bluuebunny/crossref_metadata_2025 huggingface dataset:
In-row Spacing and Cultivar Affects Ear Yield and Quality of Early-planted Sweet Corn
Authors: Rangarajan Anusuya , Ingall Betsy , Orfanedes Michael , Wolfe David
Published: December 2018

Early-planted fresh market sweet corn (Zea mays) is prone to nonuniform ear length and quality due to uneven germination in cool soils. Growers compensate by reducing in-row spacing at seeding, to increase final plant stand. This risk management strategy was suspected to be reducing quality of early-planted sweet corn, based upon buyer feedback. Four experiments were conducted in upstate New York, to examine the effects of in-row spacing and cultivar on early-planted sweet corn ear yield, length and uniformity. Cultivars examined included `Temptation' (4 years), `Sweet Symphony' (3 years) and `Seneca Spring' (2 years). In-row spacings tested ranged from 6 to 9 inches (15.2 to 22.9 cm), using a 30-inch (76.2-cm) between-row spacing. In-row spacing and cultivar influenced marketable yield, husked ear weight and length of early-planted corn, but the extent varied by year. Despite improvements in individual ear weight and length at wider in-row spacing, marketable yield was usually higher at more narrow spacings. Increases in ear weight at wider spacings were usually associated with increases in weight of the outer, green husk. Average ear length of a cultivar varied between 0.2 and 0.6 inches (0.5 to 1.5 cm) in response to spacing. If ears longer than 7 inches (17.8 cm) were desired, 40% to 60% of ears satisfied this criteria if harvested from plants grown at 8-inch (20.3-cm) in-row spacing or a plant population of 26,000 plants/acre (64,200 plants/ha). Ear weight and length of `Seneca Spring' was not as affected by the in-row spacing treatments compared to the other two cultivars, perhaps due to the small size of this cultivar. Selection of smaller sized sweet corn cultivars for planting at high plant populations (6-inch in-row spacing) may reduce the variation in ear weight under challenging early season conditions. For cultivars with similar growth characteristics and maturities of `Temptation' and `Sweet Symphony,' a minimum in-row spacing of 8 to 9 inches or a plant population of 23,200 to 26,000 plants/acre (57,300 to 64,200 plants/ha) was recommended to minimize variation in ear yield and quality from first bareground plantings in the northeastern United States.
Current Status of Human Issues in Horticulture in Korea
Authors: Kwack Hye Ran , Relf Paula Diane
Published: December 2018

As the level of urbanization has increased, many people in Korea have begun to recognize the beneficial effects of plants in our immediate surroundings and involvement in horticultural activities. Today, an increasing number of Koreans attempt to improve the quality of life and enhance educational effectiveness through horticultural activities. Kindergarten, elementary, middle, and high schools have initiated garden-based programs. Some universities include courses focusing on horticulture applications to human well-being in their regular graduate programs or in their social education curricula. A few general hospitals, psychiatric hospitals, and rehabilitation centers have begun applying horticulture as a means of treatment. Most of the research articles in Korea on various aspects of human issues in horticulture have been published since the foundation of two academic societies, the Korean Horticultural Therapy Association and the Korean Society for Plants, People, and Environment. These articles are primarily focused on the areas of school gardening, healing gardens, and psychological or physiological effects of horticultural activities. For the future development of human issues in horticulture in Korea, several areas need to be enhanced including: interdisciplinary studies of horticulture and social education; development of different skills, techniques,and scales to validate the effects of horticultural therapy, healing gardens, and gardening as a teaching tool in public education; and an organization empowered to certify horticultural therapists.
Efficacy of Plant Growth Retardants as Preplant Bulb Dips for Height Control in LA and Oriental Hybrid Lilies
Authors: Ranwala Anil P. , Legnani Garry , Reitmeier Mary , Stewart Barbara B. , Miller William B.
Published: December 2018

We evaluated preplant bulb dips in three commercial plant growth retardants [ancymidol (A-Rest), paclobutrazol (Bonzi), and uniconazole (Sumagic)] for height control in seven oriental hybrid lily (Lilium) cultivars (Aubade, Berlin, Casa Blanca, Muscadet, Sissi, Star Gazer, and Tom Pouce), and seven LA-hybrid lily [hybrids resulting from crosses between easter lily (Lilium longiflorum) and Asiatic hybrids] cultivars (Aladdin's Dazzle, Best Seller, Cebeco Dazzle, Royal Dream, Royal Parade, Royal Perfume, and Salmon Classic) grown in containers. A 1-min dip into a range of concentrations of each product was used to determine the optimum concentrations for height control. The results indicate that bulb dips, especially with uniconazole and paclobutrazol, can be a highly effective means of height control in hybrid lilies. Cultivars varied in their response to growth retardant treatments. In general, LA-hybrid lilies were much more responsive to the growth retardant treatments than oriental hybrids and required lower rates for comparable height control. Delays in flowering, increased bud abortion and leaf yellowing were observed only with high concentrations of uniconazole or paclobutrazol where the height reduction was also too excessive for a commercially acceptable crop.
In-row Spacing Influences Triploid Watermelon Yield and Crop Value
Authors: Motsenbocker Carl E. , Arancibia Ramon A.
Published: December 2018

Triploid watermelon (Citrullus lanatus), commonly called seedless watermelon, is increasing in popularity and market share. The optimum in-row spacing of triploid watermelon has not been studied previously. Triploid watermelon `Crimson Jewel' and `Honeyheart' were grown with drip-irrigation and black plastic mulch at 1-, 2-, 4-, 6-, and 8-ft (0.3-, 0.6-, 1.2-, 1.8-, and 2.4-m) in-row spacings in 1996 and 2-, 3-, 4-, 5-, 6-, 7-, and 8-ft. (0.6-, 0.9-, 1.2-, 1.5-, 1.8-, 2.1-, and 2.4-m) spacings in 1997 to determine the effect of in-row plant spacing on fruit yield. Marketable yield of `Crimson Jewel' was not affected by in-row spacing while narrower in-row spacing resulted in greater `Honeyheart' yield both years. For both cultivars, narrower spacing resulted in the highest number of fruit per acre, but primarily more extrasmall and small fruit. Fruit number per plant, fruit weight per plant, and individual fruit weight were higher at wider spacings, and yield per acre was lower. The data suggest that triploid watermelon yield, fruit weight and number can be adjusted by in-row spacing. Narrower in-row spacing can maximize yields, depending on the specific grower's cultural practices. In wider in-row spacings, the yield of medium and large fruit is maintained with a subsequent decrease in extra small and small fruit. Gross returns per acre were only different for farmers' market prices, not wholesale, and net returns were not significantly influenced by in-row spacing.
Efficacy of Using In-carton Fumigation with the Quarantine Treatment Against Codling Moth on Apples Intended for Export to Japan
Authors: Hansen James D. , Albano Dennis J. , Heidt Millie L.
Published: December 2018

The two-component quarantine treatment was shown to be effective against at least 7,000 codling moth (Cydia pomonella) fifth instar larvae infesting `Fuji' apples (Malus × domestica) in each required confirmation test involving two sizes of cartons. After cold storage for 55 days at 36 °F (2.2 °C), infested fruit were placed in vented cartons, either 20-lb [7 × 12 × 12.5 inches (17.8 × 30.5 × 31.8 cm)], or 40-lb [12 × 12.5 × 20.5 inches (30.5 × 31.8 × 52.1 cm)], then fumigated with 0.056 oz/ft3 (56 g·m-3) of methyl bromide for 2 hours at 50 °F (10.0 °C). After each treatment, either no survivors were present or no moribund larvae survived beyond the first week of post evaluation of the larvae.
Flatbed Scanners: An Alternative Tool for Gathering Horticultural Data
Authors: Kleeberger Kristin S. , Moser Bruno C.
Published: December 2018

Royal Horticulture Society Colour Chart cards were used to compare the Linotype-Hell Saphir color flatbed scanner, the Minolta CR-200 chromameter and the HunterLab Labscan XE colorimeter in the Commission Internationale de l'Eclairage L*a*b* three-dimensional color space. Regression analysis revealed that these instruments measure color in a similar manner with most R2 values greater than 0.97 and slopes near unity for comparison of each of the three color space parameters (L*, a*, b*). Standard errors were also found to be within a narrow range for each parameter, L* (2.19 to 3.97), a* (5.97 to 12.01), b* (4.10 to 6.71). The Linotype-Hell Saphir color flatbed scanner and the Minolta CR-200 chromameter were also compared for samples with surface curvature using redtwig dogwood (Cornus serecia 'Baileyi') and yellowtwig dogwood (Cornus serecia `Flaviramea') stems but no significant difference was found.
Design and Construction of the Penn State High Tunnel
Authors: Lamont William J. , McGann Martin R. , Orzolek Michael D. , Mbugua Nymbura , Dye Bruce , Reese Dayton
Published: December 2018

Plasticulture technology, especially high tunnels for extending the production period of a wide variety of horticultural crops, is an accepted production practice worldwide. In particular, high tunnels offer a production system that minimizes the effect of the environment on crop production and allows growers to continue to farm in densely populated areas. Only recently has the use of high tunnels in the U.S. been investigated and this research has been centered in the northeastern U.S. In 1999 the High Tunnel Research and Education Facility was established at Pennsylvania State University that resulted in the development of a unique high tunnel design. A detailed description of the new design and construction is presented in this report.
Pesticide Spraying in Indian River Grapefruit: I. Survey of Current Practices
Authors: Stover Ed , Scotto Dominick , Salvatore James
Published: December 2018

Pesticide spray practices for citrus (Citrus spp.) in the Indian River region of Florida were surveyed in 2001 as the first step in identifying opportunities for improving efficiency and reducing potential environmental impact. The survey covered 73% of grapefruit (C. paradisi) acreage in Indian River, St. Lucie, Martin and Palm Beach counties, comprising 70% of all Indian River commercial grapefruit. Large differences in spray practices were revealed. The focus of this survey was grapefruit spraying, since grapefruit represent 59% of fresh citrus shipped from the Indian River region, and are sprayed more intensively than citrus fruit grown for processing. In commercial groves, almost all foliar sprays to grapefruit are applied using air-assisted sprayers pulled through the groves by tractors. Use of engine-driven and power-takeoff-driven sprayers were reported with equal frequency and accounted for 89% of spray machines used. Lowvolume Curtec sprayers comprised the remainder. Spray volume for grape-fruit varied: 7.6% of acreage was sprayed at 25 to 35 gal/acre (230 to 330 L·ha-1) for all sprays; 4.2% was sprayed at 100 to 170 gal/acre (940 to 1600 L·ha-1) for all sprays; 15.3% was sprayed at 200 to 380 gal/acre (1900 to 3600 L·ha-1) for all sprays; 28.2% was sprayed at 450 to 750 gal/acre (4200 to 7000 L·ha-1) for all sprays; and 44.5% of grapefruit acreage was sprayed in a progressive manner from lower to higher volume as the season progresses. Many mid and high spray volume growers reported unacceptable results when they lowered spray volume. Although correlation was moderate (r = 0.35 to 0.45), regressions indicated that both total foliar pesticide spray material costs, and annual fungicidal copper (Cu) use increased with spray volume used for postbloom fungicides. Mean Cu use per acre was in the middle of the recommended range. All growers reported adjusting nozzling for tree height within a grove, and since Indian River groves are bedded, growers adjusted sprayer output differently for trees on bed tops versus furrows on 85% of acreage. Sprayers were shut off for missing trees on 83% of acreage, but this was done only for two or more adjacent trees on almost half of this area. Sensor-actuated sprayers were used to minimize off-target application on 14.7% of grapefruit acreage, but for an additional 21% of acreage, growers reported trying and abandoning this technology. While 88% of grove acreage was sprayed during the day, 75% of acreage sprayed using less than 100 gal/acre was sprayed at night. Growers reported no defined protocol for ceasing spray operations based on environmental conditions.
Evaluation of New Okra Cultivars for Bare Ground and Plasticulture Production
Authors: Simonne Eric , Hochmuth Bob , Simons Jeff , Vinson Edgar , Caylor Arnold
Published: December 2018

Several okra (Abelmoschus esculentus) cultivars are now available as alternatives to the standards `Clemson Spineless' (open pollinated) and `Annie Oakley II' (hybrid). Based on the results of four trials involving 20 cultivars, `Mita', `Spike', `Green Best' and `North & South' should be added to the list of recommended cultivars for Alabama and Florida. The experimental `SOK 601' should also be included on that list, but on a for trial basis since it was evaluated only at one location. Other cultivars may perform well at specific locations. Differences among cultivars were also found for ease of harvest. `North & South' and `Baby Bubba' were the easiest and most difficult cultivars to harvest, respectively. The economic feasability of selecting a hybrid cultivar over an open-pollinated one and using plasticulture instead of bare ground was also examined in this study. Using hybrid seeds resulted in an average yield increase per harvest of 92 lb/acre (103 kg·ha-1), which exceeded the estimated 75 lb/acre yield (84 kg·ha-1) increase necessary to offset the additional cost of hybrid seeds. For reasons ranging from improved weed control, increased nutrient and water use efficiency, and double cropping, an increasing interest exists to produce okra with plasticulture, instead of bare ground as done traditionally. The average yield increase per harvest due to plasticulture over bare ground production was 196 lb/acre (220 kg·ha-1). Based on this number, it would take three harvests to produce the 540 lb/acre (605 kg·ha-1) yield increase necessary to offset the additional costs due to plasticulture.
Distance Education versus Classroom Instruction in Horticulture—An Introduction to Fruit Crops—Case Study
Authors: Rieger Mark
Published: December 2018

At the University of Georgia, HORT 3020 (Introduction to Fruit Crops) is a two-credit survey of the botanical characteristics, taxonomy, and production practices of the world's major fruit crops. It is offered via traditional classroom instruction, and as a distance education (DE) course through the University System of Georgia Independent Study program. The DE version of the course is designed to be identical in content, final exam, and grading scale. However, due to the nature of independent study, the end-of-topic evaluations are open-book, written assignments in the DE course, whereas students in the classroom version have closed-book quizzes at the end of each topic. Student performance in the two versions of the course was compared over a 3-year period (May 1998 to May 2001) by analyzing scores on end-of-topic evaluations, final exams, and overall course grades. Students in the DE version had higher scores on end-of-topic evaluations in all 3 years, higher scores on a comprehensive final exam in 2 of 3 years, and consequently higher overall course grades than classroom students in all 3 years. Better performance of DE over classroom students may have been related to 1) qualitative differences in end-of-topic evaluations (written assignments versus quizzes), 2) differences in student demographics (nontraditional students in DE, traditional undergraduates in classroom), 3) the elective (DE) versus required (classroom) nature of the courses, or 4) differences in course duration (1 year for DE, 15 weeks for classroom). Equal or better performance of DE students suggests that survey courses such as Introduction to Fruit Crops can be offered via distance education without compromising learning outcomes.
Water Management Is Key in Reducing Nutrient Runoff from Container Nurseries
Authors: Bilderback Ted E.
Published: December 2018

Environmentally compatible production practices are conscious efforts to design and retrofit nursery container growing areas to improve irrigation and nutrient efficiency, and reduce exposure of ground and surface water supplies to contaminated effluent. Irrigation of ornamental crops in containers can be very inefficient, using large quantities of water and fertilizer. Irrigation water and fertilizer use efficiencies are directly related to each other. Improving irrigation efficiency improves nutrient efficiency and reduces water volume and nutrients leaving production beds. Increasing efficiency can be accomplished in many ways. Grouping plant species and container sizes into blocks with similar water requirements improves efficiency. Redesigning overhead sprinkler systems to accomplish uniform distribution across growing beds or replacing worn nozzle orifices can significantly reduce application variability. Low volume/low pressure systems that distribute water directly into containers and apply less water in a specific amount of time compared to overhead sprinkler application, will conserve water. Applying irrigation in short cycles rather than long cycles improves wetting in substrates and conserves electrical energy, water and directly reduces nutrient leaching from containers. Creating microclimates in nurseries to optimize light or reduce container temperatures, disease pressure and crop stress can improve water and nutrient efficacy. Flow of water running off growing areas must be engineered to slow velocity, filter and contain effluent. Strategies should be site-specific. Capture, containment and recycling of irrigation water has been a common practice in many nurseries in the U.S., as a means to provide adequate water supplies. Vegetative filter strips adjacent to beds and containment basins have been installed at nurseries to reduce contaminants in runoff before water enters recycle irrigation supplies. In areas with sandy soils, some nurseries have developed closed systems where drainage channels and collection basins are lined to prevent nitrogen movement from runoff into shallow groundwater.
Recent Advances in Strawberry Plug Transplant Technology
Authors: Durner Edward F. , Poling E. Barclay , Maas John L.
Published: December 2018

Plugs are rapidly replacing fresh-dug bare-root and cold-stored frigo plants as transplants for strawberry (Fragaria × ananassa) production worldwide. Plugs have many advantages over these other types of propagules. They are grown in controlled environments (greenhouses, tunnels) in less time than field produced bare-root transplants, and are not exposed to soilborne pathogens. Plugs afford greater grower control of transplanting dates, provide mechanical transplanting opportunities and allow improved water management for transplant establishment relative to fresh bare-root plants. New uses for plugs have been identified in recent years; for example, photoperiod and temperature conditioned plugs flower and fruit earlier than traditional transplants and plugs have been used for programmed greenhouse production. Tray plants have superior cold storage characteristics relative to bare-root, waiting-bed transplants. Both fresh and frozen plugs are used in a number of indoor and outdoor growing conditions and cultural systems.
Is Vegetable Variety Evaluation and Reporting Becoming A Lost Art? An Industry Perspective
Authors: Williams Tom V. , Roberts Warren
Published: December 2018

Is there a more important component to a grower's production practices than the choice of the best variety to plant? Probably not, yet there is less public vegetable variety testing than ever before, despite the increasing introduction of new varieties by the seed industry. This article examines the reasons for fewer vegetable variety trials, discusses the benefits of good variety reporting, and considers the keys to conducting a successful vegetable variety trial. Vegetable variety performance could be interpreted best on a regional basis if a standard format for evaluating each species is developed. One such attempt at standardizing watermelon (Citrullus lanatus) evaluation is presented. Finally, several recent vegetable trial reports are discussed to point out the difference of each and what additional data could have been provided.
Vegetable Variety Trials: An Administrative Point of View
Authors: Cantliffe Daniel J.
Published: December 2018

Since the establishment of the land-grant systems in the late 1800s, universities and experiment station systems have sought out and tested vegetable germplasm for its suitability in regional and local areas across the United States. The private seed industry continued to grow, both in number and volume of sales through the early half of the twentieth century. It was during this time that many of the public breeding programs at land-grant universities began corollary plant breeding programs in variety development for vegetables. For many years it was a cooperative coexistence between the private seed industry and the public programs, wherein the seed industry derived much of its germplasm for new variety releases from the public sector. Beginning in the 1970s, the numbers of public breeders began to decline, while the numbers, especially of PhD plant breeders in the private sector, began to proliferate. Throughout this 100-year period university personnel were actively involved in vegetable variety trials, both on main campuses as well as at experiment stations, and in many cases in locales in various counties through cooperative efforts with county agents. Up through this period much credit could be given to individual faculty members for their involvement in such endeavors. In the past 10 to 20 years, many things have changed in university operations and perspectives, namely faculty are only given credit for refereed publications, regardless of the area in which they work. Moreover, they must constantly procure money to support their programs. In the past, vegetable variety testing generally did not lead to refereed publications and was not supported by the industry. Moreover, as previously mentioned many of the public programs in germplasm improvement for vegetables across the United States have ceased, thus ending a direct need for variety testing to support these programs. The critical issue for today's faculty is the relative importance of variety testing and delivering information to the general public versus how they would support such a program and eventually get academic credit for conducting such a program.
Going Organic Changes Weed Population Dynamics
Authors: Ngouajio Mathieu , McGiffen Milton E.
Published: December 2018

Organic agriculture is growing in importance worldwide. In the United States, the rate of increase of organic growers was estimated at 12% in 2000. However, many producers are reluctant to undertake the organic transition because of uncertainty of how organic production will affect weed population dynamics and management. The organic transition has a profound impact on the agroecosystem. Changes in soil physical and chemical properties during the transition often impact indirectly insect, disease, and weed dynamics. Greater weed species richness is usually found in organic farms but total weed density and biomass are often smaller under the organic system compared with the conventional system. The improved weed suppression of organic agriculture is probably the result of combined effects of several factors including weed seed predation by soil microorganisms, seedling predation by phytophagus insects, and the physical and allelopathic effects of cover crops.
Nematode and Insect Management in Transitional Agricultural Systems
Authors: McSorley R.
Published: December 2018

As an agroecosystem makes the transition from conventional to organic practices, changes in the pest management tactics used are often apparent. Despite varying degrees of efficacy among tactics, the issue of whether or not numbers of insect and nematode pests and their damage will become more severe in an organic system depends on the specifics of the pests and crops involved. Although many conventional systems rely on reactive strategies to deal with pest problems, an alternative approach is to redesign systems so that plant health is maximized, regardless of pest numbers, although this approach takes planning and time. An abrupt transition from conventional to organic may be risky if pest numbers are high and alternative practices are not yet in place. Hybrid systems, involving decreasing levels of conventional tactics and increasing levels of organic tactics, may be needed before the transitional period begins, in order to bridge the gap and lessen the impact of crop losses during the transitional period. The design of cropping systems with minimal pest impact requires a much more extensive and specific knowledge base than needed for reactive strategies.
Transition from Conventional to Organic Farming Systems: II. Summary of Discussion Session and Recommendations for Future Research
Authors: Zinati Gladis M.
Published: December 2018

A question/answer discussion session was conducted at the conclusion of the workshop “Pest Management During Transition to Organic Farming Systems”. The following categories were used to summarize the discussion: 1) questions and answers related to cultural and biological practices and their effects under various climatic conditions, 2) recommendations for pest management, and 3) future research needs. While many tactics are available, selecting and adopting the most suitable approach depends on soil conditions of the land, location, and the availability of the resources at affordable prices. Definitely, more research studies are needed on 1) weed seed banks under various cultural practices at different regions, 2) relationships between soil nutrients, and pest control, and 3) approaches to increase profitability of organic production during the transition period.
Flutolanil for Control of Necrotic Fairy Rings on Bermudagrass Putting Greens
Authors: Elliott Monica L. , Hickman Robert B. , Hopkins Mark
Published: December 2018

Type 1 (necrotic) fairy rings in turfgrass result in dead or badly damaged grass. This type of fairy ring is a severe problem on golf course greens as they interfere with the aesthetics and playability of the putting surface. In Florida, Lycoperdon spp., basidiomycetes that produce puffball mushrooms, have been implicated as a common cause of Type 1 fairy rings on hybrid bermudagrass (Cynodon dactylon × C. transvaalensis) putting greens. The fungicide flutolanil has basidiomycetes as the sole fungal target. It is also the only carboxin-related fungicide registered for use on turfgrass. Two experiments were conducted to examine the effect of flutolanil as a curative and preventive treatment for fairy ring caused by Lycoperdon. One experiment, established after the rings were present, determined that flutolanil significantly reduced mushroom production. The second experiment was conducted on a golf course that had experienced Type 1 fairy rings previously. One-half of each of nine putting greens was treated with flutolanil on a preventive basis. The other half of each green served as an untreated control. Type 1 fairy rings, due to Lycoperdon, developed only on the untreated control half of each green. These experiments confirm that flutolanil does have curative and preventive activity against Lycoperdon spp. that cause Type 1 fairy rings.
A Comparison of Temperate-climate Strawberry Production Systems Using Eastern Genotypes
Authors: Black Brent L. , Enns John M. , Hokanson Stan C.
Published: December 2018

Anticipating the phaseout of methyl bromide, the USDA-ARS small fruit breeding program at Beltsville, Md., discontinued soil fumigation in strawberry breeding and selection trials in the mid 1990s. To address resulting weed and pathogen pests, a modified or advanced matted row system was developed. This system uses matted row-type culture, established on raised beds with subsurface drip irrigation and organic mulch. The mulch is the residue of a killed cover crop that fixes some nitrogen and provides an economical, biodegradable mulch for suppressing weeds and reducing erosion. Since 1996, the small fruit breeding program has conducted replicated performance trials on both advanced matted row and a regional adaptation of annual hill plasticulture. Both of these systems were managed without methyl bromide fumigation or fungicide application. Data from these trials were used to compare advanced matted row and plasticulture for yield, fruit quality and harvest season. Yield for the two systems was genotype dependent, and the advanced matted row system had later production and slightly lower fruit quality.
Influence of Bed Cover Types on Production Time and Quality of Sweetpotato Slips
Authors: Beaulieu John C. , Marsh Dyremple B.
Published: December 2018

Sweetpotato (Ipomoea batatas) cultivars, Carver, Potojam, Jewel and Centennial were evaluated for slip production, using topsoil, sawdust, sand and a general-purpose peat-based commercial growing media as bed covers. Temperature measured 2 inches (5.1 cm) below the surface of the hot bed varied with covers and date measured. Sand maintained the highest bed temperature, 77 °F (25.0 °C) at 0800 hr and 79 °F (26.1 °C) at 1400 hr, throughout the growing season. Peat-covered roots produced the maximum number of slips/plot (111), while roots covered with topsoil and sawdust produced comparable yields, 55 and 45 slips/plot, respectively. Slip production varied according to harvest date, with the third harvest producing the most slips/plot (83 and 153, in year 1 and year 2, respectively), which, was likely related to increased temperatures. Cultivar significantly influenced number of slips, length of slips, and number of roots per slip. `Potojam' was the most prolific slip producer for both early and mid season production under all bed covers.
Greenhouse Growth of Marigolds in Three Leached Sources of Spent Mushroom Compost over a 3-Year Period
Authors: Young John R. , Holcomb E. Jay , Heuser Charles W.
Published: December 2018

Though high electrical conductivity (EC) levels are commonly held to be the primary limiting factor for using spent mushroom compost (SMC) as a growing substrate, EC can be reduced by leaching. This allowed SMC to be successfully used for growing plants. Leaching reduced EC of the substrate solution from as high of 30 dS·m-1 (mmhos·cm-1) to 2 to 3 dS·m-1, a level acceptable for growing plants. The initial EC and container capacity determined the number of leachings and total volume of water required to lower EC of SMC substrates to acceptable levels. As the concentration of SMC was increased, a higher number of leachings or larger volume of water were required to adequately reduce EC levels. In trials spanning 2.5 years, SMC was effectively used as a substrate in the production of marigold (Tagetes patula) `Yellow Girl'. Benefits to plant growth from SMC incorporation included a slow release of nutrients as the SMC decomposed and a good air-filled pore space/water-holding capacity when amended with a commercial nursery mix. From these trials, it is recommended that SMC be incorporated at rates of 25% to 50%. It is not recommended that SMC be used in concentrations over 50% because the EC may be too difficult to manage and the high levels of air-filled pore space of SMC. Though season may affect the initial EC level of SMC, such variation is minimized by leaching while differences in plant response are more likely to be attributed to environmental conditions. No differences in plant growth were observed among SMC sources.
Penn State High Tunnel Extension Program
Authors: Lamont William J. , Orzolek Michael D. , Holcomb E. Jay , Crassweller Robert M. , Demchak Kathy , Burkhart Eric , White Lisa , Dye Bruce
Published: December 2018

The Center for Plasticulture's High Tunnel Research and Education Facility was established at Pennsylvania State University in 1999. Since its inception, applied research has been conducted at this facility by a team of researchers and extension specialists on the development of a new high tunnel design. The development of crop production recommendations for vegetables, small fruits, tree fruits and cut flowers grown in high tunnels has been a priority. To complement the applied research program, an aggressive extension education program was developed to extend information on the technology of high tunnels to county extension personnel, growers, industry representatives, students, master gardeners and the general public. The extension programming effort consisting of demonstration high tunnels, field days, tours, in-service training, publications and presentations made at winter meetings will be discussed in the report below.
Using Web-based Distance Learning Methods to Teach Nutrient Management Planners
Authors: Lea-Cox John D. , Varley Ellen N. , Ross David S. , Teffeau K. Marc
Published: December 2018

The State of Maryland Legislature enacted the Water Quality Improvement Act in 1998, which requires all agricultural operations to develop and implement nitrogen- and phosphorus-based nutrient management plans by December 2002. This legislation also mandates the education and training of professionals who will write nutrient management plans, and growers who will implement them. Maryland Cooperative Extension faculty have therefore been charged with developing effective educational programs that will enable nursery and greenhouse industry professionals to achieve these goals and ensure industry compliance with this legislation.
Weed Control in Field Nurseries
Authors: Altland James E. , Gilliam Charles H. , Wehtje Glenn
Published: December 2018

Herbicide use is an important component of weed management in field nursery crops. No single herbicide controls all weed species. Oxyfluorfen, simazine, and isoxaben are preemergence herbicides effective against broadleaf weeds. Oryzalin, pendimethalin, and prodiamine are effective in preemergence control of grasses and some small-seeded broadleaf weeds. Metolachlor is the only herbicide currently labeled for nursery crops that is effective in preemergence nutsedge (Cyperus) control. Fluazifop-butyl, sethoxydim, and clethodim are selective postemergence herbicides used for grass control. Glyphosate, paraquat, and glufosinate are nonselective postemergence herbicides used in directed spray applications for broad-spectrum weed control. Bentazon, halosulfuron, and imazaquin are effective postemergence nutsedge herbicides. These herbicides are discussed with respect to their chemical class, mode of action, labeled rates, and current research addressing their effectiveness in nursery crops.
Novel Methods of Weed Control in Containers
Authors: Mathers Hannah M.
Published: December 2018

Nursery growers estimate that they spend $500 to $4000/acre ($1235 to $9880/ha) of containers for manual removal of weeds, depending upon weed species being removed. Economic losses due to weed infestations have been estimated at about $7000/acre ($17,290/ha). Herbicide treated bark nuggets were found extremely effective for weed control in studies during 1998, regardless of whether oxyfluorfen, oryzalin, or isoxaben were applied to the bark. A study conducted in 2000 compared 24 treatments of novel nonchemical alternatives, conventional chemical practices and herbicide treated barks. Four of the best treatments were herbicide treated douglas fir bark, specifically, small [<1 inch (2.5 cm) length] douglas fir nuggets treated with oryzalin at the 1× rate, large (>1 inch length) douglas fir nuggets treated with oryzalin at the 0.5× rate, small douglas fir nuggets treated with oryzalin at the 0.5× rate and large douglas fir nuggets treated with flumioxazin at the 1× rate. The four bark treatments indicated above provided equivalent efficacy and phytotoxicity to Geodiscs. Penn Mulch and Wulpack provided poor weed control. Mori Weed Bag, a black polyethylene sleeve, and Enviro LIDs, a plastic lid provided less control than herbicide treated bark. Compared to the bark alone, herbicide treated bark provides a 1.8-fold increase in efficacy and a 2.8-fold extension in duration of efficacy. Compared to the herbicide alone, herbicide treated bark provides a 1.5-fold increase in efficacy and a 2.2-fold reduction in phytotoxicity. Of the innovative weed control products tested herbicide treated bark provided the most promising results. The data support that the bark nuggets are possibly acting as slow release carriers for the herbicides or reducing the leaching potential of the herbicides. Recent studies have indicated that the controlled release of herbicides using lignin as the matrix offers a promising alternative technology for weed control.
Controlling Liverwort and Moss Now and in the Future
Authors: Fausey Jason C.
Published: December 2018

The liverwort, marchantia (Marchantia polymorpha), and silver thread moss (Bryum argenteum) are two highly invasive and difficult to control pests in containerized ornamentals. Container trials were conducted evaluating marchantia and silve r thread moss control with preemergence and postemergence applications of chlorothalonil, captan, ammonium chlorides, hydrogen dioxide, flumioxazin, oxyfluorfen, pelargonic acid, acetic acid (vinegar), copper sulfate, cinnamaldehyde, prodiamine, and oxadiazon. Flumioxazin, oxyfluorfen, pelargonic acid, acetic acid, and oxadiazon provided acceptable preemergence and/or postemergence marchantia and silver thread moss control; however, no product provided acceptable control of these weeds at all evaluations. Under controlled environmental conditions marchantia and silver thread moss were controlled with flumioxazin, oxyfluorfen, pelargonic acid, acetic acid, and oxadiazon. In addition to providing postemergence control of these weeds, flumioxazin, oxyfluorfen, and oxidiazon also had residual activity when applied to potting media. However, the length and effectiveness of the preemergence control with flumioxazin, oxyfluorfen, and oxadiazon was dependant upon formulation. In a separate study comparing granular and sprayable formulations of flumioxazin, oxyfluorfen, and oxidiazon, results indicated control of established marchantia and silver thread moss was greater with sprayable formulations when compared with granular formulations. Similarly, sprayable formulations of these active ingredients enhanced residual marchantia and silver thread moss control. The granular and sprayable formulations of flumioxazin provided greater preemergence and postemergence control of marchantia and silver thread moss when compared with granular or sprayable formulations of oxyfluorfen and oxadiazon, and of the products evaluated, displayed the greatest level of activity against these weeds.
California Crop Improvement Association Disease Inspection Program: Production Practices for Clean Seed
Authors: Sundstrom F.J. , Guzman P. , Stewart R.F.
Published: December 2018

Pathogen free seed has long played a critical role in reducing or eliminating the severity of various diseases in commercial fields. The California Crop Improvement Association (CCIA) provides quality assurance services to the seed industry that are designed to promote the production, distribution and use of high quality seedstocks for agricultural production. To that end, CCIA has developed a Disease Inspection Program to assist vegetable seed producers in eliminating the bacterium, Acidovorax avenae subsp. citrulli (AAC), from cucurbit (Cucurbitaceae) seedstocks. This program utilizes recommendations and standards beginning at parent seed production of hybrids through the production of commercial seedlots. Training of field personnel, field inspections and tissue tests, followed by growouts of at least 30,000 seedlings are used as components of this quality assurance program.
Prevention and Management of Diseases on Vegetable Transplants
Authors: Greathead Arthur S.
Published: December 2018

The use of disease-free greenhouse-grown plug transplants for the establishment of field plantings of many vegetable crops in the arid west and southwestern regions of the United States has become a very important part of the agricultural system in these areas. The development of effective disease-control programs for use in the greenhouse involves a broad knowledge of production systems, water management, growing media, cultural techniques, etc., as well as knowledge of the discipline of plant pathology. The consultant in this field also must know the people and organizations with whom he is working. His goal is not simply the passing on of technical information, but also assisting in the incorporation of that information into the total growing program. Good communication skills and the development of an atmosphere of trust between all parties concerned are a vital part of the consultant's work.
Influence of Diploid Pollinizer Frequencies on Triploid Watermelon Quality and Yields
Authors: Fiacchino Dena C. , Walters S. Alan
Published: December 2018

During the 1999 and 2000 growing seasons in Illinois, studies were conducted to determine the influence of two pollinizers (`Crimson Sweet' and `Fiesta') and three pollinizer frequencies (11%, 20%, and 33%) on `Millionaire' seedless watermelon (Citrullus lanatus) quality and yields. More large-sized [>16 lb (7.2 kg)] `Millionaire' watermelons were produced when `Crimson Sweet' was used as the pollinizer compared to `Fiesta', which resulted in `Crimson Sweet' leading to greater marketable and total `Millionaire' yields. Pollinizers responded similarly over the pollinizer frequencies for `Millionaire' watermelon yields as no pollinizer by pollinizer frequency interaction was observed. The 20% and 33% pollinizer frequencies produced similar `Millionaire' yields per acre and both resulted in greater yields compared to the 11% pollinizer frequency. Soluble solids in `Millionaire' fruits were not influenced by pollinizer or pollinizer frequency. However, hollow heart disorder followed a quadratic response with respect to pollinizer frequency with the lowest amount of hollow heart observed at the 33% pollinizer frequency and greatest at the 11% pollinizer frequency. No significant interaction (P ≤ 0.05) was observed for pollinizer by pollinizer frequency for hollow heart disorder in `Millionaire'; although, more hollow heart disorder in `Millionaire' was observed when `Fiesta' was used as the pollinizer.
Mycorrhizal Fungi in Rooting Substrate Influences the Quantity and Quality of Roots on Stem Cuttings of Hick's Yew
Authors: Scagel C.F. , Reddy K. , Armstrong J.M.
Published: December 2018

In a commercial nursery propagation system for hick's yew (Taxu×media `Hicksii'), we assessed whether or not the addition of inoculum of the vesicular-arbuscular mycorrhizal fungus (VAMF) Glomus intraradices into the rooting substrate during cutting propagation increased rooting, and how the quantity of inoculum influenced rooting. At 15 and 22 weeks (108 and 156 d) after cuttings were treated with root hormones and stuck, root initiation was higher on cuttings stuck in the rooting substrate containing VAMF inoculum. Increasing the quantity of inoculum in the rooting substrate increased root growth during the early stages of rooting. However the highest level of inoculum tested increased adventitious root initiation without increased root growth. Our results indicate that if VAMF inoculum is used during propagation from cuttings, there are optimal levels required to alter the initiation and growth of roots. For hick's yew, 1:100 or 2:100 (by volume) rates of G. intraradices in the rooting substrate increased the number of primary roots and growth of adventitious roots on cuttings above that achieved by using rooting hormone alone.
Effects of Intermittent Warming and Temperature Conditioning on the Postharvest Quality of `Oroblanco' Citrus Fruit Following Long-term Cold Storage
Authors: Porat R. , Weiss B. , Cohen L. , Daus A. , Cohen E.
Published: December 2018

`Oroblanco' is an early-maturing pummelo-grapefruit hybrid (Citrus grandis × C. paradisi). The fruit of this cultivar are usually picked in October and are marketed while their peel color is still green. However, during long-term storage, the fruit turns yellow, and loses much of their commercial value. In a previous study, we found that application of gibberellic acid and low storage temperatures of 2 °C (35.6 °F) markedly reduced the rate of degreening. However, `Oroblanco' fruit are sensitive to chilling injuries, and thus could not be stored at 2 °C for long periods. In the present study, we examined the possible application of intermittent warming (IW) and temperature conditioning (TC) treatments, in order to retain the green fruit color during long-term cold storage but without enhancing the development of chilling injuries. It was found, that following storage at 2 °C, either with or without IW and TC, the fruit retained green color up to 16 weeks, whereas at 11 °C (51.8 °F) fruit turned yellow after 8 weeks. However, untreated fruit held continuously at 2 °C developed 40, 51, and 68% chilling injuries after 8, 12, and 16 weeks, respectively. IW (storage at cycles of 3 weeks at 2 °C + 1 week at 11 °C) reduced the amount of chilling injuries to only 5, 7 and 11% after the same periods of time, respectively. TC [a pre-storage treatment for 7 days at 16 °C (60.8 °F) before continuous storage at 2 °C] effectively reduced the development of chilling injuries to only 5% after 8 weeks of storage, but was ineffective in reducing chilling damage after longer storage periods. Because chilling damaged fruit is prone to decay, the IW and TC treatments also reduced the incidence of decay development during storage. The IW and TC treatments did not affect juice total soluble solids and acid percentages, but did affect fruit taste and the amounts of off-flavor volatiles emitted from the juice. Taste panels indicated that the taste score of untreated control fruit stored at 11 °C gradually decreased during long-term storage, and that this decrease was more severe in chilling damaged fruit stored continuously at 2 °C. The taste of IW-treated fruit remained acceptable even after 16 weeks of storage, and TC-treated fruit remained acceptable for up to 12 weeks. Fruit taste scores were inversely correlated with the concentrations of ethanol and acetaldehyde detected in the juice headspace.