bluuebunny/crossref_metadata_2025 huggingface dataset:
Florida Commercial Horticultural Production: Constraints Limiting Water and Nutrient Use Efficiency
Authors: Stanley Craig D. , Toor Gurpal
Published: December 2018

Application of water and nutrients for horticultural production in Florida can be accomplished through many different methods. Often, the irrigation system that is used determines the potential use efficiency for both water and nutrients. Producers face many constraints, real and perceived, that affect management decisions. This article provides an overview of many of the constraints that are encountered and identifies those management practices that are most effective for overcoming these constraints with respect to commonly used irrigation systems. These constraints include those related to irrigation system design and capabilities, soil factors, cultural practices, management intensity, and economic and regulatory conditions. Ultimately, the goal of this discussion is to determine where future research efforts should be focused and what critical issues may be on the horizon that may affect the Florida horticultural industry.
Horseradish Production in Illinois
Authors: Walters S. Alan , Wahle Elizabeth A.
Published: December 2018

Horseradish (Armoracia rusticana) is a hardy perennial that is grown for its white, fleshy, and pungent roots. Illinois leads the United States in production of horseradish, with ≈1500 acres and an annual farm-gate value of about $10 million, with most processed and added as an ingredient to various commercially produced condiments. Horseradish in Illinois is primarily grown in the Mississippi River Valley region adjacent to St. Louis due to the well-drained, deep friable, high organic matter, moist loam soils that are present in this area. Most of the production is located in Madison and St. Claire counties. This region of southwestern Illinois has been producing horseradish commercially for over 150 years. This review provides an overview of the basics of horseradish production in Illinois, including propagation, cultivars, planting, cultivation, fertilization, pest management, harvest, grading, storage, and marketing. Horseradish is one of the most important specialty crops grown in Illinois, and current and future production concerns are also discussed.
Propagation of Stewartia: Past Research Endeavors and Current Status
Authors: Nair Ajay , Zhang Donglin
Published: December 2018

Stewartias (Stewartia spp.) are prized for their camellia (Camellia japonica)-like flowers, intense fall color, and exfoliating bark. In spite of having outstanding ornamental value and features, these plants are not readily available for landscaping in the horticulture trade. The primary reason stated is the difficulty of its mass propagation and production. In the last two decades, considerable research has been conducted on various aspects of stewartia propagation such as seed germination, cutting type, light, rooting medium, rooting hormone, cold acclimation, and tissue culture. In this article, we discuss factors that directly influence propagation of stewartia and we highlight results of published studies to propagate stewartia. The evidence indicates success in adventitious rooting of cuttings but at the same time recognizes the continuing challenge associated with overwinter survival. Sexual propagation has also been studied, but its commercial application is limited. To date, there is lack of concrete information on why stewartia remains under-represented in our landscapes. It still remains unclear if it is the lack of consumer demand or existing propagation difficulties that is the cause of under utilization of stewartia. Given the information from most published studies, we suggest further research on the aspect of overwinter survival in addition to a survey of the nursery and greenhouse industry to accurately determine the cause behind the absence of stewartia in horticultural trade.
Effects of Shading Using a Retractable Liquid Foam Technology on Greenhouse and Plant Microclimates
Authors: Aberkani Kamal , Hao Xiuming , de Halleux Damien , Dorais Martine , Vineberg Stephen , Gosselin André
Published: December 2018

Climate control is an important aspect of greenhouse crop management. Shading is one popular method for reducing excess solar heat radiation and high air temperatures in the greenhouse during the summer season. A new innovative technology has recently been developed and is based on the injection of liquid foam between the double layers of polyethylene of the greenhouse roof. The foam can be used as a shading method during the warm days of the summer. This is the first investigation into the effect of shading using the liquid foam technology on greenhouse and plant microclimates. Our research was conducted over 2 years in two different areas of Canada. Experimental greenhouses were retrofitted with the new technology. Tomato (Solanum lycopersicum) and sweet pepper (Capsicum annuum) were transplanted. Two shading strategies were used: 1) comparison of a conventional nonmovable shading curtain to the liquid foam shading system and application of liquid foam shading based only on outside global solar radiation; and 2) application of foam shading based on both outside global solar radiation and greenhouse air temperature. Data on the greenhouse microclimate (global solar radiation, air temperature, and relative humidity), the canopy microclimate (leaf and bottom fruit temperatures), and ventilation (opening/closing) were recorded. Our study showed that the retractable liquid foam technology improved greenhouse climate. Under some conditions (very sunny and hot days), a large difference in air temperature (up to 6 °C) was noted between the unshaded and shaded greenhouses as a result of liquid foam application (40% to 65% shading). Foam shading also increased relative humidity by 5% to 12%. Furthermore, bottom fruit temperatures stayed cooler 3 h after shading treatment was stopped. As well, a reduction in ventilation needs was observed with liquid foam shading.
Landscape Preferences and Water Conservation Choices of Residents in a High Desert Environment
Authors: St. Hilaire Rolston , VanLeeuwen Dawn M. , Torres Patrick
Published: December 2018

We surveyed homeowners with residential landscapes in Santa Fe, NM, to determine their attitudes toward high desert plants and to assess their preferences for urban landscapes and water conservation strategies in a high desert urban environment. While there was low acceptance for the traditional turf lawn, 64% of residents agreed that high desert plants provided the variety they needed in their residential landscapes and 92% of residents would use high desert plants to landscape their front yard. Homeowners had a strong preference for retaining their current desert landscapes and converting traditional landscapes to high desert-adapted landscapes. Logistic regression revealed a negative relationship between length of residency in the southwestern United States and the willingness to use high desert plants. When homeowners who irrigated their landscape were asked whether water shortages, environmental concerns, information on water, city regulations, high water bills, or water rate increases would cause them to use less water on their landscapes, the highest level of agreement (94%) was for water shortages. Eighty-eight percent of respondents agreed that they liked any type of landscape that contains interesting features and is well planned. We conclude that homeowners have a preference for desert-adapted landscapes and agree that high desert plants provide an adequate palette of plants for urban landscapes. Additionally, the length of residency in the southwestern U.S. and the possibility of water shortages have the potential to impact water conservation strategies in high desert urban landscapes.
Selective Star-of-Bethlehem Control with Sulfentrazone and Mixtures of Mesotrione and Topramezone with Bromoxynil and Bentazon in Cool-season Turfgrass
Authors: Brosnan James T. , Armel Gregory R. , Klingeman William E. , Breeden Gregory K. , Vargas Jose J. , Flanagan Philip C.
Published: December 2018

Star-of-bethlehem (Ornithogalum umbellatum) commonly invades turfgrass stands throughout the transition zone. Field experiments were conducted to evaluate sulfentrazone and mixtures of mesotrione and topramezone with bromoxynil and bentazon for selective star-of-bethlehem control in cool-season turf. At 4 weeks after treatment (WAT), applications of sulfentrazone at 0.25 and 0.38 lb/acre provided >95% control of star-of-bethlehem in 2008 and 2009. Star-of-bethlehem control following applications of commercial prepackaged mixtures containing sulfentrazone was not significantly different from applications of sulfentrazone alone, at either rate, at 4 WAT in 2008 and 2009. Control with carfentrazone-ethyl at 0.03 lb/acre measured to <75% at 4 WAT each year. Star-of-bethlehem control at 2, 3, and 4 WAT with topramezone at 0.033 lb/acre was increased by 77%, 50%, and 46%, respectively, from the addition of bromoxynil at 0.50 lb/acre. Similarly, the inclusion of bromoxynil at 0.50 lb/acre increased the level of control observed following treatment with mesotrione at 0.28 lb/acre by 77%, 30%, and 32% at 2, 3, and 4 WAT. These data suggest that sulfentrazone and mixtures of topramezone and mesotrione with bromoxynil can be used to provide postemergence control of star-of-bethlehem in cool-season turf.
Performance of Paper Mulches Using a Mechanical Plastic Layer and Water Wheel Transplanter for the Production of Summer Squash
Authors: Coolong Timothy
Published: December 2018

Polyethylene mulches are widely used in vegetable production. Advantages include improving yields, controlling weeds, and enhancing quality. However, the removal and disposal of plastic mulch used for vegetable production represents a significant financial cost for farmers and can be detrimental to the environment. A study was conducted in Fall 2007 and Spring 2008 evaluating the performance of paper mulches for the production of summer squash (Cucurbita pepo ssp. ovifera) ‘Conqueror III’. Four paper mulches, 50-lb kraft paper, 50-lb polyethylene-coated kraft paper, 40-lb white butcher paper, and 30-lb waxed paper were compared with 1-mil black polyethylene mulch, bare-ground hand-weeded, and bare-ground nonweeded treatments. Mulches were placed using a traditional plastic mulch layer and seedlings were transplanted using a water wheel transplanter. Crop yield and quality, weed biomass, soil temperatures under the mulch (Spring 2008 only), and mulch degradation were evaluated. Most paper mulches were able to be placed with a mulch layer, but were not well suited for use with a water wheel transplanter. In Fall 2007, butcher paper and polyethylene-coated kraft paper controlled weeds as well as black plastic mulch. However, in Spring 2008, black plastic mulch provided superior weed control compared with other mulches. Yields among waxed, butcher, and polyethylene-coated kraft papers were similar to black plastic mulch in 2007, though yields in paper mulch plots were significantly less than plastic mulch in Spring 2008. The results of this study suggest that although paper mulches can be effective, cropping conditions and the environment will influence effectiveness.
Irrigation Water and Nitrate-nitrogen Loss Characterization in Southern Florida Nurseries: Cumulative Volumes, Runoff Rates, Nitrate-nitrogen Concentrations and Loadings, and Implications for Management
Authors: Wilson Chris , Albano Joseph , Mozdzen Miguel , Riiska Catherine
Published: December 2018

Enrichment of surface water with nitrate-nitrogen (NO3-N) is a significant problem throughout the world. In support of developing a method for removing NO3-N from water using denitrification, this project characterized runoff events at two nurseries in southern Florida to provide information needed for designing capacity. Specifically, estimates of runoff rates and volumes, NO3-N concentrations and loadings were profiled during intensively sampled fertigation events at a foliage plant nursery and a bedding plant nursery. Discharge volumes and rates varied with event, ranging from 2,487 to 20,935 L and 59.2 to 126 L·min−1, respectively, per event. NO3-N concentrations ranged from 0.7 to 386.4 mg·L−1, and event loadings ranged from 51 to 3024 g, indicating that significant losses may be realized. This project provided valuable hydraulic and chemical loading information needed for the development and design of bioremediation tools for the horticultural industry.
Peel Injury on ‘Gala’ and ‘Golden Delicious’ Apples from Aqueous Hypochlorite Solutions
Authors: Curry Eric A.
Published: December 2018

Experiments were conducted over several years to distinguish symptoms of sodium hypochlorite- or calcium hypochlorite-induced peel injury from other superficial maladies on ‘Gala’ and ‘Golden Delicious’ apples (Malus domestica), and to evaluate factors implicated in injury incidence and severity. ‘Royal Gala’ apples treated by dipping in freshly prepared aqueous sodium hypochlorite for 10 min showed moderate peel injury at the lowest treatment concentration of 150 mg·L−1 when treated immediately after harvest, whereas no injury was observed on fruit treated at even the highest concentration of 2400 mg·L−1 when fruit were kept at −1 °C for 3 months before treatment. At lower rates, rinsing fruit after treatment reduced injury on fruit dipped for 2 min, whereas after a 10-minute treatment, rinsing had no effect. Warm fruit (field heat) generally had a higher incidence of peel injury compared with fruit placed at −1 °C for 24 h before treatment. When ‘Golden Delicious’ apples were treated by dipping for 2 min in freshly prepared aqueous solutions of sodium hypochlorite or calcium hypochlorite at an equimolar hypochlorite ion concentration of 0.008 M (600 mg·L−1 sodium hypochlorite), treatment temperature had a greater influence on incidence of peel injury with sodium hypochlorite than with calcium hypochlorite. Analysis of nonpolar solvent-extractable epicuticular waxes indicated differences due to treatment among several extracted compounds. Microscopic examination of injured peel tissue indicated altered appearance of wax platelets.
Awareness of and Interest in Native Wildflowers among College Students in Plant-related Disciplines: A Case Study from Florida
Authors: Pérez Hector Eduardo , Adams Carrie Reinhardt , Kane Michael E. , Norcini Jeffrey G. , Acomb Glenn , Larsen Claudia
Published: December 2018

Traditional college students do not fit the demographic profile of people who are driving increased sales in gardening and landscaping or the use of native wildflowers. However, today's college students, especially those in plant-related disciplines, may be making future decisions regarding the use of native wildflowers for various applications. Many college students may be unaware of or disinterested in native wildflowers. We used a web-based survey to gauge awareness and interest of native wildflowers in Florida college students enrolled in plant-related disciplines. While students have a generally low awareness of native wildflowers, they expressed high levels of interest in learning more about the identification or cultivation of these species, seeing wildflowers, particularly on their campuses, and using wildflowers in different settings. Students were also interested in purchasing native wildflower seeds or finished plants from local retailers rather than through the Internet. We used student responses from this study to discuss education and marketing opportunities toward native wildflowers.
An Automated Cost-effective System for Real-time Slope Mapping in Commercial Wild Blueberry Fields
Authors: Zaman Qamar Uz , Schumann Arnold Walter , Percival David Charles
Published: December 2018

The development of site-specific agriculture has increased the need for knowledge regarding within-field variability in factors such as soil/plant characteristics and topography that influence wild blueberry (Vaccinium angustifolium) production. Surface soil properties are the first type of information most frequently used by blueberry producers in developing management plans. Topographic features are not yet routinely used to guide within-field management. The majority of blueberry fields in eastern Canada have gentle to severe topography. An automated slope measurement and mapping system (SMMS) consisting of low-cost accelerometers used as tilt sensors, differential global positioning system (DGPS), and laptop and custom software was developed. The SMMS was mounted on an all-terrain vehicle for real-time slope measurement and mapping. Six commercial wild blueberry fields were surveyed in central Nova Scotia to evaluate the performance of SMMS. The automatically sensed slopes (SS) were also compared with manually measured slopes (MS) at 20 randomly selected points in each field to examine the accuracy of SMMS. The SMMS measured slope reliably in the selected fields with root mean square error ranging from 0.12 to 0.56 degrees and correlations of SS with MS of R2 = 0.95 to 0.99. The selected fields had substantial variation in slope (ranging from 0.8 to 31.0 degrees). Therefore, the use of low-cost and reliable accelerometers with a DGPS is a better option than expensive real-time kinematic DGPS for developing cost-effective SMMS to quantify and map slopes (real-time) for planning site-specific management practices in commercial fields. The SS maps or real-time SMMS could also be used to adjust vehicle speed at particularly steep slopes.
Commercial Berry Crop Producers' Production and Marketing Strategies in Virginia
Authors: Monson Joseph , Mainville Denise
Published: December 2018

Producers in Virginia's agriculture sector are searching for alternatives that offer higher returns per acre than traditional commodity production. One possible alternative is the production of berries such as blueberry (Vaccinium spp.), blackberry (Rubus spp.), raspberry (Rubus spp.), and strawberry (Fragaria spp.) that offer a potentially high-value market and can be produced on smaller-scale farms that are characteristic of the state. A mail survey was used to collect data that were analyzed with cluster analysis with respect to farm characteristics, production techniques, marketing strategies, and producers' socioeconomic characteristics. Three types of producers were identified: producers in Cluster 1 are large-scale producers who market the majority of their products through wholesale and retail outlets such as supermarkets, wholesalers, and auctions; producers in Cluster 2 are small-scale, less experienced growers who mostly sell their output directly to consumers, often through farmers' markets; and producers in Cluster 3 are medium-sized, more experienced producers who are also heavily reliant on direct outlets, particularly pick-your-own operations, to sell their products. These characterizations carry implications for extension programming. For example, producers in Cluster 1 have the potential to increase their sales to market outlets, such as supermarkets, that seek larger volumes of production and that have relatively demanding entry requirements; they thus need programming to identify and respond to these needs. Producers in Cluster 2 are relatively new to production and marketing and would benefit from basic programming relating to farm-business planning, production methods, and marketing strategies. Finally, producers in Cluster 3 are distinguished by their diversity and experience in commercial production of berries and would benefit from programming that builds on their considerable experience in and outside of berry production to introduce innovative methods in production and marketing.
Creating the Urban Eden: Sustainable Landscape Establishment in Theory and Practice
Authors: Bassuk Nina , Trowbridge Peter
Published: December 2018

Creating the Urban Eden, a course taught jointly by faculty in Landscape Architecture and Horticulture at Cornell University, is a unique two-semester class spanning the academic year from August to May. Students face the task of creating viable, sustainable landscapes both in theory and practice. The success and sustainability of any planting design is ultimately dependent upon knowledgeable site assessment and analysis, appropriate plant selection, and clear communication of design intentions. This class teaches all aspects of landscape establishment, including detailed site assessment, woody plant identification, choice of appropriate plants, planting design, soil remediation, transplanting, and early maintenance in human-impacted landscapes. In addition to designing for a specific site, students learn about written specifications for technical planting and graphic details to communicate and implement design proposals. Every year on the Cornell University campus, the students in this class implement, in a hands-on manner, all aspects of landscape establishment that they have learned by creating new landscapes that serve to integrate theory, principles, practice, and provide a demonstration of fundamentals taught in the class.
Implementing Sustainable Practices on Campus through Student Independent Study
Authors: Barton Susan S. , Pineo Rebecca S. , Carter Leslie
Published: December 2018

Two students at the University of Delaware participated in independent study projects that helped the University of Delaware campus progress in their efforts to become a sustainable campus. Student projects included a volunteer organization for invasive plant removal, design of a wildlife habitat garden, development of an interpretive signage policy, coordination of publicity, development of interpretive signs, authoring fact sheets, and creation of a sustainable landscapes website. Students benefited from faculty mentoring, collaboration with other university and agency personnel, and real world project coordination. Both students are currently enrolled in graduate programs that will further develop the skills they learned in their independent study projects.
A Tropical Perspective on Environmental Sustainability in Horticultural Education
Authors: Kobayashi Kent D. , Radovich Theodore J.K. , Moreno Brooke E.
Published: December 2018

Curricula in the Department of Tropical Plant and Soil Sciences at the University of Hawai'i at Mānoa were created and modified in the last few years to educate students on topics related to environmental sustainability. New programs included an Organic Food Crop Production course and the Sustainable and Organic Farm Training program. The courses Tropical Production Systems, Vegetable Crop Production, and Weed Science were modified to incorporate concepts of environmental sustainability. The new curricula and modified courses were designed to actively engage students and to promote self-learning through in-depth coverage of sustainable horticultural theory, a hands-on practicum, farm visits, and cocurricular activities. Students were exposed to a broad range of topics, including agroecology, urban agriculture, organic food production, marketing, aquaponics, and landscape ecology from a unique tropical perspective.
Public Gardens: Fulfilling the University's Research Mission
Authors: Meyer Mary Hockenberry , Hokanson Stan , Galatowitsch Susan , Luby James
Published: December 2018

Research at botanic gardens, from medieval times to the present day, has evolved to encompass a wide range of topics. The Minnesota Landscape Arboretum, part of the University of Minnesota, is an example of a diverse, successful research program within a public university garden setting. Collaboration, mission, organization, and publications are keys to a successful research program. Future research for public gardens, including putting collections to work for conservation, understanding global change, ecological genomics, restoration ecology, seed banking, and citizen science are collaborative ideas for all botanic gardens to consider. Research can strengthen the botanic garden's role by providing public value while improving ties to the university.
Survival of Ralstonia solanacearum Race 4 in Drainage Water and Soil and Detection with Immunodiagnostic and DNA-based Assays
Authors: Paret Mathews L. , Kubota Ryo , Jenkins Daniel M. , Alvarez Anne M.
Published: December 2018

Ralstonia solanacearum (Rs) race 4 strains cause bacterial wilt of edible ginger (Zingiber officinale). The survival of the pathogen was studied in plant-free soil and potting medium in the presence of plants inoculated by different methods (non-wounded, rhizome-wounded, and stem-wounded) and irrigated on different schedules (alternate and daily). Detection thresholds for Rs were determined for an enzyme-linked immunoabsorbent assay (ELISA), immunostrip assay, and polymerase chain reaction (PCR) using drainage water from soil and potting medium containing known concentrations of Rs. In the absence of a plant or in the presence of non-wounded plants, Rs populations declined rapidly in drainage water from potting medium during the first 9 days and were undetectable after 81 days. When plants were stem- or rhizome-wounded, Rs populations increased by two to three orders of magnitude from the initial population levels for the first 9 to 19 days and then gradually declined and became undetectable after 89 days. Results were similar in experiments with soil except for non-wounded ginger plants, where the initial decline in Rs populations was followed by an abrupt increase after day 11, reaching 7 log cfu/mL on day 21, then declining gradually to non-detectable levels after 137 days. The increase was attributed to natural infection of the plants followed by release of high populations of Rs into the irrigation water when plants wilted. When rhizome-inoculated plants were watered on alternate days, Rs was recovered from 97 to 129 days in soil and potting medium, but when the plants were watered daily, Rs was recovered in soil and potting medium up to 153 days after plant inoculation. ELISA using Ps1a monoclonal antibody detected the pathogen from >95% of the samples from soil and potting medium when viable populations were >5 log cfu/mL. The immunostrip assay (using the same antibody) detected the pathogen from 100% of the samples when viable populations were >3 log cfu/mL. PCR based on the flagellin gene fliC detected the pathogen from >95% of the samples from soil and from >74% of the samples from potting medium when viable populations were >4 log cfu/mL.
Influence of Aldicarb on Growth and Fruiting of Pecan Transplants
Authors: Wells M. Lenny
Published: December 2018

This study was established to assess the effect of aldicarb on newly transplanted pecan (Carya illinoinensis) nursery trees. Although labeled for use on pecans for more than 25 years, the aldicarb label for pecans was voluntarily dropped by the manufacturer in 2010. Bare-root seedling, ‘Cape Fear’, ‘Sumner’, and ‘Elliott’ trees were planted in Feb. 2007. Ten trees each were treated with one of the following treatments: aldicarb (0.25 lb at budbreak), aldicarb (0.25 lb applied at budbreak and again in June for a total of 0.5 lb/tree), and a nontreated control. Aldicarb increased shoot length, trunk diameter, leaf chlorophyll index, total dry weight, stem dry weight, and root dry weight of pecan seedlings after 1 year's growth. Aldicarb increased trunk diameter of ‘Cape Fear’, ‘Sumner’, and ‘Elliott’ during the course of the study. Nut production of ‘Cape Fear’ was enhanced in the third year of production. These observations indicate that aldicarb is of value in pecan orchard establishment.
In-row Distances and Nitrogen Fertilization Programs for ‘Tasti-Lee’ Specialty Tomato
Authors: Santos Bielinski M. , Scott John W. , Ramírez-Sánchez Maricruz
Published: December 2018

‘Tasti-Lee’™ (‘Fla. 8153’) is the first tomato (Solanum lycopersicum) released in Florida exclusively for the premium specialty market, with characteristic superior flavor and elevated lycopene concentration. Research was conducted to determine the appropriate nitrogen (N) fertilization and in-row distances for ‘Tasti-Lee’ tomato and thus improving the opportunities for successful adoption for this cultivar. Three N fertilization programs and two in-row distances were tested. Total N rates (204, 239, and 274 lb/acre) were the result of the combination of 50 lb/acre of N during prebedding plus each of the following drip-applied N fertilization programs: 1) 1.5 and 2.0 lb/acre per day from 1 to 4 weeks after transplanting (WAT) and 5 to 12 WAT, respectively; 2) 1.5, 2.0, and 2.5 lb/acre per day during 1 to 2 WAT, 3 to 4 WAT, and 5 to 12 WAT; and 3) 1.5, 2.5, and 3.0 lb/acre per day during 1 to 2 WAT, 3 to 4 WAT, and 5 to 12 WAT, respectively. In-row distances were 18 or 24 inches between plants, providing 5808 and 4356 plants/acre. Early and total marketable yields of ‘Tasti-Lee’ tomato were influenced by in-row distances and N fertilization programs, but not by their interaction. The highest early marketable fruit yield was found in plots treated with the highest N rate among fertilization programs (+6%), and in plots planted 18 inches apart (+7%) in comparison with the lowest N rate and the 24-inch spacing. Tomato plots treated with the highest N rate (274 lb/acre) resulted in the largest total marketable yield (+8%). Among the in-row distances, when plants were transplanted 18 inches apart, tomato total marketable yield increased by 18% compared with 24 inches between plants.
Relationship between Soil and Plant Water Status in Wine Grapes under Various Water Deficit Regimes
Authors: Centeno Ana , Baeza Pilar , Lissarrague José Ramón
Published: December 2018

Limited water supply in arid and semiarid Mediterranean environments demands improving irrigation efficiency. The purpose of this study was to determine a functional relationship between soil water availability and wine grape (Vitis vinifera) water status to determine a threshold value of soil matric potential to trigger irrigation. Seasonal trends of soil water potential, leaf water potential, and stomatal conductance (gS) of ‘Tempranillo’ wine grape were determined in two deficit irrigation treatments replenishing 45% and 30% of the reference evapotranspiration, and in a third non-irrigated treatment during 2001 and 2002. Soil water potential was measured with granular matrix soil moisture sensors placed at 0.3 m (Ψ0.3), 0.6 m (Ψ0.6), and 1.2 m (Ψ1.2) depths. The sensors at 0.3 m depth quickly responded to irrigation by increasing Ψ0.3 levels. At the 0.6 m depth, Ψ0.6 progressively decreased, showing significant differences between T1 and the rest of the treatments, while no significant differences in Ψ1.2 were found. All relationships between profile soil matric potential and leaf water potential and gS were highly correlated. After integrating our data with previous studies, we suggest a whole profile soil water potential value of –0.12 MPa as threshold to trigger irrigation and avoid severe water stress during berry growth.
Brief Exposure to Boiling Water Combined with Cold-moist Stratification Enhances Seed Germination of New Jersey Tea
Authors: Stewart J. Ryan , McGary Irene
Published: December 2018

Although there is increasing interest in propagating prairie plants native to the midwestern United States for managed and natural landscapes, several species, including new jersey tea (Ceanothus americanus), are difficult to germinate from seeds. New jersey tea, which is an attractive, compact woody shrub, is found in high-quality prairie remnants throughout the tallgrass prairie region. Developing a protocol to increase the uniformity of seed germination in this species would allow for more widespread horticultural cultivation of this stress-resistant, nitrogen-fixing species. We hypothesized that the germination response of seeds of new jersey tea would be enhanced by replicating conditions that mimic their natural environment, which included treatments under controlled conditions exposing seeds to chilling temperatures, sulfuric acid, and boiling water. Two minutes of exposure to boiling water followed by 60 days of cold-moist stratification at 4 °C resulted in the highest germination percentage (48%) and mean daily germination (2.18 seeds/day). Scarification with 98% sulfuric acid for 15 min followed by 60 days of cold-moist stratification resulted in significant, but lower levels of germination percentage than seeds exposed to boiling water and cold-moist stratification. Cold-moist stratification in darkness and in an 18-hour photoperiod at 4 °C did not stimulate germination to a level suitable for production purposes. However, tetrazolium tests indicated that 79% of the seeds were viable. We conclude that cold-moist stratification should be used with boiling-water or acid-scarification to uniformly produce germinated seedlings of new jersey tea. However, nonresponsive seeds should not be discarded because they may germinate in later years if kept under appropriate conditions.
Management Practices of Growers Using High Tunnels in the Central Great Plains of the United States
Authors: Knewtson Sharon J.B. , Carey Edward E. , Kirkham M.B.
Published: December 2018

A survey was conducted of 81 growers managing 185 high tunnels in Missouri, Kansas, Nebraska, and Iowa to collect information about their high tunnel management practices. The survey was administered from 2005 to 2007 using internet-based and written forms. The average respondent had 4 years of high tunnel experience. The oldest tunnel still in use was 15 years old. Twenty-five percent of respondents grew crops in their high tunnels year-round. Tomato (Solanum lycopersicum), lettuce (Lactuca sativa), spinach (Spinacia oleracea), cucumber (Cucumis sativus), pepper (Capsicum spp.), leafy greens, and flowers were the most common crops. Organic soil amendments were used exclusively by 35% of growers, and in combination with conventional fertilizers by an additional 50% of growers. The summary of management practices is of interest to growers and the industries and university research and extension scientists who serve them. Growers typically reported satisfaction with their high tunnels. Growers with more than one high tunnel had often added tunnels following the success of crop production in an initial tunnel. Labor for crop maintenance was the main limiting factor reported by growers as preventing expanded high tunnel production.
Growth, Flowering, and Cold Hardiness of Rockrose in Western Oregon
Authors: Bell Neil C. , Altland James
Published: December 2018

Ninety-three species, cultivars, and hybrid selections of rockrose (Cistus spp., Halimium spp., and ×Halimiocistus spp.) were evaluated for growth, flowering, and cold hardiness in a landscape trial in Aurora, OR, from 2004 to 2009. Plants were irrigated to aid establishment when planted in summer 2004, but thereafter were not watered, fertilized, or pruned throughout the trial. Cold damage was recorded following freezing events in Feb. 2006 and Dec. 2008 in which low temperatures were 20 and 17 °F, respectively. Those plants that consistently suffered the most cold damage were Halimium atriplicifolium, Cistus creticus ssp. creticus ‘Tania Compton’, Cistus ×pauranthus, and Cistus albidus forma albus. Other plants showed cold damage related to poor vigor. The length of the flowering period and foliage quality varied widely among plants in the evaluation. The plants with the longest flowering period were Halimium ×pauanum, Cistus inflatus, Cistus ×pulverulentus ‘Sunset’, and ×Halimiocistus ‘Ingwersenii’, all of which flowered for more than 55 days. Plant form and foliage quality declined drastically for some plants during the evaluation. Those that retained the best foliage quality included Cistus ×obtusifolius, Cistus ×laxus, Cistus salviifolius ‘Gold Star’, Cistus ‘Gordon Cooper’, Halimium lasianthum ‘Sandling’, Halimium ‘Susan’, and ×Halimiocistus sahucii. Based on ratings of foliage and bloom time, as well as hardiness, several Cistus are recommended as drought-tolerant groundcovers, including Cistus ×gardianus and C. ×obtusifolius. Cistus ×laxus, C. inflatus, Cistus ‘Gordon Cooper’, Cistus ‘Ruby Cluster’, and Cistus ‘Snow Fire’ are suggested as tall groundcovers or landscape specimens. Several Halimium are recommended for landscape use, including H. lasianthum ‘Sandling’, Halimium ‘Susan’, H. ×pauanum, and ×Halimiocistus ‘Ingwersenii’.
North Dakota State University Horticulture and Forestry Program Assessment
Authors: Hatterman-Valenti Harlene
Published: December 2018

Assessment at North Dakota State University is considered to be a conversation about learning outcomes enriched by data with a goal of improving student learning. On the classroom level, this focuses on developing techniques to assess course-related knowledge and skills but may also include techniques to assess learner reactions to teaching and their course-related learning, study skills, and self-confidence. On the program level, this consists of an assessment plan and a corresponding assessment report. These assessment plans identify how the entire curriculum will be assessed over time, whereas the report documents plan implementation. The report consists of the activities designed to collect information on the success of each course. These activities may be direct, indirect, or non-measures of student learning. The direct measures along with a few indirect measures provide answers to the university assessment committee on student learning assessment questions: “what did you do?,” “what did you learn?,” and “what will you do differently as a result of what you learned?”
Student Confidence as a Measure of Learning in an Undergraduate Principles of Horticultural Science Course
Authors: Shoemaker Candice A.
Published: December 2018

Three to five student learning outcomes (SLOs) were written for each of seven units for the Principles of Horticultural Science course, the foundation course for all nine specializations within the undergraduate horticulture program at Kansas State University. The SLOs were then used as the framework for development of the course. A pre- and post-assessment was given to the students enrolled in the course in the fall semesters of 2005 through 2008 in an effort to assess if the SLOs were being met. The 50-item assessment asked students to record their confidence in ability to do something reflective of the SLOs such as “distinguish between transpiration and respiration” or “write a scientific plant name.” The comparison of the student-reported confidence at the start of the course and their academic performance in the course were not correlated. Students' reported confidence at the conclusion of the course was correlated with their academic performance in 3 of the 4 years that were examined. Because confidence was correlated with academic performance in the course and a course would be considered a domain-specific construct, it is more likely that self-efficacy rather than confidence was impacted as the students moved through the course.
Influence of Corn Gluten Meal on Squash Plant Survival and Yields
Authors: Webber Charles L. , Shrefler James W. , Taylor Merritt J.
Published: December 2018

Corn gluten meal (CGM) is a non-selective preemergence or preplant-incorporated herbicide that inhibits root development, decreases shoot length, and reduces plant survival. The development of a mechanized application system for the banded placement of CGM between crop rows (seed row not treated) has increased its potential use in organic vegetable production, especially in direct-seeded vegetables. The objective of this research was to determine the impact of CGM applications (formulations, rates, incorporation, and banded applications) on direct-seeded squash (Cucurbita pepo) plant survival and yields. Neither CGM formulation (powdered or granulated) nor incorporation method (incorporated or non-incorporated) resulted in significant differences in plant survival or squash yields. When averaged across all other factors (formulations, incorporation method, and banding), CGM rates of 250 to 750 g·m−2 reduced squash survival from 70% to 44%, and squash yields from 6402 to 4472 kg·ha−1. However, the banded application (CGM placed between rows) resulted in significantly greater crop safety (75% survival) and yield (6402 kg·ha−1) than the broadcast (non-banded) applications (35% survival and 4119 kg·ha−1 yield). It was demonstrated that banded applications of CGM can be useful in direct-seeded squash production and other organic direct-seeded vegetables.
Pruning of Meadowsweet and Steeplebush
Authors: Stanton Kelly M. , Weeks Sally S. , Dana Michael N. , Mickelbart Michael V.
Published: December 2018

Two native shrubs, meadowsweet (Spiraea alba) and steeplebush (Spiraea tomentosa), are currently grown for use in habitat restoration. Pruning could improve their form and encourage use in more formal gardens. Two seedling populations of each species were grown in the field or in containers outdoors. In Mar. 2009, plants were pruned to 3 or 15 cm or were left unpruned. By midsummer, there was no effect of pruning on plant height in field-grown plants. However, pruning did eliminate lateral growth in field plants and, therefore, improved overall form of the plants. Meadowsweet pruned to 3 cm had about half as many inflorescences as did meadowsweet pruned to 15 cm, with unpruned plants producing an intermediate number of inflorescences. Pruning container plants to 3 cm resulted in plants that were about half the height of unpruned plants, and total biomass was greatly reduced. In general, plants that were pruned had fewer inflorescences, although the total number of inflorescences in all plants was small. Pruning resulted in lower quality plant form in container plants. Species and seed sources within species responded similarly to pruning. Based on the data collected in this study, newly planted meadowsweet and steeplebush should be pruned to achieve good form in the first year. Despite the sometimes leggy growth habit in containers, these species should not be pruned before growing out in the spring, or maximum growth and good form will not be attained.
Growing Minds: Evaluating the Effect of Gardening on Quality of Life and Physical Activity Level of Older Adults
Authors: Sommerfeld Aime J. , Waliczek Tina M. , Zajicek Jayne M.
Published: December 2018

A questionnaire based on the Life Satisfaction Inventory A (LSIA) was used to investigate older adult (age 50+ years) gardeners' and nongardeners' perceptions of personal life satisfaction and levels of physical activity. The LSIA measures five components of quality of life: “zest for life,” “resolution and fortitude,” “congruence between desired and achieved goals,” “physical, psychological, and social self-concept,” and “optimism.” Additional multiple-choice questions were asked to determine respondents' level of physical activity, perceptions of overall health and well-being as well as to gather demographic information. The survey was posted on a university homepage for ≈1 month. Responses were gathered from 298 participants who differentiated themselves as gardeners or nongardeners by responding positively or negatively to the question “do you garden?” Results indicated statistically significant differences in comparisons of overall life satisfaction scores with gardeners receiving higher mean scores indicating more positive results on the LSIA. Four individual quality-of-life statements included in the LSIA yielded statistically significantly more positive answers by gardeners when compared with nongardeners. Other questions regarding healthful practices revealed that personal reports of physical activity and perceptions of personal health were statistically significantly more positive among gardeners when compared with nongardeners.
Broad Mite on Primocane-fruiting Blackberry in Organic Production in Arkansas
Authors: Vincent Christopher I. , García M. Elena , Johnson Donn T. , Rom Curt R.
Published: December 2018

The broad mite (Polyphagotarsonemus latus) was found in association with leaf-curling symptoms on primocane-fruiting blackberry (Rubus rubus) in Arkansas in 2007–2009. Broad mite had not been previously reported on blackberry. The plots sampled in this study were part of a study comparing harvesting in the fall versus harvest in spring and fall, high tunnels versus ambient conditions, and three genotypes, all under organic production. Leaves were sampled, broad mites per leaf counted, and leaf area and trichome density measured. Results indicated that broad mite is capable of overwintering in a moderate temperate climate and that it reduces leaf area of primocane-fruiting blackberry. The fall-only harvest system had fewer broad mites than fall and spring harvest. There were a range of genotype effects on broad mite populations, including one genotype, ‘Prime-Jan®’, on which broad mite populations remained low, and one genotype, APF-46, on which mite populations grew significantly. Observations indicate that the broad mite may be a pest of ‘Prime-Ark® 45’, another primocane-fruiting cultivar.
Overseeding and Trinexapac-ethyl Effects on Tolerance to Simulated Traffic of Four Bermudagrass Cultivars Grown as a Sand-based Athletic Field
Authors: Deaton Michael T. , Williams David W.
Published: December 2018

Common bermudagrass (Cynodon dactylon) and hybrid bermudagrass (Cynodon dactylon var. dactylon × C. transvaalensis) often are used for athletic fields as a result of their wear tolerance and recuperative ability. A wear tolerance study was conducted May 2007 through Nov. 2008 in Lexington, KY. Plots were managed as athletic turf and simulated traffic was applied during the Kentucky high school football seasons. The cultivars Quickstand, Tifway 419, Riviera, and Yukon grown in a sand-based medium were evaluated. Trinexapac-ethyl (TE) was applied at label rates and frequencies or left untreated. Overseeding treatments were perennial ryegrass (Lolium perenne) at 0, 546, and 1093 lb/acre pure live seed. Traffic treatments were applied with a Brinkman traffic simulator three times per week, once each Monday, Wednesday, and Friday, without regard to soil moisture status or weather for the periods 10 Sept. to 2 Nov. 2007 and 12 Sept. to 14 Nov. 2008. In both years of the study, the main effect of cultivar was significant (P < 0.05) in traffic tolerance (‘Tifway 419’ = ‘Riviera’ > ‘Quickstand’ = ‘Yukon’). Overseeding at the medium and high rates also provided significantly greater turf cover for the coarse-textured, more open cultivars (Quickstand and Yukon) over the fine-textured, more dense cultivars (Riviera and Tifway 419). Applications of TE did not significantly improve tolerance to simulated athletic traffic in either year of the study regardless of cultivar or overseeding treatment. Within the parameters of this study, data indicate that only cultivar has significant effects on tolerance to simulated traffic on a sand-based field. Overseeding treatments for the fine-textured, more dense cultivars and TE applications on sand-based field systems had no positive significant effects on tolerance to simulated traffic.