Moench]

4 0

 New England aster [Aster novae-angliae L.] 4 0

 Heath aster [Aster ericoides L.] 11 50

 Smooth aster [Aster laevis L.] 11 35

 Sky Blue aster [Aster oolentangiensis Riddell] 4 0

 Canada goldenrod [Solidago canadensis L.] 11 25

 Sweet black-eyed susan [Rudbeckia

 subtomentosa Pursh]

4 0

 Brown-eyed susan [Rudbeckia triloba L.] 4 0

 Wild Bergamot [Monarda fistulosa L.] 01 60

1

 Exceeding the maximum rate significantly (p<0.05) reduced the number of germinating

seedlings.

Enhancing NWSG Stands -- Our results indicate applying post-emergence imazapic (12 oz ac-1)

to "struggling" NWSG during the second or third growing season is highly effective for controlling

reinvading tall fescue and enhancing NWSG (Washburn et al. 1999). The number of NWSG

plants and percent cover of NWSG increased after imazapic was applied (Table 9). The postemergence imazapic application apparently decreased competition from annual and perennial

weeds, resulting in increased growth of NWSGs. Overall, plant species sensitive to imazapic,

such as tall fescue, hairy crabgrass [Digitaria sanguinalis (L.) Scop.] and johnsongrass [Sorghum

halepense (L.) Pers.], were removed by the post-emergence imazapic application. In contrast,

species tolerant to imazapic, such as NWSGs, broomsedge bluestem [Andropogon virginicus L.],

and Kentucky bluegrass [Poa pratensis L.], increased considerably due to decreased competition

from the removal of dominant "weedy" species.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

339

Table 8. Seedling density, seedling height, and NWSG cover (%) six weeks after application of

fertilizer treatments during a field experiment in Kentucky during 1998.

Treatment

Seedling density

(number ft-2)

NWSG Cover

(%)

Seedling Height

(inches)

Control 6.3 60.4 14.4*

Water Only 3.7*1 46.8* 15.3*

25 lbs. 5.5 62.5 26.9

50 lbs. 6.3 75.8 30.0

1

 Differences (p<0.05) among means using Fisher’s protected LSD test.

Table 9. Percent NWSG cover in fall 1998 following a post-emergence application of imazapic at

12 oz. acre-1 in April 1998.

Treatment Fayette Muhlenberg Caldwell

Spring Glyphosate 49*1 90* 100*

Spring Burn & Spring

Glyphosate

82* 100* 100*

Fall Burn & Spring

Glyphosate

24 94* 43

Fall Glyphosate 0 25 0

Fall Burn &

Fall Glyphosate

2 30 12

Spring Burn & Fall

Glyphosate

0 75* 27

1

 Differences (p<0.05) among means using Fisher’s protected LSD test.

Post-emergence herbicide applications may be useful for enhancing the quality of native tallgrass

prairie ecosystems in Kentucky and other states. Our results indicate that spring burning followed

by a post-emergence application of imazapic at 10 oz. acre-1 (0.175 kg ai ha-1) with nonionic

surfactant at 1 quart acre-1 is the most effective treatment for eradicating tall fescue and

increasing the coverage of existing NWSG (Table 10). Prescribed burning followed by an

imazapic application of 10 oz. acre-1, 4 oz. acre-1 + NIS, and 8 oz. acre-1 + NIS also reduced tall

fescue and increased NWSGs. Similarly, if the use of prescribed burning is not an option, we

recommend using a single post-emergence application of imazapic at 10 oz. acre-1 with nonionic

surfactant at 1 quart acre-1. Indiangrass, big bluestem, little bluestem, broomsedge bluestem,

and tall dropseed [Sporobolus compositus (Poir.) Merr.] are NWSG species that responded very

well to the imazapic applications in our studies. However, due to the fact that many forb species

are intolerant to imazapic or their tolerance is currently unknown, we recommend caution in using

imazapic if important, rare, or endangered native forbs are present.

Conclusions

Glyphosate and imazapic are effective tools for eradicating tall fescue. Spring prescribed burning

followed by an application of glyphosate at 2 quarts acre-1 or an application of imazapic at 12 oz.

acre-1, surfactant at 1 quart acre-1, and 28-0-0 fertilizer at 1 quart acre-1 provides effective tall

fescue control. Additionally, imazapic will kill tall fescue in any physiological stage.
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

340

Table 10. Tall fescue cover (%) and NWSG cover (%) at the end of the initial growing season

following burning and herbicide applications at Raymond Athey Barrens in Kentucky during 1999.

Treatment Tall fescue (%) NWSG cover (%)

Control 72.0*1 14.2*

Burn Only 41.4 15.4*

4 oz. Imazapic 44.4 29.2

8 oz. Imazapic 33.0 33.4

10 oz. Imazapic 22.6 36.4

4 oz. Imazapic + NIS2 25.6 35.6

8 oz. Imazapic + NIS2 40.4 23.2

10 oz. Imazapic + NIS2 8.2 52.4

Burn, 4 oz. Imazapic 13.8 36.2

Burn, 8 oz. Imazapic 13.2 49.8

Burn, 10 oz. Imazapic 4.5 39.8

Burn, 4 oz. Imazapic + NIS2 8.0 45.8

Burn, 8 oz. Imazapic + NIS2 8.5 42.4

Burn, 10 oz. Imazapic + NIS2 3.4 60.4

1

 Control was different (p<0.05) from herbicided treatments using Fisher’s protected LSD test. 2

 Non-ionic surfactant (Aquagene 90TM) was included at a rate of 1 quart acre-1.

Mixed and pure stands of Indiangrass, big bluestem, and little bluestem can be successfully

established in one growing season using both no-till and conventional tillage methods and a preemergence imazapic application. A rate of 12 oz. acre-1 is recommended for no-till situations.

This rate kills tall fescue sod and provides sufficient weed control for establishing NWSG

seedlings. Under current regulations, the best method for NWSG establishment on CRP acreage

is to apply glyphosate at 2 quarts acre-1 to kill the tall fescue and 4 oz. acre-1 of imazapic at

planting to provide weed control. Conventional tillage kills the tall fescue sod, and 4 oz. acre-1 of

imazapic applied at the time of seeding provides the necessary weed control for NWSG

establishment.

Imazapic is also effective in enhancing existing NWSG stands with a significant tall fescue

component. Prescribed burning followed by a post-emergence imazapic (10 oz. acre-1 plus

nonionic surfactant) application is an effective method for eradicating tall fescue and increasing

NWSG coverage in previously planted NWSG stands or degraded tallgrass prairie ecosystems.

References

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Ball, D.M., J.F. Pederson, and G.D. Lacefield. 1993. The tall fescue endophyte. American

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Barnes, T.G., L.A. Madison, J.D. Sole, and M.J. Lacki. 1995. An assessment of habitat quality for

northern bobwhite in tall fescue dominated fields. Wildlife Society Bulletin 23:231-237.
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Bonham, C.D. 1989. Measurements for terrestrial vegetation. John Wiley and Sons, Inc., New

York, NY. 338 p.

Bragg, T.B. and D.M. Sutherland. 1989. Establishing warm-season grasses and forbs using

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Burns, J.S. and D.S. Chamblee. 1979. Adaptation. p. 9-30 In R.C. Buckner and L.P. Bush,

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geese grazing endophyte-infected tall fescue. Condor 98:859-862.

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infected tall fescue (Festuca arundinacea) pastures with herbicides. Weed Science 38:628-633.

Gaylor, V.A. and M.H. Meyer. 1999. Effects of seeding date on establishment of prairie grasses in

Minnesota. Minnesota Department of Transportation MN/RC-1999-16. 38 p.

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Madison, L.A. 1994. Impacts of disturbance in tall fescue dominated fields on northern bobwhite

habitat. MS thesis, Department of Forestry, The University of Kentucky, Lexington, KY. 146 p.

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Association of Fish and Wildlife Agencies 49:525-536.

Schramm, P. 1990. Prairie restoration: a twenty-five year perspective on establishment and

management. In Proceedings of the Twelfth North American Prairie Conference, Cedar Falls,

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Shaner, D.L. and S.L. O’Conner. 1991. The imidazolinone herbicides. CRC Press, Inc., Boca

Raton, FL. 290 p.

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Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

342

Appendix A: Alphabetic List of Common Names of Plants. Common names are as used in this

Proceedings. Scientific names are in accordance with GRIN (Germplasm Resources Information

Network) the official ARS site for plant names. More information on GRIN can be found at:

http://www.ars-grin.gov/npgs/.

Common Name Scientific Name

Alfalfa Medicago sativa L.

Alsike clover Trifolium hybridum L.

American beachgrass Ammophila breviligulata Fernald

Annual ryegrass Lolium multiflorum Lam.

Arrowfeather Aristida purpurascens Poir.

Aster Aster furcatus E.S. Burgess

Autumn olive Elaeagnus umbellata Thunb.

Barnyard grass Echinochloa crus-galli (L.) P. Beauv.

Beach sunflower Helianthus debilis Nutt.

Beaked panicum Panicum anceps Michx.

Bermuda grass Cynodon dactylon (L.) Pers.

Blackberry Rubus sp.

Black medic Medicago lupulina L.

Blackeyed Susan Rudbeckia hirta L.

Big bluestem Andropogon gerardii Vitman

Birdsfoot trefoil Lotus corniculatus L.

Bitter panic grass Panicum amarum Elliott var. amarulum (Hitchc. & Chase) P.G.

Palmer

Bluebonnets Lupinus subcarnosus Hook.

Blue grama Bouteloua gracilis (Kunth) Lag. ex Griffiths

Blue maidencane Amphicarpum muhlenbergianum (Schult.) Hitchc.

Bush clover Lespedeza cuneata (Dum. Cours.) G. Don

Bottlebrush grass Elymus hystrix L.

Broomsedge bluestem Andropogon virginicus L.

Brown-eyed susan Rudbeckia triloba L.

Browncane plumegrass Saccharum brevibarbe (Michx.) Pers.

Bur marigold Bidens aristosa (Michx.) Britton

Bushy bluestem Andropogon glomeratus (Walter) Britton et al.

Butterfly milkweed Asclepias tuberosa L.

Canada bluejoint Calamagrostis canadensis (Michx.) P. Beauv.

Canada brome Bromus pubescens Muhl. ex Willd.

Canadian goldenrod Solidago canadensis L.

Canada wildrye Elymus canadensis L.

Cardinal Flower Lobelia cardinalis L.

Carolina jointtail grass Coelorachis cylindrica (Michx.) Nash

Carostan flaccidgrass Pennisetum flaccidum Griseb.

Cattail Typha latifolia L.

Caucasian bluestem Bothriochloa caucasica (Trin.) C.E. Hubb.

Chewing’s fescue Festuca rubra var. commutata Gaudin

Chalky bluestem Andropogon glomeratus (Walter) Britton et al.

var. glaucopsis

Clasping coneflower Dracopis amplexicaulis (Vahl) Cass.

Coastal bermuda grass Cynodon dactylon (L.) Pers.

Coastal little bluestem Schizachyrium scoparium

subsp. littoralis (Nash) Gandhi & Smeins

Coastal panic grass Panicum amarum Elliott

Coastal panic grass Panicum amarum var. amarulum (Hitchc. & Chase) P.G. Palmer

Corn Zea mays L.

Corn speedwell Veronica arvensis L.

Costus Costus allenii Maas
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

343

Cotton Gossypium hirsutum L.

Crabgrass Digitaria sanguinalis L. Scop.

Crinkled hairgrass Deschampsia flexuosa (L.) Trin.

Dandelion Taraxacum officinale Weber ex F. H. Wigg. group

Deertongue Dichanthelium clandestinum (L.) Gould

Delphinium Delphinium nelsonii Greene

Dogbane Apocynum cannabinum L.

Dropseed Sporobolus indicus var. flaccidus (Roem. & Schult.) Veldkamp

Drummondii phlox Phlox drummondii Hook.

Dwarf willow Salix x cottetii Jos. Kern

Eastern hemlock Tsuga canadensis (L.) Carriere

Eastern gamagrass Tripsacum dactyloides (L.) L.

English plantain Plantago lanceolata L.

Espeletia Espeletia schultzii Wedd.

Fall panicum Panicum dichotomiflorum Michx.

Field chickweed Cerastium arvense L.

Flat pea Lathyrus sylvestris L.

Florida paspalum Paspalum floridanum Michx.

Foxtail Setaria spp.

Setaria magna Griseb. Giant foxtail

Gamagrass Tripsacum andersonii J.R. Gray

Gamagrass Tripsacum dactyloides (L.) L. 

Gamagrass Tripsacum floridanum Porter ex Vasey

Gamagrass Tripsacum maizar Hern.-Xol. & Randolph

Gamagrass Tripsacum zopilotense Hern.-Xol. & Randolph

Gentianella Gentianella germanica (Willd.) Borner ex E.F. Warb

Giant foxtail Setaria faberi R. Herrm.

Giant foxtail Setaria magna Griseb.

Goldenrods Solidago spp.

Grape Vitis sp.

Grass-leaved golden aster Pityopsis graminifolia (Michx.) Nutt.

Greenbriar Smilax sp.

Green and yellow foxtails Setaria spp.

Hairy clover Lespedeza hirta (L.) Hornem.

Hairy crabgrass Digitaria sanguinalis (L.) Scop.

Hairy indigo Indigofera hirsuta L.

Hard fescue Festuca brevipila R. Tracey

Heath Aster Aster ericoides L.

Hog peanut Amphicarpaea bracteata (L.) Fernald

Horse nettle Solanum carolinense L.

Hypoxis Hypoxis decumbens L.

Illinois bundleflower Desmanthus illinoensis (Michx.) MacMill. ex B. L. Rob. & Fernald

Indiangrass Sorghastrum nutans (L.) Nash

Ipomopsis Ipomopsis aggregata (Pursh) V. E. Grant

Ironweed Vernonia gigantea (Walter) Trel. ex Branner & Coville

Japanese honeysuckle Lonicera japonica Thunb.

Jewel weed Impatiens capensis Meerb.

Johnsongrass Sorghum halepense (L.) Pers.

Junegrass Koeleria macrantha (Ledeb.) Schult.

Kentucky bluegrass Poa pratensis L.

Kleingrass Panicum coloratum L.

Knawel Scleranthus annuus L.

Lambsquaters Chenopodium album L.

Lance-leaved coreopsis Coreopsis lanceolata L.

Large crabgrass Digitaria sanguinalis (L.) Scop.

Leadplant Amorpha canescens Pursh
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Leafy spurge Euphorbia esula L.

Least hop clover Trifolium dubium Sibth.

Little barley Hordeum pusillum Nutt.

Little bluestem Schizachyrium scoparium (Michx.) Nash

Little bluestem Schizachyrium scoparium (Michx.) Nash var. scoparium

Little foxtail Alopecurus carolinianus Walter

Longleaf pine Pinus palustris Mill.

Lopsided Indiangrass Sorghastrum secundum (Elliott) Nash

Lyre-leaf Sage Salvia lyrata L.

Maize Zea mays L.

Marshhay cordgrass Spartina patens (Aiton) H.L. Muhl.

Meadow beauty Rhexia mariana L.

Meadow fescue Festuca pratensis Huds.

Millet Pennisetum spp.

Miscanthus Miscanthus sinensis Andersson

Mouse-eared chickweed Cerastium arvense L.

Multiflora rose Rosa multiflora Thunb.

Napier grass Pennisetum purpureum Schumach.

Natalgrass Melinis repens (Willd.) Zizka

New England aster Aster novae-angliae L.

Oats Avena sativa L.

Old-field cinquefoil Potentilla simplex Michx.

Orchardgrass Dactylis glomerata L.

Partridge-pea Chamaecrista fasciculata (Michx.) Greene

Perennial ryegrass Lolium perenne L.

Pigweed Amaranthus viridis L.

Plains coreopsis Coreopsis tinctoria Nutt.

Plantain Plantago sp.

Poison ivy Toxicodendron radicans (L.) Kuntze

Potato Solanum tuberosum L.

Poverty oatgrass Danthonia spicata (L.) P. Beauv. ex Roem. & Schult.

Prairie cordgrass Spartina pectinata Link

Prairie sandreed Calamovilfa longifolia (Hook.) Scribn.

Prairie three awn Aristida oligantha Michx.

Purple coneflower Echinacea purpurea (L.) Moench

Purpleosier willow Salix purpurea L.

Purpletop Tridens flavus (L.) Hitchc.

Red clover Trifolium pratense L.

Red fescue Festuca rubra L.

Red pine Pinus resinosa Aiton

Red spruce Picea rubens Sarg.

Redtop Agrostis gigantea Roth

Reed canarygrass Phalaris arundinacea L.

Rice Oryza sativa L.

Rivercane Arundinaria gigantea (Walter) Muhl.

River oats Chasmanthium latifolium (Michx.) H.O. Yates

Round-headed bush clover Lespedeza angustifolia (Pursh) Elliott

Rough blazingstar Liatris aspera Michx.

Rush Juncus effusus L.

Saltmeadow cordgrass Spartina patens (Aiton) H.L. Muhl.

Sand bluestem Andropogon hallii Hack.

Sand Dropseed Sporobolus cryptandrus (Torr.) A. Gray

Sand lovegrass Eragrostis trichodes (Nutt.) A.W. Wood

Sea oats Uniola paniculata L.

Sheep fescue Festuca ovina L.

Sheep sorrel Rumex acetosella L.
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Showy Tick Trefoil Desmodium canadense (L.) DC.

Sideoats grama Bouteloua curtipendula (Michx.) Torr.

Sky Blue aster Aster oolentangiensis Riddell

Slender wildoats Chasmanthium laxum (L.) H. O. Yates

Smooth aster Aster laevis L.

Smooth cordgrass Spartina alterniflora Loisel.

Smooth bromegrass Bromus inermis Leyss.

Sorghum-sudangrass Sorghum x drummondii (Nees ex Steud.) Millsp. & Chase

Sorghum Sorghum bicolor (L.) Moench

Soybeans Glycine max (L.) Merr.

Stout woodreed Cinna arundinacea L.

Sugarcane plumegrass Saccharum giganteum (Walter) Pers.

Sunflower Helianthus annuus L.

Sweet black-eyed susan Rudbeckia subtomentosa Pursh

Sweetgrass Hierochloe odorata (L.) P. Beauv.

Sweet vernal grass Anthoxanthum odoratum L.

Switchcane Arundinaria gigantea (Walter) Muhl.

Switchgrass Panicum virgatum L.

Swamp pink Helonias bullata L.

Swamp rose-mallow Hibiscus moscheutos L. subsp. lasiocarpos (Cav.) O.J.

Blanchard

Sweetgum Liquidambar styraciflua L.

Tall dropseed Sporobolus compositus (Poir.) Merr.

Timothy Phleum pratense L.

Tall fescue Festuca arundinacea Schreb.

Velvetgrass Holcus lanatus L.

Vetch Vicia spp.

Virginia creeper Parthenocissus quinquefolia (L.) Planch.

Virginia pine Pinus virginiana Mill.

Virginia wildrye Elymus virginicus L.

Wall-rue Asplenium ruta-muraria L.

Walter’s millet Echinochloa walteri (Pursh) A. Heller

Weeping lovegrass Eragrostis curvula (Schrad.) Nees

Western wheatgrass Pascopyrum smithii (Rydb.) A. Love

Wheat Triticum aestivum L.

White clover Trifolium repens L.

Wild Bergamot Monarda fistulosa L.

Wild indigo Baptisia tinctoria (L.) R. Br.

Wild onion Allium sp.

Wiregrass Aristida beyrichiana Trin. & Rupr.

Yarrow Achillea millefolium L.

Yellow nutsedge Cyperus esculentus L.

Yellow sorrel Oxalis stricta L.
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Appendix B. Alphabetic List of Scientific Names. Scientific names are in accordance with the

GRIN (Germplasm Resources Information Network) the official ARS site for plant names. More

information on GRIN can be found at: http://www.ars-grin.gov/npgs/. Common names are as

used in this Proceedings.

Scientific Name Common Name

Achillea millefolium L. Yarrow

Agrostis gigantea Roth Redtop

Allium sp. Wild onion

Alopecurus carolinianus Walter Little foxtail

Amaranthus viridis L. Pigweed

Ammophila breviligulata Fernald American beachgrass

Amorpha canescens Pursh Leadplant

Amphicarpaea bracteata (L.) Fernald Hog peanut

Amphicarpum muhlenbergianum (Schult.) Hitchc. Blue maidencane

Andropogon gerardii Vitman Big bluestem

Andropogon glomeratus (Walter) Britton et al. Bushy bluestem

Andropogon glomeratus (Walter) Britton et al. 

 var. glaucopsis (Elliott) C. Mohr Chalky bluestem

Andropogon hallii Hack. Sand bluestem

Andropogon ternarius Michx. Split beard bluestem

Andropogon virginicus L. Broomsedge bluestem

Anthoxanthum odoratum L. Sweet vernal grass

Apocynum cannabinum L. Dogbane

Aristida beyrichiana Trin. & Rupr. Wiregrass

Aristida oligantha Michx. Prairie three awn

Aristida purpurascens Poir. Arrowfeather

Arundinaria gigantea (Walter) Muhl. Rivercane or switchcane

Asclepias exaltata L.

Asclepias tuberosa L. Butterfly milkweed

Asplenium ruta-muraria L. Wall-rue

Aster ericoides L. Heath aster

Aster furcatus E.S. Burgess Aster

Aster laevis L. Smooth aster

Aster novae-angliae L. New England aster

Aster oolentangiensis Riddell Sky Blue aster

Avena sativa L. Oats

Baptisia tinctoria (L.) R. Br. Wild indigo

Bidens aristosa (Michx.) Britton Bur marigold

Bothriochloa caucasica (Trin.) C.E. Hubb. Caucasian bluestem

Bouteloua curtipendula (Michx.) Torr. Sideoats grama

Bouteloua gracilis (Kunth) Lag. ex Griffiths Blue grama

Bromus pubescens Muhl. ex Willd. Canada brome

Bromus inermis Leyss. Smooth bromegrass

Calamagrostis canadensis (Michx.) P. Beauv. Canada bluejoint

Calamovilfa longifolia (Hook.) Scribn. Prairie sandreed

Chamaecrista fasciculata (Michx.) Greene Partridge-pea

Chasmanthium latifolium (Michx.) H.O. Yates River oats

Chasmanthium laxum (L.) H.O. Yates Slender wildoats

Chenopodium album L. Lambsquaters

Cinna arundinacea L. Stout woodreed

Clarkia tembloriensis Vasek

Coelorachis cylindrica (Michx.) Nash Carolina jointtail grass

Coreopsis lanceolata L. Lance-leaved coreopsis

Coreopsis tinctoria Nutt. Plains Coreopsis

Costus allenii Maas Costus
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Cerastium arvense L. Field chickweed

Cynodon dactylon (L.) Pers. Coastal bermudagrass

Cynodon dactylon (L.) Pers. Bermudagrass

Cyperus esculentus L. Yellow nutsedge

Dactylis glomerata L. Orchardgrass

Danthonia spicata (L.) P. Beauv. ex Roem. & Schult. Poverty oatgrass

Delphinium nelsonii Greene Delphinium

Deschampsia flexuosa (L.) Trin. Crinkled hairgrass

Desmanthus illinoensis (Michx.) MacMill. Illinois bundleflower

ex B. L. Rob. & Fernald

Desmodium canadense (L.) DC. Showy Tick Trefoil

Dichanthelium clandestinum (L.) Gould Deertongue

Digitaria sanguinalis (L.) Scop. Hairy crabgrass

Digitaria sanguinalis (L.) Scop. Large crabgrass

Dracopis amplexicaulis (Vahl) Cass. Clasping coneflower

Echinacea purpurea (L.) Moench Purple coneflower

Echinochloa crus-galli (L.) P. Beauv. Barnyardgrass

Echinochloa walteri (Pursh) A. Heller Walter’s millet

Elaeagnus umbellata Thunb. Autumn olive

Elymus canadensis L. Canada wildrye

Elymus hystrix L. Bottlebrush grass

Elymus virginicus L. Virginia wildrye

Eragrostis curvula (Schrad.) Nees Weeping lovegrass

Eragrostis trichodes (Nutt.) A.W. Wood Sand lovegrass

Espeletia schultzii Wedd. Espeletia

Euphorbia esula L. Leafy spurge

Festuca arundinacea Schreb. Tall fescue

Festuca brevipila R. Tracey Hard fescue

Festuca pratensis Huds. Meadow fescue

Festuca rubra L. Red fescue

Festuca rubra var. commutata Gaudin Chewing’s fescue

Festuca ovina L. Sheep fescue

Gentianella germanica (Willd.) Borner ex E. F. Warb Gentianella

Glycine max (L.) Merr. Soybeans

Gossypium hirsutum L. Cotton

Grevillea barklyana F. Muell. ex Benth.

Helianthus annuus L. Sunflower

Helianthus debilis Nutt. Beach sunflower

Helonias bullata L. Swamp pink

Hibiscus moscheutos L.

 subsp. lasiocarpos (Cav.) O.J. Blanchard Swamp rose-mallow

Hierochloe odorata (L.) P. Beauv. Sweetgrass

Holcus lanatus L. Velvetgrass

Hordeum pusillum Nutt. Little barley

Hypoxis decumbens L. Hypoxis

Impatiens capensis Meerb. Jewel weed

Indigofera hirsuta L. Hairy indigo

Ipomopsis aggregata (Pursh) V. E. Grant Ipomopsi

Juncus effusus L. Rush

Koeleria macrantha (Ledeb.) Schult. Junegrass

Liatris aspera Michx. Rough blazingstar

Lathyrus sylvestris L. Flat pea

Leavenworthia crassa Rollins

Lespedeza angustifolia (Pursh) Elliott Round-headed bush clover

Lespedeza capitata Michx. Round-headed bush clover

Lespedeza cuneata (Dum. Cours.) G. Don Bush clover
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Lespedeza hirta (L.) Hornem. Hairy clover

Liquidambar styraciflua L. Sweetgum

Lobelia cardinalis L. Cardinal flower

Lolium multiflorum Lam. Annual ryegrass

Lolium perenne L. Perennial ryegrass

Lonicera japonica Thunb. Japanese honeysuckle

Lotus corniculatus L. Birdsfoot trefoil

Lupinus subcarnosus Hook. Bluebonnets

Medicago lupulina L. Black medic

Medicago sativa L. Alfalfa

Melinis repens (Willd.) Zizka Natalgrass

Miscanthus sinensis Andersson Miscanthus

Monarda fistulosa L. Wild Bergamot

Oryza sativa L. Rice

Oxalis stricta L. Yellow sorrel

Panicum amarum Elliott Coastal panic grass

Panicum amarum Elliott Coastal/Bitter panic grass

 var. amarulum (Hitchc. & Chase) P. G. Palmer 

Panicum anceps Michx. Beaked panicum

Panicum coloratum L. Kleingrass

Panicum capillare L.

Panicum dichotomiflorum Michx. Fall panicum

Panicum miliaceum L.

Panicum laevifolium Hack.

Panicum virgatum L. Switchgrass

Parthenocissus quinquefolia (L.) Planch. Virginia creeper

Pascopyrum smithii (Rydb.) A. Love Western wheatgrass

Paspalum floridanum Michx. Florida paspalum

Pennisetum spp. Millet

Pennisetum flaccidum Griseb. Carostan flaccidgrass

Pennisetum purpureum Schumach. Napier grass

Phalaris arundinacea L. Reed canarygrass

Phleum pratense L. Timothy

Phlox drummondii Hook. Drummondii phlox

Picea rubens Sarg. Red spruce

Pinus palustris Mill. Longleaf pine

Pinus resinosa Aiton Red pine

Pinus virginiana Mill. Virginia pine

Pityopsis graminifolia (Michx.) Nutt. Grass-leaved golden aster

Plantago sp. Plantain

Plantago lanceolata L. English plantains

Poa pratensis L. Kentucky bluegrass

Potentilla simplex Michx. Old-field cinquefoil

Rhexia mariana L. Meadow beauty

Rosa multiflora Thunb. Multiflora rose

Rubus sp. Blackberry

Rudbeckia hirta L. Blackeyed Susan

Rudbeckia subtomentosa Pursh Sweet black-eyed susan

Rudbeckia triloba L. Brown-eyed susan

Rumex acetosella L. Sheep sorrel

Salix x cottetii Jos. Kern Dwarf willow

Salix purpurea L. Purpleosier willow

Saccharum alopecuroideum (L.) Nutt.

Saccharum brevibarbe (Michx.) Pers. Browncane plumegrass

Saccharum giganteum (Walter) Pers. Sugarcane plumegrass

Salvia lyrata L. Lyre-leaf sage
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Schizachyrium scoparium (Michx.) Nash Little bluestem

Schizachyrium scoparium

subsp. littoralis (Nash) Gandhi & Smeins Coastal little bluestem

Schizachyrium scoparium (Michx.) Nash

Subsp. scoparium Little bluestem

Scleranthus annuus L. Knawel

Setaria spp. Green and yellow foxtails

Setaria faberi R. Herrm. Giant foxtail

Silene alba (Mill.) E. H. L. Krause

Smilax sp. Greenbriar

Solanum carolinense L. Horse nettle

Solanum tuberosum L. Potato

Solidago spp. Goldenrods

Solidago canadensis L. Canadian goldenrod

Sorghastrum nutans (L.) Nash Indian grass

Sorghastrum secundum (Elliott) Nash Lopsided Indiangrass

Sorghum x drummondii (Nees ex Steud.)

Millsp. & Chase Sorghum-sudangrass

Sorghum bicolor (L.) Moench Sorghum

Sorghum halepense (L.) Pers. Johnsongrass

Spartina alterniflora Loisel. Smooth cordgrass

Spartina patens (Aiton) H.L. Muhl. Marshhay cordgrass

Spartina patens (Aiton) H.L. Muhl. Saltmeadow cordgrass

Spartina pectinata Link Prairie cordgrass

Sporobolus compositus (Poir.) Merr. Tall dropseed

Sporobolus cryptandrus (Torr.) A. Gray Sand Dropseed

Sporobolus indicus var. flaccidus Dropseed

(Roem. & Schult.) Veldkamp

Taraxacum officinale Weber ex F. H. Wigg. Group Dandelion

Toxicodendron radicans (L.) Kuntze Poison ivy

Tridens flavus (L.) Hitchc. Purpletop

Trifolium dubium Sibth. Least hop clover

Trifolium hybridum L. Alsike clover

Trifolium pratense L. Red clover

Trifolium repens L. White clover

Tripsacum andersonii J.R. Gray Gamagrass

Tripsacum dactyloides (L.) L. Eastern gamagrass

Tripsacum floridanum Porter ex Vasey Gamagrass

Tripsacum maizar Hern.-Xol. & Randolph Gamagrass

Tripsacum zopilotense Hern.-Xol. & Randolph Gamagrass

Triticum aestivum L. Wheat

Tsuga canadensis (L.) Carriere Eastern hemlock

Typha latifolia L. Cattail

Uniola paniculata L. Sea oats

Veronica arvensis L. Corn speedwell

Vernonia gigantea (Walter) Trel. ex Branner & Coville Ironweed

Vicia sp. Vetch

Vitis sp. Grape

Zea mays L. Maize, Corn
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Appendix C. List of Participants

ADA, Nancy (301) 405-4367 BELENSKY, Brenda (410) 313-4924

Student - University of Maryland Howard Co. Recreation & Parks

2125 Plant Sciences Building 7120 Oakland Mills Road

College Park, MD 20742 Columbia, MD 21228

ADLER, Paul (304) 725-3451 BENSON, Brinlkley (540) 231-7619

USDA - ARS Virginia Tech

45 Wiltshire Rd. 429 Smyth Hall, Virginia Tech

Kearneysville, WV 25430 Blacksburg, VA 24061-0403

ALBERTS, Gene (573) 882-1144 BERGMANN, Carole (301) 650-4360

USDA - Agriculture Research Service M-NCPPC

269 Ag. Engr. Bldg. University of Missouri 1109 Spring St.

Columbia, MO 65211 Silver Spring, MD 20910

ALBERTS, Susan (301) 714-7211 BOOZE-DANIELS, Jody (540) 231-7175

National Park Service Virginia Tech

PO Box 4, 330 Smyth Hall, Dept. CSES

Sharpsburg, MD 21782 Blacksburg, VA 24061-0404

ALTMAN, Ellie (410) 634-2847 BOWEN, Brian (615) 532-0436

Adkins Arboretum Tennessee Natural Areas

P O Box 100, 401 Church Street

Ridgely, MD 21660 Nashville, TN 37200

ALVES, Mary (301) 867-0964 BRANCH, William (410) 545-8626

Historic St. Mary’s City Maryland State Highway

PO Box 39 707 North Culvert Street

St. Mary’s City, MD 20686 Baltimore, MD 21202

ARRIOJAS, Luis (540) 951-2841 BREWSTER, Chris (423) 751-6783

Virginia Tech Tennessee Valley Authority

300 Houndschase Lane Apt I 1101 Market St. MR 413

Blacksburg, VA 24060 Chattanooga, TN 37402

AUMAN, Brian (717) 627-4440 BUCHANAN, Beth (423) 420-4741

6 South Broad Street 1314 Cherokee Orchard Road

Lititz, PA 17543 Gatlinburg, TN 37738

AYERS, Bruce (607) 562-8404 BURNS, Joe (919) 515-7599

Big Flats PMC North Carolina University

Rd. 1, Box 360 A Box 7620 Dept Crop Science NCSU

Corning, NY 14830-0360 Raleigh, NC 27695

BARKDOLL, Jerry (410) 962-0077 BURNS, Nathan (215) 657-0830

Federal Highway Administration Pennypack Eco. Restoration Trust

10 S. Howard St. #4000 2955 Edge Hill Rd.

Baltimore, MD 21209 Huntington Valley, PA 19006-5099

BARKWORTH, Mary (435) 979-1584 BUSH, Tony (527) 641-4982

Utah State University USDA - NRCS

9305 Old MainHill 7472 Stoll Rd.

Logan, UT 84322-5305 East Lansing, MI 48823

BARTH, Carole (301) 883-5902 CALABRIA, Jon (828) 299-3686

Prince George Dept Env. Resource Scott Melrose & Associates

9400 Peppereon 69 Ambler Rd.

Largo, MD 20711 Asheville, NC 28805

BATTIN, Robert (814) 789-3585 CAPEL, Stephen (804) 598-3706

Erie National Wildlife Refuge Virginia Dept. of Game/Inland Fish

11296 Wood Duck Lane 4792 Anderson Highway

Guys Mills, PA 16327 Powhatan, VA 23139

BEELER, Jenny (423) 436-1707 CARROLL, Dan (716) 948-5182

National Park Service NY Dept. Environmental Cons.

107 Park Headquarters Rd. Box 422

Gatlinburg, TN 37738 Alabama, NY 14003
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CHAPPELL, James (861) 656-3104 DOAK, Sam (540) 231-6482

Clemson University SCES Dept. Virginia Tech University

P & A Building Virginia Tech Univ. dept of CSES, 0404

Clemson University, SC 29634 Blacksburg, VA 24061

CLARKE, Elizabeth (401) 822-8825 DOSS, David (410) 757-0861

USDA - NRCS USDA - NRCS

60 Quaker Lane Suite 46 339 Busch’s Frontage Rd.

Warwick, RI 02886 Annapolis, MD 21404-5534

COBER, Donald (410) 545-8596 DOUGLAS, Joel (662) 675-2588

MD. State Highway Administration USDA - NRCS

707 N Calvert St. 2533 CR 65

Baltimore, MD 21202 Coffeeville, MS 38922

COLEMAN, Courtney DREW, Ian (315) 287-9093

American Cyanamid US Fish & Wildlife Service

2320 Grove Avenue Apt. D 1490 Boland Road

Richmond, VA 23220 Richville, NY 13681

COLLART, Linda (716) 226-2466 DUDA, Halina (914) 256-3000

NY Dept. Environmental Conservation NY Dept. Environmental Conservation

6274 E. Avon-Lima Rd. 21 S. Putt Corners Rd.

Avon, NY 14414 New Paltz, NY 12561

CONLEY, Richard H. (931) 484-9571 DUMROESE, Kas (208) 885-3509

Tennessee Wildlife Resources Agency Native Plants Journal

564 Industrial Blvd. Forest Research Nursery - Univ. of Idaho

Crossville, TN 38555 Moscow, ID 83844-1137

CONNELL, Allan (516) 727-2315 DUNNE, Tim (908) 735-0733

USDA - NRCS USDA - NRCS

Riverhead County CTR Room N210 1322 Rt. 31 Box 3

Riverhead, NY 11901 Annandale, NJ 08801

DARHOWER, Steven (717) 520-2248 DUSABLON, Craig (802) 527-5448

Milton Hershey School Vermont Agency of Transportation

Box #830 133 State Street

Hershey, PA 17033 Montpelier, VT 05633-5001

DAVIS, Kathy (301) 504-8175 DUSTY, Daniel (301) 504-8175

USDA - NRCS - NPMC USDA - NRCS - NPMC

Bldg. 509, East Beaver Dam Rd. Bldg. 509, East Beaver Dam Rd.

Beltsville, MD 20705 Beltsville, MD 20705

DAY, Gus (301) 590-1280 EACKER, Georgia (410) 313-1913

MD. Seed & Environmental Service Maryland Cooperative Extension

706 Orchard Way 3525 Suite L Ellicott Mills County

Silver Spring, MD 20904 Ellicott City, MD 21043

DAY, Sharon (919) 542-3532 EDWARDS, Soctt (662) 675-2588

Mellow Marsh Farm USDA - NRCS - PMC

205 Anolis Rd. 111 Forest Ridge Drive

Pittsboro, NC 27312 Oxford, MS 38655

DENGLER, Elmer (410) 757-0861 ENGLAND, Marilyn (516) 922-3200

USDA - NRCS Nat’l Audubon Society

339 Busch’s Frontage Rd. 134 Cove Road

Annapolis, MD 21401-5534 Oyster Bay, NY 11771

DIBOLL, Neil (609) 829-6367 ENGLERT, John (301) 504-8175

Prairie Nursery USDA - NRCS - NPMC

P O Box 306 Bldg. 509, East Beaver Dam Rd.

Westfield, WI 53964 Beltsville, MD 20705

DICKERSON, John (315) 477-6535 ERNST, Calvin (814) 336-2404

USDA - NRCS Ernst Conservation Seeds, Inc.

441 S. Salina St. Suite 354 9006 Mercer Pike

Syracuse, NY 13202 Meadville, PA 16335
Proceedings of the 2nd Eastern Native Grass Symposium, Baltimore, MD November 1999

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ERNST, Marcia (814) 336-2404 FLINT, Matt (919) 873-2124

Ernst Conservation Seeds, Inc. USDA - NRCS

9006 Mercer Pike 4405 Bland Rd.

Meadville, PA 16335 Raleigh, NC 27609

ESCHEMAN, Robert (609) 561-3223 FRITZ, Rod (402) 867-3771

USDA - NRCS Stock Seed Farms, Inc.

251 Bellevue Avenue 28008 Mill Rd.

Hammonton, NJ 08037 Murdock, NE 68407

EVANS, Griff (410) 337-3659 FROST, Dr. Cecil (919) 685-8688

Biohabitats, Inc. NC Dept. of Ag.

15 W Aylesbury Road PO Box 27647

Timonium, MD 21093 Raleigh, NC 27611

EYRING, Shaun (215) 597-8850 FRYE, Christopher T. (410) 260-8565

National Park Service MD DNR Wildlife/Heritage Div.

200 Chestnut St. Tawes Off. Bldg., E-q

Philadelphia, PA 19106 Annapolis, MD 21401

FABULA, Kevin (410) 329-6466 FUNK, David (301) 403-8195

Signature Horticultural Services University of Maryland

19960 Gore Mill Rd 395 Greenmeade Road

Freeland, MD 21053 College Park, MD 20742

FAIRBAIRN, Cheryl (610) 696-3500 GELBHURD, Diane

Penn State Coop. Extension USDA - NRCS

1001 Westtown Rd. #370, PO Box 2747 PO Box 2890

West Chester, PA 19380-0990 Washington, DC 20013-2890

FAIRBAIRN, Bill (610) 383-9453 GENITO, Dennis (814) 863-2033

Lisnageer Farm USDA - ARS

789 Cedar Knoll Rd. 3702 Curtin Road

Coatesville, PA 19320 University Park, PA 16802

FANNING, Edward (301) 695-2803 GENUA, Steve (202) 388-2623

USDA - NRCS PEPCO

92 Thomas Johnson Dr. 1900 Pennsylvania Ave NE

Frederick, MD 21788 Washington, DC 20068

FARRELL, Kimberly (315) 677-4630 GILBERTSON, Randall (715) 635-3505

NRCS USDA - NRCS

2571 U S Route 11 Ste. #3 117 Timberlans Road

Lafayette, NY 13084 Spooner, WI 54801

FEELY, Joan (202) 245-4512 GILL, Douglas (301) 405-6939

USDA Agriculture Research Service University of Maryland

3501 New York Avenue NE Dept. Biology

Washington, DC 20002 College Park, MD 20742

FIELEY, Mark (814) 336-2404 GILLEY, John (402) 472-2975

Ernst Conservation Seeds, Inc. USDA - Agriculture Research Service

9006 Mercer Pike 251 Chase Hall, University of Nebraska

Meadville, PA 16335 Lincoln, NE 68583-0934

FIGURSKI, Edward (302) 856-3990 GLENNON, Robert (501) 882-0944

USDA - NRCS USDA - NRCS

408 N. DuPont Highway 403 Shiloh Road

Georgetown, DE 19947 McRae, AR 72102

FITCH, Kevin (931) 454-6313 GOVER, Art (814) 863-1184

AEDC/Conservation Arnold AFB Penn State University

1100 Kindel Dr. LMRC, Orchard Rd.

Arnold AFB, TN 37389-1800 University Park, PA 16802

FITZKO, Danielle (410) 758-0166 GRABOWSKI, Janet (662) 675-2588

Maryland Cooperative Extension USDA - NRCS

505 Railroad Ave. Ste. 4 2533 County Road 65

Centreville, MD 21617 Coffeeville, MS 38922-2052
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GRAFTON, Emily (800) 922-3601 HEWITT, Allan (518) 357-2162

Canaan Valley Institute NY Dept. Environmental Conservation

P O Box 673 1150 Westcott Rd.

Davis, WV 26260 Schenectady, NY 12306

GRIFFITH-KEPFER, Sally (302) 678-4182 HILAIRE, Larry (510) 296-6952

USDA - NRCS National Park Service

1203 College Park Dr. Suite 101 294 Old Milford Rd.

Dover, DE 19904-8713 Milford, PA 18357

GRIMES., Chuck (405) 853-2607 HOEY, Susan (603) 679-1587

Grasslander USDA - NRCS

Rt. #2 Box 56 243 Calee Highway

Hennessey, OK 73742 Epping, NH 03042

HAAMID, Joseph (410) 222-7822 HOLLINS, Michael (717) 227-0486

USDA - NRCS Sylva Native Nursery and Seed

2662 Riva Rd. Ste. 150 1683 Sieling Farm Road

Annapolis, MD 20401 New Freedom, PA 17349

HAMILTON, Helen (610) 641-1443 HOOVER, Timothy (717) 520-2248

Assatcague Island Nat’l. Seashore Milton Hershey School

Rt. 611 7206 Nat’l Seashore Lane Box #830

Berlin, MD 21811 Hershey, PA 17033

HAMILTON. Tammy (814) 336-2404 HORN, Floyd (202) 720-3656

Ernst Conservation Seeds USDA - Agricultural Research Service

9006 Mercer Pake Jamie L. Whitten Building, 353-A

Meadville, PA 16335 Washington, DC 16802

HARDESTY, Marianne (302) 832-3100 HUDSON, Franklyn (410) 641-1443

USDA - NRCS National Park Service

6 Peoples Plaza 7206 National Seashore

Newark, DE 19702 Berwyn, MD 21811

HEFFERNAN, Kevin (804) 692-0479 HUFF, David

Virginia Dept. Conservation and Rec. Pennsylvania State University

217 Governor Street Dept. Agronomy

Richmond, VA 23219 University Park, PA 16802

HEFFNER, Randalph (215) 766-8151 HUGHES, Paul (207) 990-9199

Aquasoapes Unlimited. Inc. USDA - NRCS

Box 364 967 Illinois Ave. Ste. 3

Pipersville, PA 18947 Bangor, ME 04401

HEISTER, Kristina (610) 783-1041 HUTTO, Curtis (804) 692-0479

Valley Forge Nat’l Historic Park Virginia Dept. Conservation and Rec.

PO Box 953 217 Governor Street 3rd Floor

Valley Forge, PA 19481-0953 Richmond, VA 23219

HELINSKI, Ron (202) 371-1808 IRELAND, Kelly (410) 758-1671

Wildlife Management Institute USDA - NRCS

1101 14th St. NW Suite 801 505 Railroad Ave. Ste.3

Washington, DC 20005 Centreville, MD 21617

HENSON, James (225) 775-6280 ISAACS, Barry (717) 237-2219

USDA - NRCS USDA - NRCS

P O Box 74490 One Credit Union Place

Baton Rouge, LA 70874 Harrisburg, PA 17110

HEPNER, James (540) 459-3132 JOHNSON, Jon (814) 863-1184

Ford Fairfax SWCD Penn State University

6173 Back Road LMRC, Orchard Rd.

Maurertown, VA 22644 University Park, PA 16802

HERR, Debbie (410) 634-2847 JOHNSON, Kris (423) 436-1707

Adkins Arboretum National Park Service

P O Box 100 107 Park Headquarters Rd.

Ridgely, MD 21660 Gatlinburg, TN 37738
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JUNG, Gerald (843) 681-7905 KOENIG, Stanley (518) 623-3671

Agronomist NY Dept. Environmental Conservation

22 Oyster Bay Place Hudson St. Ext.

Hilton Head, SC 29926 Warrensburg, NY 12885

JURAS, Philip (703) 683-7447 KORBONITS, David (302) 239-4244

Rhodeside & Harwell Inc. Mt. Cuba Ctr./Study Piedmont Flora

320 King St. Suite 202 P.O. Box 3570

Alexandria, VA 22314 Greenville, DE 19807-0570

KARRFALT, Robert KRICHTEN, Randy (717) 338-1514

US Forest Service Gettysburg National Military Park

Route 1 Box 182 B Gettysburg, PA 17325

Dry Branch, GA 31020-9696

KAUFFMAN, Gary (828) 526-3765 KRIZEK, Donald (301) 504-5324

US Forest Service USDA - Climate Stress Lab.

2010 Flat Mountain Rd. Bldg. 046A BARC-West

Highlands, NC 28741 Beltsville, MD 20705-2350

KELLY, Fred (732) 246-1171 KROHN, Alison (701) 231-8509

USDA - NRCS North Dakota State University

1370 Hamilton St. P O Box 5285 Arch. Dept.

Somerset, NJ 08873 Fargo, ND 58105

KELLY, Karen (540) 373-2391 KUJAWSKI, Jennifer (301) 504-8175

Chesapeake Bay Foundation USDA - NRCS - NPMC

522 Willis Bldg. 509, East Beaver Dam Rd.

Fredericksburg, VA 22401 Beltsville, MD 20705

KEMPER, Doral (920) 301-9293 KUST, Kathleen (703) 836-5868

USDA - ARS Treemusic

424 Winding Brook Drive 3104 Rissell Road

Oshkosh, WI 54904 Alexandria, VA 22305-1720

KING, Brandy (301) 504-8175 KWONG, Olivia (202) 452-0392

USDA - NRCS - NPMC Society for Ecological Restoration

Bldg. 509, East Beaver Dam Rd. 1849 C St. NW, LSB-204

Beltsville, MD 20705 Washington, DC 20240

KINIRY, Jim (254) 770-6506 LAKATOSH, John (302) 832-3100

USDA - ARS USDA - NRCS

808 E. Blackland Rd. 6 Peoples Plaza

Temple, TX 76502 Newark, DE 19702

KLINE, Norma (401) 364-9124 LERCH, Virginia (301) 731-5907

U.S. Fish & Wildlife Service Consulting Horticulturist

P O Box 307 6100 84th Avenue

Charlestown, RI 02813 New Carrollton, MD 20784

KLINGELHOFER, William (410) 545-8593 LOHNES, Edward (301) 497-5644

MD. State Highway Administration USDA - BRD

707 N Calvert St. Patuxent Wildlife Research

Baltimore, MD 21202 Laurel, MD 20708

KLINGER, Scott (570) 374-5275 LORENTZEN, Tina (410) 293-1027

Pennsylvania Game Commission US Naval Academy

RD 3 Box 244 E US Naval Academy Code 170 181 Wainwright Road

Middelburg, PA 17842 Annapolis, MD 21403

KLOSTER, Marion (423) 430-4748 LORENZ,. David G. (410) 436-6844

National Park Service U S Army Environmental Center

107 Park Headquarters ERS Road SEIM - AEC - ETD Bldg., E-4430

Gatlinburg, TN 37738 Aberdeen Proving Ground, MD 21010

KNOTT, Bruce (410) 545-8595 LUCZYNSKI, Dan (812) 384-4781

Maryland State Highway Adm. LOD USDA - NRCS

707 North Calvert Street 30 West Indiana Avenue Suite 2

Baltimore, MD 21202 Bloomfield, IN 47424
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LUZADERl, James (410) 479-1202 MCKINLAY, Cheryl (301) 855-0263

USDA - NRCS 5650 Cheryl Lane

640 Legion Rd. Suite 3 Chesapeake Beach, MD 20732

Denton, MD 21629

MACDONALD, James (301) 563-6083 MCLAUGHLIN, Samuel (423) 574-7358

8307 Roanoke Ave. Oak Ridge Regional Nat’l Laboratory

Takoma Park, MD 20912 PO Box 2008 MS 6422

Oak Ridge, TN 37830

MACHOVEC, Steve (315) 477-6528 MCNAMARA, Dan (410) 313-4725

USDA - NRCS Howard Co. Parks

4415 Salina Street 7120 Oakland Mills Rd.

Syracuse, NY 13202 Columbia, MO 21046

MACY, Kenton (217) 345-3901 MELVIN, Norman (301) 497-5933

USDA - NRCS USDA - NRCS - WLI

990 B West State Street 11400 American Holly Dr.

Charleston, IL 61920 Laurel, MD 20708

MAINOLFI, Thomas (828) 665-7234 MELVIN, Renee (410) 758-1671

Carolina Native Landscapes, Inc. USDA - NRCS

913 Sand Hill Rd. 505 Railroad Ave. Ste.3

Asheville, NC 28806 Centreville, MD 21617

MARKHAM, Carol (410) 573-4559 MERTZ, Bruce (301) 405-8762

US - Fish and Wildlife Service University Maryland

177 Admiral Cochrane Drive 2101 Ag Life Science Surge Building

Annapolis, MD 21401 College Park, MD 20742

MASON, Rich (410) 573-4584 MEYER, Dean (301) 776-1690

US - Fish and Wildlife Service Morris and Ritchie & Association

177 Admiral Cochrane Drive Morris & Ritchie Assoc. 9090 Junction Dr., Suite 9

Annapolis, MD 21401 Annapolis Junction, MD 20701

MASTERS, Robert (402) 472-1546 MEYER, Gwen (301) 504-8175

USDA - ARS USDA - NRCS - NPMC

344 Keim Hall, University of Nebraska Bldg. 509, East Beaver Dam Rd.

Lincoln, NE 68583 Beltsville, MD 20705

MATTHEWS, Chris (704) 547-4061 MEYERS, Michael (716) 372-0645

HARP NY Dept. Environmental Conservation

P O Box 655 128 South St.

Newell, NC 28126 Olean, NY 14760

MATTHEWS, James (704) 547-4061 MILLER, Christopher F. (732) 246-1171

HARP USDA - NRCS

PO Box 655 1370 Hamilton St.

Newell, NC 28126 Somerset, NJ 08873

MAXON, Susan (301) 504-9099 MILLER, Joe (717) 520-2248

National Seed Lab Milton Hershey School

Bldg. 306, BARC-E Box #830

Beltsville, MD 20705-2325 Hershey, PA 17033

MAY, Jimmy (270) 781-3091 MITCHELL, Laura (607) 898-3504

Kentucky Dept. Fish and Wildlife U.S. Fish & Wildlife Service

Garm Farm Road 921 Pleasant Valley Rd.

Frankfort, KY 40601 Groton, NY 13073

MCGINNIS, Rob (804) 979-1617 MOHLENHOFF, Carl (718) 816-5253

OCULUS Greenbelt Native Plant Center

218 W. Market St. Ste. #1 3808 Victory Blvd.

Charlottesville, VA 22902 Staten Island, NY 10314

MCKELVEY, Chris (518) 357-2162 MONETTE, D.J. (607) 646-9310

NY Dept. Environmental Conservation U.S. Fish & Wildlife Service

1150 Westcott Rd. 927 N. Main St. Bldg.D-1

Schenectady, NY 12306 Pleasantville, NJ 08232
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MOORE, Ken (919) 962-9457 OHLIGER, Paige (703) 765-6641

North Carolina Botanical Garden Bloomin’ Natives N.H.R. Inc.

CB#3375 Totten Center UNC - C4 7005 Vanderbilt Dr. Ste. 21

Chapel Hill, NC 27599-3375 Alexandria, VA 22307

MOORE, Patty (804) 598-3706 OLDHAM, Kenneth (410) 545-8590

Virginia Dept. of Game/Inland Fish Landscape Operations Division

4792 Anderson Highway 707 N Calvert St. C-304

Pohatan, VA 23139 Baltimore, MD 21202

MORAWE, Rijk (804) 224-1732 OLWELL, Peggy (202) 452-7764

National Park Service Bureau of Land Management

1732 Pope’s Creek Rd. 1849 C St. NW, LSB-204

Washington, VA 22443 Washington, DC 20240

MORGERETH, Edward (410) 337-3659 OSENTON, Peter (301) 497-5644

Biohabitats, Inc. USDA - BRD

15 W Aylesbury Road 11440 Am. Holly Drive

Timonium, MD 21093 Laurel, MD 20708

MORRIS, Daniel (518) 457-0100 OWENS, Lloyd (740) 545-6349

NVS DEC USDA - Agricultural Research Service

50 Wolf Rd. Rm. 290 P O Box 488

Albany, NY 13326 Coshocton, OH 43812

MORRISON, Darrell (706) 542-8293 OWENS, Lowell (301) 345-1572

University of Georgia 119 Northway Road

Environmental Design Greenbelt, MD 20770

Athens, GA 30602

MOSER, Gregory (840) 287-1669 PALAZZO, Antonio (603) 646-4374

USDA - NRCS US - Army CRREL

Culpeper Bldg. Suite 209 1606 Santa Rosa Rd. 72 Lyme Road

Richmond, VA 23229-5014 Hanover, NH 03755

MOSKIEWICZ, Joseph (315) 426-7484 PANCIERA, Mike (606) 986-5596

NY Dept. Environmental Conservation Berea College

615 Erie Blvd. West Berea College of Agriculture

Syracuse, NY 13204 Berea, KY 40404

MYERS, Joel (717) 237-2220 PEREZ, Sergio A. (517) 641-6300

USDA - NRCS USDA - NRCS

One Credit Union Place 7472 Stoll Rd.

Harrisburg, PA 17110 East Lansing, MI 48823

NEEL, Linda (303) 988-1810 PERRY, Matthew (301) 497-5622

NACD Patuxent Wildlife Rescue Center

9150 West Jewell, #102 11410 American Holly Drive

Lakewood, CO 80232-6469 Laurel, MD 20708

NELSON, Nanette (315) 426-7412 PERTRUZZI, Janice (302) 697-2600

NY Dept. Environmental Conservation USDA - NRCS

615 Erie Blvd. West 3500 S. DuPont Highway

Syracuse, NY 13204 Dover, De 19901

NOVICK, Nick (508) 881-1646 PETERSON, Paul (540) 231-9590

Small Plant Landscaping Virginia Technical School

6 Meadowbrook Ln CSES Dept; 422 Smith Hall

Ashland, MA 01721 Blacksburg, VA 24061

NYHOLM, Brad (215) 657-0830 POLLARD, Larry

Pennypack Eco. Restoration Trust Truax Company

2955 Edge Hill Rd. R.Rte 1 Box 106

Huntington Valley, PA 19006-5099 Mendon, MO 64660

O’BRIEN, Kate (603) 431-7511 POOLE, Bill (204) 467-3274

USFWS Ducks Unlimited Canada

336 Nimble Hill Rd. Box 1160

Newington, NH 03801 Stonewall, Manitoba, Canada ROC 270
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POTTER, Steve (518) 457-0100 ROBINSON, Larry (301) 504-2334

Nat’l Assn. Land Reclamationists USDA - NRCS

50 Wolf Rd. 5601 Sunnyside Avenue

Albany, NY 12233-6500 Beltsville, MD 20705-5410

PRESTEMON, Kary (315) 685-4703 ROGERS, Judith (660) 885-7551

Essential Landscaping Sharp Bros. Seed Co.

2664 East Lake Rd. 396 S.W. Davis St

Skaneateles, NY 13152 Clinton, MO 64735

PUPKE, Andi (410) 822-5100 ROOT, Christopher (301) 405-6939

Chesapeake Wildlife Heritage University of Maryland

P O Box 1745 Dept. Biology

Gaston, MD 21601 College Park, MD 20742

PYSHER, Duane (717) 237-2221 RUDY, Susan (202) 690-5164

USDA - NRCS National Park Service

One Credit Union Place #340 1900 Anacostia Dr. SE

Harrisburg, PA 17110-2993 Washington, DC 20020

RASCHKE, Bob (303) 988-1810 SALON, Paul (607) 562-8404

NACD USDA - NRCS

9150 West Jewell, #102 Rd 1 Box 360A R/352

Lakewood, CO 80232-6469 Corning, NY 14830

REDDINGER, Becky (301) 416-0536 SANDERS, Samuel A. (352) 338-9547

NPS - Catoctin Mountain Park USDA - NRCS

6602 Foxville Rd. 2614 NW 43rd St.

Thurmont, MD 21788 Gainesville, FL 32006

REEVES, III, James B. (301) 504-8294 SCHAFF, Mary Kay (301) 504-8175

USDA-ARS USDA - NRCS - NPMC

Bldg. 200, Rm. 218 BARC East Bldg. 509, East Beaver Dam Rd.

Beltsville, MD 20705 Beltsville, MD 20705

RHODEN, Errol G. (334) 727-8435 SCHNABEL, Ron (814) 863-8760

Tuskegee University ARS Pennsylvania

Rm 308 Milbank Hall, Tuskegee Past. Syst. & Watershed Mgt. Lab Curtain Rd.

Tuskegee, AL 36088 University Park, PA 16802

RIGHTMIRE, Dianne (607) 562-8404 SCHNAPPINGER, Lee (757) 253-6685

USDA - NRCS - PMC James City County

Box 360 A Route 352 101 East Mounts Bay Road

Corning, NY 14830 Williamsburg, VA 23187-8784

RINGLER, Jason (401) 364-9124 SCHNEIDER, Tina

U.S. Fish & Wildlife Service M - NCPPC

P O Box 307 1109 Spring Street

Charlestown, RI 02813 Silver Spring, MD 20914

RITCHIE, Carole A. (301) 490-3615 SCHRADING. Eric (607) 646-9310

Botanical Consultant U.S. Fish & Wildlife Service

Laurel, MD 20708 927 N. Main St. Bldg.D-1

Pleasantville, NJ 08232

RITCHIE, Jerry C. (307) 504-8717 SCHREIER, Beth (716) 394-0525

USDA - Agriculture Research Service USDA - NRCS

Rm. 110, Bldg. 7, BARC-West 2531 Rochester Road

Beltsville, MD, MD 20705 Cananoaigua, NY 14424

RIVERE, Mike (570) 842-7631 SCHWET, Gary (302) 658-6262

Ecoscience Delaware Cntr. Horticulture

RR 4 Box 4294 1810 N. DuPont St.

Moscow, PA 18444 Wilmington, DE 19806

RIZZO, Al (410) 573-4543 SCULLY, Doris (812) 829-2605

US - Fish and Wildlife Service USDA - NRCS

177 Admiral Cochrane Drive RR 5 Box 102

Annapolis, MD 21401 Spencer, IN 47460
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SEAMON, Greg (850) 643-2756 STRINGER, Bill (864) 656-3527

The Nature Conservancy CSES Dept. - Clemson University

P O Box 393 275 P and A Building

Bristol, FL 32321 Clemson, SC 27634-0359

SHARP, Curtis (304) 876-3189 STROTHER, Jessica (703) 323-5278

Rd 3, Box 695 Virginia Native Plant Society

Harpers Ferry, WV 25425 6004 Windward Dr.

Burke, VA 22015

SHEA, Ernie SWAIN, Robert (732) 928-0600

NACD The Dawson Corporation

509 Capitol Ct. NE P O Box 400

Washington, DC 20002 Clarksburg, NJ 08510

SHEA, Patrick (202) 208-3840 SWANSON, David (919) 967-3355

Department of Interior Swanson Landscape Architect

1849 C St. N.W. 431 West Franklin Street #13

Washington, DC 20240 Chapel Hill, NC 27516

SIMMONS, Cheryl (410) 465-3180 SWARTZ, Harry (301) 405-4367

USDA - NRCS University of Maryland

9025 Chevrelet Dr. Ste. J Plant Sciences Bldg.

Ellicott City, MD 21042 College Park, MD 20742

SIMMONS, Rod SWEARINGEN, Jill (202) 342-1443

MD Native Plant Society US National Park Service

PO Box 4877 4598 Mac Arthur Blvd NW

Silver Spring, MD 20914 Washington, DC 20007

SLATTERY, Britt (410) 573-4581 TALMAGE, Ellen (516) 727-0124

US - Fish and Wildlife Service H. R. Talmage & Son

177 Admiral Cochrane Drive 2075 Sound Ave.

Annapolis, MD 21401 Riverhead, NY 11901-1114

SMITH, Gary P. (717) 237-2204 TANGREN, Sara (703) 765-6641

USDA - NRCS Bloomin’ Natives N.H.R. Inc.

One Credity Union Pl. Ste. 340 7005 Vanderbilt Dr. Ste. 21

Harrisburg, PA 17110 Alexandria, VA 22307

SOTO-GRAJALES, Noel (717) 237-2233 TAYLOR, Richard (302) 831-1383

USDA - NRCS University of Delaware

One Credit Union Place #340 Univ. of Delaware - Dept. of Plant & Soil Sciences

Harrisburg, PA 17110-2993 Newark, DE 19717-1303

STAVER, K.W. (410) 827-8056 TEELS, Billy (301) 497-5938

University of Maryland Wetland Science Institute

PO Box 169 11400 American Holly Drive

Queenstown, MD 21658 Laurel, MD 20708-4014

STEBLEIN, Paul (609) 652-1665 THOMPSON, Louisa (410) 313-2711

U.S. Fish & Wildlife Service Maryland Cooperative Extension

P O Box 72 3525 l Ellicott Mille Drive

Oceanville, NJ 08231 Ellicott City, MD 20143

STEELE, Owen (705) 721-4444 TISCHLER, Charles (254) 770-6523

Ducks Unlimited - Canada USDA - ARS

566 Welham Rd RR8 808 E Blackland Road

Barnie, Ontario, Canada L4N827 Temple, TX 76502

STEUCEK, Guy (717) 872-3789 TOTH, Edward (718) 816-5253

Millersville University Greenbelt Native Plant Center

Millersville, PA 17551 3808 Victory Blvd.

Staten Island, NY 10314

STOCK, Dave (402) 867-3771 TROST, David (518) 897-1305

Stock Seed Farms, Inc. NY Dept. Environmental Conservation

28008 Mill Rd. Rte 86 P O Box 296

Murdock, NE 68407 Ray Brook, NY 12977-0296
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TRUMBULE, Robert (301) 927-8355 WHITE, Dr. Rick (202) 720-0536

Maryland Department Agriculture USDA - NRCS

6701 Lafayette Avenue P O Box 2840, Room 6154, South Bldg.

Riverdale, MD 20737 Washington, DC 20013

TYNDALL, Wayne (410) 634-2348 WHITTEMORE, Ray (603) 487-2175

Maryland Dept. Natural Resources Ducks Unlimited

909 Main St. 122 Joe English Road

Wye Mills, MD 21679 New Boston, NH 03070

UGIANSKY, RJay (301) 504-8175 WILD, Tim (410) 545-8577

USDA - NRCS - NPMC MD. State Highway Administration

Bldg. 509, East Beaver Dam Rd. 707 N Calvert St.

Beltsville, MD 210705 Baltimore, MD 21202

UNDAYAG, Lina (301) 504-8175 WILKINSON, Michele (608) 847-7221

USDA - NRCS - NPMC USDA - NRCS

Bldg. 509, East Beaver Dam Rd. 220 LaCrosse Street

Beltsville, MD 210705 Mauston, WI 53948

VAN DER GRINTEN, Martin (607) 562-8404 WILLEFORD BAIR, Mary (540) 999-3490

USDA - NRCS USDA - National Park Service

Rd 1 Box 360A R/352 3655 US Highway 211 East

Corning, NY 14830 Luray, VA 22835

VANDEVENDER, John (304) 445-3005 WILTBANK, Thomas (302) 697-2600

USDA - NRCS USDA - NRCS

PO Box 390 3500 S. DuPont Highway

Alderson, WV 24910 Dover, De 19901

VASSAR, Wayne (660) 885-7551 WOLF, Dale (540) 231-9741

Sharp Bros. Seed Co. Virginia Tech

396 SW Davis St. CSES VA Tech

Clinton, MO 64735 Blacksburg, VA 24061

VENEZIA, Kathy (718) 816-5253 WOLINSKI, Jeffrey (470) 329-2277

Greenbelt Native Plant Center 18941 Middletown Rd.

3808 Victory Blvd. Parkton, MD 21120

Staten Island, NY 10314

VOLLMER, Jennifer L. (307) 755-5218 ZAYKOSKI, Jerome (315) 785-2293

American Cyanamid NY Dept. Environmental Conservation

2166 North 15th Street 317 Washington St.

Laramie, WY 82072 Watertown, NY 13601

WAGGONER, Mark (410) 757-0861 ZOBEL, Richard (304) 256-2825

USDA - NRCS USDA-ARS-AFSRC

339 Busch’s Frontage Road 1224 Airport Road

Annapolis, MD 21401 Beaver, WV 25813

WALKER, Lou (800) 873-3321

Ernst Conservative Seeds

9006 Mercer Pike

Meadville, PA 16335

WARD, Wendy (603) 756-2988

USDA - NRCS

Route 1 Box 315

Walpole, NH 03608

WASHBURN, Brian (606) 257-7502

University of Kentucky

123 T.P. Cooper Bldg.

Lexington, KY 40546-0073

WEANER, Larry (215) 836-1051

Larry Weaner Land Design

804 Bethlehem Pike

Erodenheim, PA 19038
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Appendix D. Program Planning Committee for the Second Eastern Native Grass Symposium

held in Baltimore, Maryland, November 17-19, 1999.

Co-Chairs

John Dickerson USDA Natural Resources Conservation Service

Gwen C. Meyer USDA Natural Resources Conservation Service

Robert Raschke National Association of Conservation Districts

Jerry C. Ritchie USDA Agriculture Research Service

Committee Members

Jenny Beeler USDI National Park Service

John Englert USDA Natural Resources Conservation Service

Calvin Ernst Ernst Conservation Seeds

Kris Johnson USDI National Park Service

Gary Kauffman USDA Forest Service

Jennifer Kujawski USDA Natural Resources Conservation Service

Dianne Rightmire USDA Natural Resources Conservation Service

Matt Sanderson USDA Agriculture Research Service

Ron Schnabel USDA Agriculture Research Service

Owen Steele Ducks Unlimited-Canada

Lina Undayag USDA Natural Resources Conservation Service

Martin van der Grinten USDA Natural Resources Conservation Service

Mark Waggoner USDA Natural Resources Conservation Service

Brent Wark Ducks Unlimited-Canada