bluuebunny/crossref_metadata_2025 huggingface dataset:
Pre-forcing Treatments Influence Bud Break and Shoot Elongation in Forced Woody Species
Authors: Yang Guochen , Read Paul E.
Published: August 2020

Experiments were conducted to evaluate the feasibility of pre-forcing treatments for the release of bud dormancy of dormant stems of lilac, privet and Vanhoutte spirea. The new softwood growth of these dormant stems was used either as explants for in vitro culture or as cuttings for rooting studies of woody plant species in the off-season. A pre-forcing 15% bleach solution (0.78% NaOCl) soak hastened bud break, enhanced percentage of bud break, and promoted shoot elongation. Pre-forcing wetting agent treatments produced similar results to those of the bleach soak with variation among wetting agents and plant species. Smaller treatment differences were observed in the forcing characteristics when stems were collected later in the winter, probably because the cold requirement of the buds had been completely or partially met. This technique will provide explants for in vitro culture and softwood cuttings for propagation of woody plants over an extended period.
Seed Germination of Pieris floribunda: Influence of Light and Temperature
Authors: Starrett Mark C. , Blazich Frank A. , Warren Stuart L.
Published: August 2020

Seeds of Pieris floribunda (Pursh ex Sims) Benth. and Hook, (mountain andromeda) were germinated at 25°C (77°F) or an 8/16 hr thermoperiod of 25°/15°C (77°/59°F) with daily photoperiods of 0, ½, ½ twice daily, 1, 2, 4, 8, 12, or 24 hr. In seeds exposed to light, germination at 25°C (77°F) began between 3 and 6 days compared to 6 to 9 days at 25°/15°C (77°/59°F), but the delay did not influence cumulative germination. For seeds exposed to light, 30-day germination for equivalent photoperiods at both temperatures was similar. Without light, 30-day germination at 25°C (77°F) and 25°/15°C (77°/59°F) was 38% and 52%, respectively. Daily photoperiods as short as ½ hr increased cumulative germination to 90% at 25°C (77°F) and 25°/15°C (77°/59°F). The remaining light treatments yielded 88 to 95% germination. High germination percentages were due in part to rigorous seed grading prior to initiation of the study.
Postemergence Applied Herbicides for Use On Ornamental Grasses
Authors: Gilliam Charles H. , Keever Gary J. , Eakes D. Joseph , Fare Donna C.
Published: August 2020

Postemergence-applied, grass-active herbicides registered for use in the landscape were applied over-the-top of four ornamental grass species to evaluate tolerance in 1990 and 1991. All herbicides caused some injury to all grass species. Growth indices of dwarf fountain grass (Pennisetum alopecuroides L.K. Spreng. ‘Hameln)’ and pampas grass (Cortaderia selloana Schult. & Schult. f. Asch & Graebn. ‘Rosea’) treated with the low rate of Poast (sethoxydim) was similar to that of the nontreated plants in both years. Acclaim (fenoxaprop-ethyl) caused less injury to purple maiden grass (Miscanthus sinensis Anderss. ‘Purpurescens’) and maiden grass (M. sinensis Anderss ‘Gracillimus’) than Poast and Fusilade 2000 (fluazifop). Both Acclaim rates resulted in similar growth indices to that of nontreated plants. Flowering was reduced in three of the four grass species with all grass active herbicide treatments; the fourth species did not flower.
Effects of Growing Medium, Shade Level and Fertilizer Rate on Cladode Color, Yield and Vase Life of Ruscus hypophyllum
Authors: Stamps Robert H. , Boone Cindy Connery
Published: August 2020

Ruscus hypophyllum L. (Israeli or Holland ruscus) liners were grown from tissue culture in either Florida sedge peat: builders' sand (3:1 by vol) or a commercial soilless medium (Vergro container mix A) until they were large enough to produce harvestable stems for use as cut foliage (florists' greens). Once established, plants were grown in a shadehouse at 50% or 70% shade and were fertilized with either 5, 10 or 15 g (0.18, 0.35 or 0.53 oz) of 17N-2. 6P-10K (17-6-12) controlled-release fertilizer applied every 2 months. Cladode color was not affected by fertilizer level but was affected by both shade level and growing medium, with shade level the more important of the two. Stem numbers and average fresh weight were affected by an interaction of fertilizer rate and growing medium. Maximum stem number occurred at the high fertilizer rate in Vergro and the medium rate in peat:sand while average stem weight was greatest at the high rate in peat:sand and at the medium rate in Vergro. Total stem fresh weight increased as a linear function of fertilizer rate, was 12% higher from peat:sand compared to Vergro, and was 14% greater under 50% compared to 70% shade. There were no commercially significant treatment effects on vase life.
Micropropagation and Field Establishment of Tiarella cordifolia
Authors: Kitto S.L. , Hoopes A.
Published: August 2020

Tiarella cordifolia L. (foamflower) was proliferated on an MS-based nutrient medium. Proliferation was maximal on medium gelled with 0.4% Difco-Bacto agar containing 1.0 mg benzyladenine (BA)/1 and 0 or 0.025 mg naphthaleneacetic acid (NAA)/1. Proliferation of T. cordifolia var. collina was maximal on medium gelled with Gelrite® containing 0.25, 0.5 or 1.0 mg BA/1 plus NAA (0, 0.025, 0.05, 0.1, 0.5 mg/l). Greenhouse rooting and survival was directly related to an increase in microcutting length, whereas leaf number (two to six leaves per microcutting) had no effect. At least 48% of the microcuttings of T. cordifolia inserted directly in the field rooted and survived.
Nontarget Herbicide Losses from Application of Granular Ronstar to Container Nurseries
Authors: Gilliam C.H. , Fare D.C. , Beasley A.
Published: August 2020

With empty containers, nontarget herbicide loss was 23 percent when the containers were spaced container to container. Spacing the containers on 20 (8 in) and 30 cm (12 in) centers resulted in nontarget losses of 51 and 80 percent loss respectively. Nontarget losses were similar when a dense canopy plant (Rhododendron × ‘Trouper’) and an open canopy plant (Berberis thunbergii ‘Crimson Pygmy’) were spaced container to container or on 20 (8 in) or 30 cm (12 in) spacings.
Opportunities for Cooperation between Landscape Contractors and Landscape Architects
Authors: Garber M.P , Bondari K.
Published: August 2020

Landscape architects identified the most common complaints they receive regarding plant material installed in the landscape. The 54 responses from a survey of landscape architects in Georgia were grouped into four categories relating to plant size, plant quality, site preparation and installation, and plant maintenance. Specific opportunities are identified for landscape contractors to help landscape architects address these customer concerns. In addition, landscape architects identified several areas for landscape contractors to assist them in supplying better products and services. These areas include plant material care and availability, close supervision of the installation process, and a closer working relationship between the two groups.
Intermittent Short Days and Chilling, and Benzylaminopurine Affect the Growth and Morphology of Fraser fir Seedlings
Authors: Cazell Ben H. , Seiler John R.
Published: August 2020

Fraser fir (Abies fraseri (Pursh.) Poir.) seedlings were either grown continuously under long days (16 hr) or intermittently exposed to short days (8 hr) to induce bud set followed by a chilling period. Additionally, half the seedlings in each treatment received a foliar application of 444 uM benzylaminopurine (BAP). Seedlings that were allowed to set buds, followed by chilling, obtained the greatest height, but this treatment in combination with BAP reduced seedling height. BAP applied to seedlings grown continuously under long days stimulated height growth and prevented long dormant periods typical for non-chilled seedlings. Continuously grown, BAP-treated seedlings had 1.3 times larger root collar diameter, and 1.7 times more biomass, compared to other treatments. Root/shoot ratios for continuously grown, BAP-treated seedlings were comparable to intermittently chilled, non-BAP treated seedlings. These results suggest that either intermittent short days followed by chilling, or foliar BAP applications can be used to accelerate growth of containerized Fraser fir seedlings. However, the combination of chilling and BAP resulted in poorer development than either treatment alone.
Moisture Stress: An Alternative Method of Height Control to B-nine (daminozide)
Authors: Brown David R. , Eakes D. Joseph , Behe Bridget K. , Gilliam Charles H.
Published: August 2020

Moisture stress was compared to B-nine (daminozide) as a method of height control for annual bedding plant transplants. Three plant species, ‘Big Boy’ tomato, ‘California Wonder’ pepper and ‘Janie Gold’ marigold, were grown in 132 cm3 (8.05 in3) cell packs containing one of 2 commercial media, Fafard #3 or Pro-Mix BX. Treatments included moisture stress (MS), 2 concentrations of B-nine (2500 ppm applied twice and 5000 ppm once), and an untreated control. Method of height control and medium type had an interactive influence on height for each of the 3 species. Moisture stress tomato and marigold were shorter in the Fafard #3 medium compared to those in the Pro-Mix BX medium. Regardless of medium, MS tomato and marigold transplants were shorter or similar in size to the most effective B-nine treatment, 2500 ppm applied twice. Moisture stress and the B-nine treatments for pepper plants grown in the Fafard #3 medium reduced plant height similarly compared to the controls. However, when pepper plants were grown in the Pro-Mix BX medium, only B-nine treatments reduced plant height compared to the controls. Treatments producing short plants did not reduce node number, hence plants appeared fuller than treatments with tall plants. Shoot dry weights for MS tomato and marigold were less than those of plants receiving the other height control treatments, regardless of medium type. Plants of all 3 species grown in the Fafard #3 medium had less shoot dry weight than Pro-Mix BX plants across the 4 height control treatments.
Effect of Fertilizer and Irrigation on Leachate Levels of NH4-N, NO3-N, and P in Container Production of Nephrolepis exaltata ‘Fluffy Ruffle’
Authors: Conover C.A. , Poole R.T.
Published: August 2020

Nitrogen leaching into surficial aquifers continues to become more of a problem in several areas of the U.S., and thus potential for regulation of foliage plant producers is increasing. A factorial experiment evaluated liquid and controlled-release fertilizer sources at three irrigation levels [100, 200, or 300 ml (3.4, 6.8, or 10.2 oz) per 15 cm (6 in) pot twice weekly] for NH4-N, NO3-N, and P in leachate. Samples were collected weekly for 12 weeks beginning the last week of September. Plant grade and top fresh weights were similar for all treatments, but large variations occurred in NH4-N, NO3-N, and P levels in leachate due to irrigation level. Increasing irrigation level above 100 ml (3.4 oz) twice weekly resulted in increases of NO3-N present in leachate, with levels as high as 126 mg/pot observed toward the end of November. NH4-N levels were affected by irrigation during the first seven weeks of the experiment but, after week 2, were lower than one mg/pot. Phosphorus levels ranged from 0.9 to 5.7 mg/pot in leachate with responses to irrigation treatment throughout the experiment.
Determination of Constant-Feed Liquid Fertilization Rates for Spathiphyllum ‘Petite’ and Dieffenbachia ‘Camille’
Authors: Campos Ricardo , Reed David Wm.
Published: August 2020

Spathiphyllum ‘Petite’ and Dieffenbachia ‘Camille’, two popular foliage plants sensitive to excess salts, were grown using 9 levels of water-soluble fertilizer in a 3-1-2 ratio of N-P2O5-K2O. The range for maximum growth occurred at 100–200 ppm (mg/1) N for Spathiphyllum and 200–400 ppm (mg/1) N for Dieffenbachia on a constant-feed basis. Spathiphyllum showed more noticeable leaf bum symptoms compared to Dieffenbachia when the concentration of fertilizer in the irrigation water increased above the range that yielded maximum growth.
Nitrogen Leaching from Osmocote-Fertilized Pine Bark at Leaching Fractions of 0 to 0.4
Authors: Niemiera Alexander X. , Leda Carol E.
Published: August 2020

Pine bark-filled PVC columns with 1 g Osmocote (14N-6.3P-11.6K)(14-14-14) per column were irrigated five days a week for 12 weeks with a leaching fraction (LF) of 0, 0.2, or 0.4. Every two weeks cumulative N content of collected leachate and medium solution N concentration (pour-through method) were determined. The total amount of N leached from bark at 0.4 LF was 61% greater than at 0.2 LF. Medium solution NO3-N concentrations of 0 LF were four to eight times greater than at 0.4 LF for all sampling dates. After 84 days, there was no difference in amount of N remaining in Osmocote prills for the LF treatments.
Nitrate Loading to the Soil Profile Underlying Two Containerized Nursery Crops Supplied Controlled Release Fertilizer
Authors: Brand M.H. , McAvoy R.J. , Corbett E.G.
Published: August 2020

Cornus amomum and Rhododendron ‘Cary's Red’ were grown in #3 (10 1) containers outdoors and supplied with a controlled release fertilizer (CRF). At two week intervals, core samples were removed from the soil underlying the crop at 30 cm (12 in) increments to a depth of 90 cm (36 in). Soil samples and foliar samples were analyzed for nitrate nitrogen (NO3-N) concentration. NO3-N accumulated rapidly in the upper 30 cm (12 in) of soil underlying containerized crops. Accumulation in the 30–60 cm (12–24 in) layer occurred later in the growing season and NO3-N buildup in the 60–90 cm (24–36 in) layer lagged behind both upper soil layers. Maximum NO3-N concentrations exceeded 40 mg/kg (6.36 × 10−4 oz lb−1) of soil and levels above 20 mg/kg (3.18 × 10−4 oz/lb) of soil were sustained throughout the 90 cm (36 in) soil profile for much of the growing season. Patterns of soil NO3-N concentration suggest that, by the middle of the growing season, rapid-growing Cornus may better utilize released N fertilizer than slower growing Rhododendron. Foliar samples confirm significantly higher NO3-N uptake by Cornus than by Rhododendron.
Growth and Flowering Response of Butterfly-Bush to Cutless
Authors: Keever Gary J. , Gilliam Charles H.
Published: August 2020

Buddleia davidii Franch. ‘Royal Red’ (butterfly-bush) was treated with different rates of Cutless (flurprimidol) in two experiments. Growth index, and inflorescence number and index decreased with increasing rates of Cutless. Foliage of treated plants was darker green than that of control plants. Growth inhibition persisted for at least 120 days when plants were treated with rates of 125 to 2000 ppm, but not when treated with 62.5 ppm Cutless. Shoot length measured after the following spring flush was similar among treatments, indicating similar plant vigor.
Response of Tifway Bermudagrass and Tall Fescue Turfgrasses to Preemergence Herbicides
Authors: Johnson B. Jack
Published: August 2020

It is important that preemergence herbicides used for annual weed control in warm- and cool-season turf not injure the desired turfgrass species. A field experiment was conducted for two years to determine the tolerance of Tifway bermudagrass [Cynodon transvaalensis Burtt-Davy x C. dactylon (L.) Pers.] and K-31 tall fescue (Festuca arundinacea Schreb.) to preemergence herbicides. Herbicides were applied at recommended (1X) and twice the recommended (2X) rates. Prodiamine (Barricade) at ≤ 1.6 kg/ha (≤ 1.5 lb/A), butralin (EXP 30910A and EXP 31068A) at ≤ 11.2 kg/ha (≤ 10.1 lb/A), pendimethalin (Pre M and Weedgrass Control) at 3.4 kg/ha (3.0 lb/A), and dithiopyr EC (Dimension) at 0.8 kg/ha (0.75 lb/A) on February 24 did not reduce the quality or shoot density of Tifway bermudagrass. Tifway bermudagrass injured by oxadiazon (Ronstar) ≥ 4.5 kg/ha (≥ 4.0 lb/A) recovered by late April to early May, while turf treated with oxyfluorfen plus oryzalin (Rout) at 2.2 +1.1 kg/ha (2.0 +1.0 lb/A) recovered by late April and turf treated at 4.5 + 2.2 kg/ha (4.0 + 2.0 lb/A) generally did not recover by late June. Tifway bermudagrass treated with oryzalin (Surflan) alone at ≤ 6.7 kg/ha (≤ 6.0 lb/A) did not recover by late June. However, turf treated with benefin plus oryzalin (XL) at 1.7 + 1.7 kg/ha (1.5 + 1.5 lb/A) recovered by this date. None of the preemergence herbicides severely reduced quality or shoot density of tall fescue except oxyfluorfen plus oryzalin (Rout) applied at ≤ 4.5 + 2.2 kg/ha (≤ 4.0 + 2.0 lb/A), oryzalin (Surflan) at 6.7 kg/ha (6.0 lb/A), and benefin plus oryzalin (XL) at 3.4 + 3.4 kg/ha (3.0 + 3.0 lb/A).
Evaluation of Control Strategies for Reducing Rooting-Out Problems in Pot-In-Pot Production Systems
Authors: Ruter John M.
Published: August 2020

Research has shown that a problem in pot-in-pot (PIP) production systems has been the growth of roots out of the planted container, through holes in the holder pot and into the surrounding soil. A study was conducted with Lagerstroemia indica x fauriei ‘Acoma’ to evaluate methods for reducing rooting-out problems in a PIP production system. The products tested were Biobarrier™, a geotextile fabric impregnated with trifluralin; Root Control™ fabric bag material; and Spin Out™, a commercial formulation of copper hydroxide (7.1%) in latex paint. Biobarrier™ reduced plant height, shoot dry weight, percent root dry weight outside of the planted container and total biomass compared to the non-treated control. For the control, 7.1% of the total root dry weight was found between the holder pot and planted container compared to 0.2% for the Biobarrier™ treatment. When the holder pot and planted container or the planted container and Root Control™ fabric were both treated with Spin Out™, plant height and shoot dry weight were reduced. Spin Out™ reduced root circling on the sidewalls of the planted containers but not on the bottom of the containers. All treatments except the control reduced rooting-out to a degree which allowed for the manual harvesting of the planted container from the holder pot after seven months in the field.
Self-watering Container Design and Salinity Affect Growth of Two Foliage Plants
Authors: Martin Chris A. , Borgardt Sandra
Published: August 2020

Dracaena marginata L. and Spathiphyllum Schott. ‘Mona Loa’ were grown for 90 days in either one of two ‘self-watering’ containers, one plastic and one kiln-fired clay. The plastic container relied on the upward movement of water via capillary flow from a subjacent reservoir. The kiln-fired clay container was a ‘pot-within-a pot’ design with an adjacent water reservoir located between the larger and smaller pots. Water seeped horizontally through the inner pot along the pot-rooting medium interface. Reservoirs of each container were filled with either one of three levels of saline water (0.3, 1.3, or 2.3 dS/m). Rooting medium leachate electrical conductivity was lower for ‘pot-within-a-pot’ containers compared with the plastic containers. Irrespective of irrigation salinity, canopy leaf area, root length, shoot to root ratio, gas exchange values, and foliar visual quality of both species were highest for the ‘pot-within-a-pot’ containers. Also, Dracaena leaf area and dry weights were highest for the ‘pot-within-a-pot’ container. Increased irrigation salinity decreased canopy area and visual quality of Spathiphyllum. Shoot dry weight and shoot to root ratio were highest for Dracaena at the 1.3 dS/m salinity level.
Growth Evaluation of the Norway Maple (Acer platanoides L.) Under Different Natural Temperature Regimes
Authors: Richer-Leclerc Claude , Arnold Neville , Rioux Jacques-André
Published: August 2020

Acer platanoides L.(Norway maple) was evaluated for hardiness and growth potential at eight sites in Quebec and one site in North-eastern Ontario over a period of 5 years. Results show that this maple had a low level of mortality at all sites despite very cold conditions and even grew well in Canadian Zones 4 and 5 (USDA Zone 3). However, trees were more severely damaged in Canadian Zone 2a (USDA Zone 2) and cultivation in this area should be avoided. In Canadian Zones 4 and 5. seedlings were only slightly damaged so production is recommended for these areas.
Economic Linkages Between the U.S. Greenhouse and Nursery Products Industry and Landscape Services
Authors: Cox Linda J. , Leones Julie , Hollyer Janies R.
Published: August 2020

Landscape service firms are major purchasers of greenhouse and nursery products in the U.S. The 1985 U.S. Forest Service Impact Analysis for Planning (IMPLAN) input-output model for the state of Arizona was used, along with primary data, to illustrate how to make use of existing data to examine the economic linkages between the landscape services industry group and the greenhouse and nursery products industry. IMPLAN estimated that in 1986 the $247 million of sales made by Arizona landscape service firms stimulated $23.4 million in gross sales for the greenhouse and nursery production sector and $10.5 million in value added. The IMPLAN model is a useful tool for examining the link between landscape service firms and the greenhouse and nursery products industry.
Growth and Fall Color of Red Maple Selections in the Southeastern United States
Authors: Sibley Jeff L. , Joseph Eakes D. , Gilliam Charles H. , Keever Gary J. , Dozier William A.
Published: August 2020

Nine red maple (Acer rubrum L.) cultivars (‘Autumn Flame’, ‘Fairview Flame’, ‘Franksred’, ‘Karpick’, ‘Northwood’, ‘October Glory’, ‘Redskin’, ‘Schlesingeri’, and ‘Tilford’), three Freeman maple (Acer × freemanii, interspecific cross between red maple and silver maple) cultivars (‘Autumn Blaze’, ‘Morgan’, and ‘Scarsen’), and a group of A. rubrum seedlings were evaluated in a field study with trickle irrigation for growth rates and fall color. ‘Autumn Blaze’, ‘Morgan’, ‘Scarsen’, and ‘Autumn Flame’ increased the most in height and diameter annually. Height increase was least for ‘Northwood’. ‘Northwood’ and ‘Karpick’ increased least in diameter annually. Considerable variation in initiation, peak, and duration of fall color, and time of defoliation were evident among cultivars. ‘Fairview Flame’ and ‘October Glory’ exhibited superior fall color while ‘Northwood’, ‘Morgan’, and ‘Redskin’ had poor fall color.
Control of Florida Betony (Stachys floridana Shuttlew.) Emerging From Tubers
Authors: Norcini Jeffrey G. , Aldrich James H. , McDowell Judith M.
Published: August 2020

Derby (metolachlor + simazine), Pennant (metolachlor), and Princep (simazine) were tested at two sites to determine if they would provide control of Florida betony (Stachys floridana Shuttlew.) similar to Barricade (prodiamine). These herbicides were applied twice to containerized Florida betony grown from tubers—a preemergent application in September, 1992 and a postemergent application in November, 1992. Only Barricade (prodiamine) provided 14 weeks of good to excellent control at both sites. Pennant (metolachlor) at 5.4 kg ai/ha (4.8 lb ai/A) provided control equivalent to Barricade (prodiamine) 6 weeks after the initial application at one site and poorer but acceptable control at the other site. Derby (metolachlor + simazine) and Pennant (metolachlor) tended to reduce number of shoots and/or percent coverage compared to an untreated control but generally provided poor control. Princep (simazine) was ineffective.
Tree Transplant Size Influences Post-Transplant Growth, Gas Exchange, and Leaf Water Potential Of ‘October Glory’ Red Maple
Authors: Lauderdale Daniel M. , Gilliam Charles H. , Eakes Donald J. , Keever Gary J , Chappelka Arthur H.
Published: August 2020

Effects of red maple transplant size [3.8 cm (1.5 in, small) and 7.6 cm (3.0 in, large) trunk diameter] on growth were evaluated at park and residential planting sites in Mobile, AL, during 1993 and 1994. Gas exchange and leaf water potential of transplants were monitored. Small trees had greater shoot elongation than large trees during both growing seasons. In 1994, small trees had greater height increases than large trees. Trunk diameter increases of small transplants were twice those of large transplants in 1994. Photosynthesis, leaf conductance, transpiration, and water use efficiency were higher for small transplants than large transplants on every observation date. In August 1993, pre-dawn and daily leaf water potentials were higher (less negative) for small trees than for large trees.
Chemical or Air Root-Pruning Containers Improve Carambola, Longan, and Mango Seedling Root Morphology and Initial Root Growth after Transplanting
Authors: Marler Thomas E. , Willis Dwayne
Published: August 2020

Carambola (Averrhoa carambola L.), longan (Dimocarpus longan Lour.), and mango (Mangifera indica L.) nursery transplants were produced in copper-treated, air-root-pruning (only carambola and mango), or untreated conventional plastic containers during 1990 and 1991. Copper treatments did not influence root growth of carambola or mango; but increased total root growth during container production, the proportion of roots in the upper half of the root system, and new root growth after transplanting for longan. Air-root-pruning containers increased the proportion of roots in the upper half of the rootball and new root growth of carambola and mango following transplanting. Copper-treated containers for longan and air-root-pruning containers for carambola and mango effectively stopped root extension growth at the container wall-medium interface.
A Comparison of Morphological Features Affecting Water Loss in Norway Maple and Washington Hawthorn Stems
Authors: Bates Rick M. , Niemiera Alexander X.
Published: August 2020

Crataegus phaenopyrum (Washington hawthorn) stems are known to be more sensitive to water stress during cold storage than Acer platanoides (Norway maple). Histological examination revealed that maple stems had a highly suberized periderm, and uniform cuticle with few disruptions. Periderm suberization of hawthorn stems was variable and extensive peridermal cracking was evident. Cuticle wax decreased with increasing distance from the stem apex for both species. No differences in lenticellar characteristics were found between species. Results indicated that hawthorn stems had anatomical features that allowed for more water loss than maple stems, which may provide a possible explanation for differences in maple and hawthorn stem water loss rates.
Trade Flows and Marketing Practices within the California Nursery Industry—Survey Results from 1988 and 1993
Authors: Klein Grant J. , Schuch Ursula K.
Published: August 2020

Nurseries were surveyed nationwide in 1989 and 1994 to collect information on products, customers, and business practices during the previous year. California's nursery industry is the largest in the nation and provided the majority of seedlings, liners, whips, and grafted material from within the state. Landscape firms were the most important customers for wholesale nurseries in 1993 (35% of sales), followed by garden centers and re-wholesalers (26% and 25% of sales), and mass merchandisers (12% of sales). Over 90% of California nursery wholesale products were sold within the state, and the rest were shipped to the north, west, midwest, and parts of the east coast. Production cost was used as the most important criteria for price determination of nursery stock. Sales methods such as in-person and telephone, negotiated and non-negotiated sales varied in popularity between the two years surveyed. Nurseries spent about 3.5% of their revenue on advertising, primarily in catalogs and the Yellow Pages. Twenty-six percent and 70% of medium and large nurseries, respectively, were represented at trade shows versus only 11% of small nurseries. Capital and land were the major factors limiting expansion of nurseries in 1988 and 1993, with market demand becoming a more prevalent factor in 1993.
Physical and Chemical Properties of Media Suitable for Containerized Bare Root Whip Production
Authors: Struve Daniel K. , McCoy Edward L.
Published: August 2020

Moisture retention characteristics, pH, cation exchange capacity (CEC) and bulk density of media suitable for containerized bare root whip production and the effects of these media on red oak (Quercus rubra L.) and blackgum (Nyssa sylvatica Marsh.) growth were studied. Media tested were: 3:1:1, 2:1:2 and 2:2:1 (by vol) sand:composted municipal sewage sludge [Comtil]:Isolite or zeolite. A similar series of media were prepared by substituting rice hulls for sand. Similar physical properties were determined for three media components: rice hulls, Comtil and pine bark. Rice hulls and Comtil had high water retention at container capacity, 70.1 and 85.4%, respectively. Thus, substituting rice hulls for sand increased media water retention at container capacity and total plant available water. Media pH ranged from 4.9 (2:1:2 and 2:2:1 rice hulls:Comtil:zeolite) to 6.3 (3:1:1 sand:Comtil:zeolite). Rice hulls and Comtil had bulk densities similar to pine bark (0.30 and 0.32, respectively vs. 0.35 g cm−3); thus, medium bulk density was lower when rice hulls were substituted for sand. Rice hull-based media cation exchange capacity was higher than sand-based media. There were no differences in red oak height growth in the different media; height growth averaged 72 cm (28 in). Blackgum height was greatest (138 cm, 54 in) in 2:2:1 rice hull:Comtil:zeolite medium. The results demonstrate that rice hulls could be substituted for sand without reducing height growth of either species. When grown in the different bare root media, red oak and blackgum seedlings could be bare rooted by hand shaking. The root systems of both species were fibrous with many roots with intact root tips.
Comparison of Conventional and Alternative Nursery Field Management Systems: Tree Growth and Performance
Authors: Calkins James B. , Swanson Bert T.
Published: August 2020

The effects of 5 nursery field maintenance systems (cultivation, herbicide management, legume (bird's-foot trefoil) companion crop, winter cereal (rye) cover crop/mulch, and mixed grass sod) on the growth and performance of field-grown trees were investigated. Six tree species were included in this study: Fraxinus pennsylvanica ‘Marshall's Seedless’; Malus ‘Red Splendor’; Gleditsia triacanthos var. inermis ‘Skyline’; Acer rubrum ‘Northwood’; Thuja occidentalis ‘Techny’; and Picea glauca var. densata. Height, lateral branch extension, and caliper growth were measured each year for 7 years. Plant quality was assessed at the end of the study. All growth parameters were affected by field management treatment. Field management treatment effects on growth were influenced by differences in climate between years and were species dependent. Caliper growth was more sensitive to cover crop competition than height growth. Height and caliper growth were initially reduced for deciduous trees grown together with cover crops, but treatment differences in height became less significant over time. Caliper of evergreens was also reduced, but field management treatment effects on height were variable. Trees grown under bare soil conditions (cultivation and herbicide management) were more densely branched than those grown with cover crops. Herbicide management and cultivation generally supported the most vigorous growth and resulted in the best quality plants. Of the cover/companion crops evaluated, the rye cover crop/mulch treatment only slightly reduced plant performance compared to cultivated and herbicide management treatments while bird's-foot trefoil and grass companion crops proved to be too competitive. A winter rye cover crop/mulch field management system appears to have potential as an alternative to conventional field production systems. Using such a system, quality plants can be produced with fewer inputs and fewer negative impacts on the environment and long term productivity.
Effect of Cold Storage and Pre-transplant Desiccation on Root Growth Potential and Bud Break of Bare-root Washington Hawthorn and Norway Maple
Authors: Bates Rick M. , Niemiera Alexander X.
Published: August 2020

Two-year-old Washington hawthorn (Crataegus phaenopyrum Med.) and Norway maple (Acer platanoides L.) seedlings were subjected to varying cold storage durations and 4 storage treatments: whole plant covered, shoots exposed, roots exposed and whole plant exposed. After storage, half the seedlings were immediately planted and half received a 12-hr desiccation treatment prior to transplanting. Root growth potential (RGP), time to bud break, and marketability were measured. With the root covered treatments, Norway maple RGP increased, while Washington hawthorn RGP decreased with increased cold storage duration. RGP for both species remained low throughout storage for treatments exposing roots. The 12-hr desiccation treatment reduced RGP for both species with hawthorn being more affected than maple. Days to bud break for both species decreased with increased storage time for whole plant covered treatments, but increased for both species when stored with exposed roots. Maple marketability for root covered treatments was high for most storage durations. Hawthorn marketability was generally low except for the whole plant covered treatment during the first 6 weeks of storage. For the respective storage durations, hawthorn RGP, time to bud break and marketability values for the shoots exposed treatment were similar to the roots exposed treatments. In contrast, values for the shoot exposed treatment were similar to the whole plant covered treatment for maple. There was a high positive correlation between RGP and marketability for both species.
Compost and Rubber Tire Chips as Peat Substitutes in Nursery Container Media: Growth Effects
Authors: Calkins James B. , Jarvis Beth R. , Swanson Bert T.
Published: August 2020

This research investigated the feasibility of using composted yard wastes, composted municipal solid waste and shredded rubber tire chips in nursery container media. Containerized Physocarpus opulifolius ‘Dart's Gold’, Forsythia × ‘Meadowlark’, Spiraea × billiardii, Juniperus chinensis ‘Seagreen’, J. sabina ‘Mini Arcade’, J. horizontalis ‘Hughes’, and Lamiastrum galeobdolon were grown in media amended with five recycled waste materials used as peat substitutes in a standard container medium of composted woodchips, peat, and sand (3:2:1 by vol). Waste materials used included three yard waste composts, one municipal solid waste compost and shredded rubber tire chips. Fifty or 100% of the peat in the standard growing medium was replaced with each amendment. Ten treatments (five amendments, each at 50% and 100% peat replacement) and a control (standard medium) were used for all seven plant species. Visual ratings, height and width measurements (crown volume), number of growing points and plant dry weights indicated that media in which 50% of the peat was replaced by an amendment produced larger plants of superior quality compared to the control. Rubber tire chips were acceptable as a 50% peat substitute for plants that prefer well-drained conditions, while 100% peat substitution with tire chips was detrimental to plant growth and performance. Use of immature compost in container media negatively influenced plant growth.
Weed Control in Container-Grown Crops with Herbicide-Coated Fertilizers
Authors: Crossan C.K. , Gilliam C.H. , Keever G.J. , Eakes D.J. , Wehtje G.R. , Dozier W.A.
Published: August 2020

Nursery Special 12N-2.6P-5.0K (12-6-6), Osmocote 17N-3.1P-10.0K (17-7-12), and Polyon 24N-1.7P-10.0K (24-4-12) were coated with Ronstar 50WP (oxadiazon) at 4 concentrations and compared to spray applied Ronstar 50WP and broadcast Ronstar 2G. With Osmocote and Nursery Special-coated fertilizers, the lowest Ronstar rate resulted in less weed control than traditional herbicide application methods. Ronstar-coated fertilizers applied at the recommended rate or higher provided similar weed control to broadcast-and spray-applied pre-emergence herbicides.
Role of Stress in Predisposing Trees to Insect Colonization: Implications for Plant Health Care
Authors: Ball John , McLeod Murdick J.
Published: August 2020

Plant health care is a program of preventive maintenance, based on the use of cultural, biological and chemical tactics, to enhance plant appearance, structure and vitality. Trees planted in the urban landscape are considered to be stressed and predisposed to successful colonization by many insects. This presumption that there is a simple index between vitality and stress, and that stressed trees are predisposed to colonization, may not always be true. The relationship between tree vitality and susceptibility to insect attack is highly complex. Tree susceptibility to insect colonization does not increase continuously with stress. Recent studies have indicated that mild stress may improve tree defenses and that a plant health care strategy aimed at maintaining rapid tree growth may not reduce susceptibility to insects. Extension specialists and researchers need to focus their efforts on understanding tree defense strategies and developing cultural recommendations aimed at improving defenses rather than growth.
Taxane Contents of Taxus Cultivars Grown in American Nurseries
Authors: ElSohly Hala N. , Croom Edward M. , Kopycki Wlodzimierz J. , Joshi Alpana S. , ElSohly Mahmoud A. , McChesney James D.
Published: August 2020

The taxane content of the needles, stems and clippings of 92 cultivars obtained from ten nurseries in the United States is presented. The analysis of 10-desacetyl baccatin III (1), baccatin III (2), 10-desacetyl taxol (3) cephalomannie (4), 10-desacetyl-7-epi-taxol (5) and taxol (6) was carried out using a high performance liquid chromatographic method developed in our laboratory. The total ‘useful’ taxane content of the leaves, stems, and clippings in the studied cultivars ranged from 0.0135–0.1471%, 0.0055–0.0462% and 0.0121–0.1183%, respectively, with 1 and 6 being the most abundant. The survey identified 18 cultivars with a content of 1 ranging from 0.015% to 0.0622% and 24 cultivars with a content of 6 ranging from 0.012% to 0.062%; compound 2 was either undetectable or found in negligible amounts in all the cultivars studied. The contents of 3 varied between 0.0019–0.0264% and that of 4 between 0.0017–0.0386%, while that of 5 between 0–0.0107%.
Offset Increase in Hosta Following Benzyladenine Application
Authors: Keever Gary J. , Brass Thomas J.
Published: August 2020

A single foliar application of benzyladenine (BA) at 1250 to 3750 ppm stimulated axillary and rhizomic budbreak and offset formation in Hosta sieboldiana (Lodd.) Engl. Plants with no initial offsets formed a similar number of offsets as those with one initial offset but 143% more offsets than plants with two or three initial offsets. Growth index was either not affected or increased by BA application. Plant appearance was enhanced by late season offset formation in BA-treated plants.
Review of Customer Preference Research in the Nursery and Landscape Industry
Authors: Barton S.S. , Brooker J.R. , Hall C.R. , Turner S.C.
Published: August 2020

This paper outlines current, descriptive information about the retail plant customer's profile and identifies information needed to complete the profile as well as areas for continued research. Demographic studies that characterize the retail customer base vary with regional market and product lines included in the study. Mass merchandisers attract lower income customers; large, multiple outlet garden centers attract unmarried customers with higher incomes and greater value homes; and independent garden centers attract married, white females. Multiple studies support the conclusion that customers select outlets based primarily on plant quality and selection. Product quality is also the most important characteristic used by retailers when selecting a supplier. Location, price and professional staff also affect outlet selection. Mass merchandisers are selected for familiar, low-risk purchases, while independent garden centers are used for major purchases, when information is desired. The availability of trained, professional sales help is the service most desired by customers. Customers prefer to receive information in the garden center from professional staff and from nursery care tags. Customers prefer to purchase shrubs in containers. In one study, customers preferred to purchase balled and burlapped trees, while in another study trees were preferred in containers. Landscape architects prefer to purchase balled and burlapped plants.
Preventing White Grub Infestation in Container-Grown Nursery Stock
Authors: Nielsen David G. , Cowles Richard S.
Published: August 2020

Preplant media incorporation of Talstar 0.2 G (bifenthrin) at 10 ppm (parts per million) or Fireban 1.5 G (tefluthrin) at 15 ppm, based on dry weight of the medium, provided complete control of Japanese beetle (Popillia japonica Newman), oriental beetle [Exomala orientalis (Waterhouse)], and European chafer [Rhizotrogus majalis (Razoumowsky)] in container nursery plants for two growing seasons. Talstar 0.67 F drenched immediately after planting also prevented establishment of these species in containers for two growing seasons. Marathon 1 G (imidacloprid) preplant media incorporated at 6–17.8 g (a.i.)/m3, provided incomplete control, while Marathon 60 W was completely effective when drenched in mid-summer prior to inoculating the pots with eggs. Other granular products mixed into potting media, including 10 ppm of fipronil or Mach 2, or 150 g (a.i.)/m3 of Lorsban or SuSCon Green, provided good control for one season. Several treatments prevented establishment of Japanese but not oriental beetle grubs. Curative drenches were generally ineffective. Registered treatments providing two years of control (Talstar at 10–25 ppm) can be used by growers to prevent white grub larval establishment in containers. Their usage should allow shipment of treated plants throughout the United States and Canada.
Propagation of Magnolia virginiana ‘Santa Rosa’ by Semi-Hardwood Cuttings
Authors: Griffin Jason J. , Blazich Frank A. , Ranney Thomas G.
Published: August 2020

Terminal, semi-hardwood cuttings (tips of first-order laterals) of Magnolia virginiana L. ‘Santa Rosa’ (‘Santa Rosa’ sweetbay) were collected on November 13, 1997, and treated with 0, 6, 12 or 25 mM (0.0, 0.13, 0.25 or 0.5%) indolebutyric acid (IBA) in factorial combination with equivalent mM concentrations of naphthaleneacetic acid (NAA) (0.0, 0.11, 0.23 or 0.46%). Rooting was maximized (83%) for cuttings treated with 25 mM (0.5%) IBA alone. Percent rooting for treatments of NAA alone or in combination with IBA never exceeded that of IBA alone at 12 or 25 mM (0.25% or 0.5%). Root number and root length were unaffected by any treatment with means of 2.4 roots and 10 cm (4 in), respectively.
Nitrogen Nutrition of Containerized Thuja x ‘Green Giant’
Authors: Griffin Jason J. , Warren Stuart L. , Blazich Frank A. , Ranney Thomas G.
Published: August 2020

Rooted stem cuttings of ‘Green Giant’ arborvitae (Thuja L. x ‘Green Giant’) were grown in 3.8 liter (#1) plastic containers containing a pine bark: sand (8:1 by vol) substrate. Plants were fertilized three times weekly for 15 weeks with a complete nutrient solution at N application rates (NARs) of 0, 10, 20, 40, 80, 160, or 320 mg/liter (ppm) supplied as ammonium nitrate (NH4NO3). Both shoot and root dry weights were significantly affected by NAR. Maximum shoot weight, as predicted by a quadratic plateau model, was reached at a NAR of approximately 100 mg/liter (ppm), representing a 200% increase over controls [0 mg/liter (ppm) N]. Maximum and minimum root dry weights occurred at 0 mg/liter (ppm) N and approximately 50 mg/liter (ppm) N, respectively, representing a 37% decrease. Root length decreased 36% at a NAR of approximately 50 mg/liter (ppm). Root diameter (root area ÷ root length) increased before reaching a plateau at approximately 130 mg/liter (ppm) N indicating that root length decreased faster than root area at low N concentrations. Shoot concentrations of N, P, Mg, and S were maximized at approximately 71,41,48, and 52 mg/liter (ppm) N, respectively. Uptake of K and Ca were unaffected by N concentrations.
Preservation and DNA Fingerprinting of the Historic Tidal Basin Cherries
Authors: Pooler Margaret R.
Published: August 2020

The historic Japanese flowering cherry trees planted around the Tidal Basin in Washington, DC, were given to the United States in 1912 as a gift from Japan, yet only a small portion of the original trees remain. In cooperation with the National Park Service, the U.S. National Arboretum clonally propagated a portion of these trees. DNA from these and other P. x yedoensis plants obtained from domestic commercial nurseries were compared using RAPD markers. Twenty-one 10-nucleotide primers yielded 80 repeatable bands that were used to assess genetic distances among the accessions. The genetic distances ranged from 0.65 to 1.0, with thirteen accessions identical at all loci tested. The most genetically dissimilar trees were P. x yedoensis accessions that were collected as seed in Japan. Accessions obtained from commercial nurseries including ‘Afterglow’, ‘Akebono’, and Yoshino were also dissimilar to the Tidal Basin trees. This study indicated that most of the older trees planted around the Tidal Basin are genetically very similar, but that variability in P. x yedoensis exists, especially in accessions collected as seed from Japan.
Root Mass and BA Affect Offset Formation in Hosta
Authors: Schultz Heather C. , Keever Gary J. , Kessler J. Raymond , Dute Roland R. , Olive John W.
Published: August 2020

A study was conducted to determine the effects of root mass and benzyladenine (BA) on offset formation in hosta. Stock plants of two cultivars, ‘Francee’ and ‘Frances Williams’, were divided, and offsets were placed in either small, medium, or large root mass groups. Offsets were potted and, when surface root development was evident, half of the plants in each root mass group received a foliar spray application of 3000 ppm BA, while half served as BA controls. Offset formation was positively correlated with increasing root mass, regardless of BA application. BA stimulated the outgrowth of axillary and rhizomic buds in both cultivars. Offsets on plants treated with BA were at a more advanced stage of development (SOD) than offsets on BA controls, but root mass did not affect SOD. Root mass, but not BA, affected whole plant growth index, which increased with increases in root mass.
Effect of the Growth Regulator Proxy on Creeping Bentgrass Fairway Turf
Authors: Stier John , Reicher Zac , Hardebeck Glenn
Published: August 2020

Proxy is a newly-labeled plant growth regulator (PGR) for use on golf course and commercial turfgrass areas. Four rates of Proxy (ethephon), 2.3, 3.6, 4.6, and 9.1 kg ai/ha (2.0, 3.2, 4.1, and 8.2 lb ai/A,) were compared to Primo (trinexapac-ethyl) at 1.0 kg ai/ha (0.9 lb ai/A) and an untreated control for clipping reduction and effects on aesthetics of creeping bentgrass maintained as fairway turf. Treatments were applied three times at 28-day intervals during 1998 at locations in Indiana and Wisconsin. Proxy was as effective at reducing clipping yields as Primo, although the magnitude of effects varied between the two locations. In general, Proxy was more likely to reduce turf quality and color than Primo. All rates of Proxy reduced clipping weights similarly, but low rates were less likely to reduce color or quality ratings. Turf density was not affected by Proxy or Primo. Effects of Proxy on creeping bentgrass occurred within two weeks after application and generally dissipated within four weeks, whereas Primo effects occurred within one week after application and generally dissipated within three weeks. Turf quality was occasionally reduced following application of Proxy.