bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrient Management in Organic Greenhouse Herb Production: Where Are We Now?
Authors: Treadwell Danielle D. , Hochmuth George J. , Hochmuth Robert C. , Simonne Eric H. , Davis Lei L. , Laughlin Wanda L. , Li Yuncong , Olczyk Teresa , Sprenkel Richard K. , Osborne Lance S.
Published: December 2018

Consumer demand for fresh market organic produce combined with the increasing market share of ready-to-eat products indicates the potential for expansion of an organic culinary herb market. Barriers to organic herb greenhouse production are high as a result of lack of available technical information and the low number of producers experienced in this area. There is a critical need for information and technologies to improve the management of organic soil and fertilizer amendments to optimize crop yields and quality, manage production costs, and minimize the risk from groundwater nitrogen (N) contamination. Because of limited information specific to organic culinary herb production, literature on organic vegetable transplants and conventional basil (Ocimum basilicum) production was also considered in this review. Managing N for organic crops is problematic as a result of the challenge of synchronizing mineralization from organic fertilizer sources with crop N demand. A combination of materials, including locally formulated composts, supplemented with standardized commercially formulated fertilizer products is one method to ensure crops have access to mineral N throughout their development. In experimental greenhouse systems, local raw materials are frequently used as media amendments to satisfy partial or complete crop fertility requirements. This makes comparisons among experiments difficult as a result of the wide variety of raw materials used and the frequent interactions of fertilizer source and planting media on nutrient availability. Nitrogen mineralization rates are also influenced by additional factors such as the environmental conditions in the greenhouse and physical and chemical properties of the media and fertilizer. Despite the variability within and among experimental trials, yields and quality of organically grown crops are frequently similar to, and occasionally better than, conventionally grown crops.
Germination Characteristics of Three Warm-season Turfgrasses Subjected to Matriconditioning and Aging
Authors: Hacisalihoglu Gokhan
Published: December 2018

Many warm-season turfgrass seeds have relatively poor germination percentages. Matriconditioning is a seed enhancement technique with a solid carrier and may be a practical solution to improve the germination characteristics of warm-season turfgrass. The objective of this study was to determine the effectiveness of matriconditioning on three nonaged and aged turfgrass cultivars: ‘Pensacola’ bahiagrass (Paspalum notatum), ‘Princess’ bermudagrass (Cynodon dactylon), and ‘Common’ centipedegrass (Eremochloa ophiuroides). Seeds were matriconditioned with a synthetic calcium silicate (MicroCel E) as a carrier and water at 30 °C for 5 days. Seed, carrier, and water ratio was 1 g, 0.5 g, and 1.5 mL, respectively. Matriconditioning increased final germination to 55% (bahiagrass), 90% (bermudagrass), and 70% (centipedegrass) compared with 92% in nontreated control seeds. Furthermore, matriconditioning decreased mean germination time 20% to 65% in all seeds compared with the nontreated control. Accelerated aging was induced by storing seeds for 0, 7, and 14 days at 42 °C and 95% relative humidity. Germination percentage decreased and mean germination time increased with the aging, especially after 14 days of aging treatment. These results suggest that matriconditioning is an effective technique to improve turfgrass seed performance.
Pre-transplant Root Ball Condition Influences Growth of Plumbago During Establishment
Authors: Vyapari Sudeep , Scheiber S.M. , Thralls E.L.
Published: December 2018

Three root ball conditions—nonroot-bound (NRB), root-bound (RB), and root-bound sliced (RBS)—were evaluated for their effect on plant growth of plumbago (Plumbago auriculata) during establishment and postestablishment in the landscape. At transplant, NRB plants were smaller than other treatments. Canopy size, shoot dry weight, root dry weight, and total biomass growth rates were faster for NRB plants compared with RB or RBS. By 6 and 8 weeks after transplanting, respectively, biomass and canopy size were similar among treatments. Rootbound and RBS plants were similar indicating root ball slicing does not affect growth in the landscape.
Effect of Nitrogen Fertigation on First-year Pecan Seedling Growth
Authors: Conner Patrick
Published: December 2018

Pecan (Carya illinoinensis) seedling rootstocks require several years of growth in the nursery before they are large enough to graft. In this experiment, first-year pecan seedlings were fertigated with varying amounts of calcium nitrate in an attempt to stimulate growth rates. Pecan seedlings were fertigated every 2 weeks from May through October for a total of 10 applications. Total amounts of nitrogen (N) applied by fertigation were 0, 4, 10, 20, and 40 g of N per seedling. Leaf samples were taken after the fourth and tenth fertigations, and leaf elemental concentration was affected by fertigation rates. Seedling height and caliper were measured monthly. Seedling caliper continued to increase throughout the experiment, whereas height increase stopped in September. Seedling height and caliper were unaffected by N fertigation except for the N rate of 40 g, which suppressed seedling growth. These results suggest that the N needs of the seedlings were met by a preplant application of 50 lb/acre N applied as 10N–4.4P–8.3K.
A Survey of the Ornamental Horticulture Industry in Iowa
Authors: Haynes Cynthia , VanDerZanden Ann Marie , Iles Jeffery K.
Published: December 2018

The ornamental horticulture industry in the United States (the green industry) is a multibillion dollar industry that contributes to the economy of every state. Greenhouse and nursery products rank in the top 10 commodities produced in 42 states. In 2004, a 38-question survey was developed and mailed to 1281 members of Iowa's green industry, including wholesale and retail greenhouses, nurseries and florists, garden centers, landscape designers and contractors, and arborists, to gather information on the scope, scale, and business climate of the green industry in Iowa. All business types were represented in the 117 usable surveys that were returned. Although size and type of businesses varied, a majority of respondents had only one location, were family-owned, and had been in business less than 6 years. Respondents reported few factors that could limit their business success, and most felt they were much stronger than their competitors in the areas of customer perception of product quality and service and ability to meet customer needs. The estimated value of sales and services directly related to Iowa's green industry in 2004 was $311.5 million, and a majority of respondents expected their business to grow in the areas of employment, annual gross payroll and sales, and total annual expenses by 2010.
Diploid Watermelon Pollenizer Cultivars Differ with Respect to Triploid Watermelon Yield
Authors: Freeman Joshua H. , Miller G.A. , Olson S.M. , Stall W.M.
Published: December 2018

As triploid watermelons (Citrullus lanatus) increase in popularity, production has shifted away from seeded watermelons. To achieve successful fruit set in triploid watermelons, a diploid watermelon cultivar must be planted as a pollen source. Three diploid cultivars in 2005 and seven diploid cultivars in 2006 were evaluated at one and three locations, respectively, to determine their effectiveness as pollenizers. Each cultivar was planted within plots of the triploid watermelons ‘Tri-X 313’ (2005) and ‘Supercrisp’ (2006) with buffers on all sides of the plots to contain pollen flow within individual plots. Performance of pollenizers was based on triploid watermelon yield, soluble solids concentration, and incidence of hollowheart. In 2005, there were no significant differences in total weight, fruit per acre, average weight, or soluble solids concentration among pollenizers. In 2006, significant differences in yield were observed, and plots with ‘Sidekick’ as a pollenizer yielded the highest but were not significantly different from ‘Patron’, ‘SP-1’, ‘Jenny’, or ‘Mickylee’. In 2006, there were no significant differences in fruit per acre, soluble solids concentration, or incidence of hollowheart between pollenizers. The experimental design was successful in isolating pollenizers and there was minimal pollen flow outside of experimental plots as indicated by minimal fruit set in control plots.
Using Open Source Software in Developing a Web-accessible Database of Sweetpotato Germplasm Collections in Kenya
Authors: Villordon Arthur , Njuguna Wambui , Gichuki Simon , Ndolo Philip , Labonte Don
Published: December 2018

Web-accessible germplasm databases allow stakeholders to interactively search and locate information in real time. These databases can also be configured to permit designated users to remotely add, delete, or update information. These resources assist in decision-making activities that are related to germplasm documentation, conservation, and management. We report the development of a web-accessible database of Kenyan sweetpotato (Ipomoea batatas) varieties using open source software. Kenya is located in eastern Africa, a region that is considered one of the centers of diversity for sweetpotato. We describe the software applications used in developing the germplasm database as well as the web interface for displaying and interactively searching records. This report demonstrates that open source software can be used in developing a web-enabled database with management features similar to those found in proprietary or commercial applications.
Influence of Plant Density on Yield and Fruit Quality of Greenhouse-grown Galia Muskmelons
Authors: Rodriguez Juan C. , Shaw Nicole L. , Cantliffe Daniel J.
Published: December 2018

Galia-type muskmelon (Cucumis melo cv. Gal-152) was grown as a fall and spring crop to determine the effect of plant density (1.7, 2.5, 3.3, and 4.1 plants/m2) on yield, fruit quality, plant growth, and economic feasibility for producing the crop in a greenhouse. Plant density had no influence on the early or total number of fruit produced per plant. Marketable yields increased linearly from 11.0 to 20.0 kg·m−2 in fall and from 21.9 to 48.3 kg·m−2 in spring with increasing plant density. Mean fruit size was unaffected by plant density during fall (mean weight, 1.0 kg), but was reduced linearly during spring from 1.8 kg at 1.7 plants/m2 to 1.5 kg at 4.1 plants/m2. Soluble solids content was unaffected by plant density in either fall or spring and averaged 10.1% in both seasons. Number of leaves per plant was unaffected by plant density, but internode length was increased at 4.1 plants/m2 compared with plants from the other densities. Increasing the plant density of ‘Gal-152’ muskmelon grown under protected cultivation led to increased yields in both fall and spring without negatively impacting fruit quality. When the market price is $1.44/kg, increased yields at 3.3 plants/m2 can potentially increase net returns over yields of plants spaced at 2.5 plants/m2 by 25% and nearly double net returns from plants grown at 1.7 plants/m2.
A Comparison of Fruit Quality and Consumer Preferences Among Three Cold-climate Strawberry Production Systems
Authors: Stevens Matthew D. , Lea-Cox John D. , Black Brent L. , Abbott Judith A.
Published: December 2018

In consumer-harvested marketing, crop management practices and production systems directly affect the experience of the customer. An experiment was designed to compare overall consumer preference and fruit quality characteristics among three perennial cold-climate strawberry (Fragaria ×ananassa) production systems: conventional matted row (CMR), advanced matted row (AMR), and cold-climate plasticulture (CCP). Replicate plots of each system were maintained for two harvest seasons. Volunteers harvested subplots in each system and completed a survey to evaluate pick-your-own consumer preferences. The CCP system was preferred by a majority of consumers in the first year, whereas the AMR system was rated highest in the second year. Preferences were positively correlated with ease of harvest and fruit appearance and negatively correlated with the percentage of fruit unfit for harvest. Fruit quality measurements made on marketable fruit in the second harvest season indicated that there were no treatment differences in titratable acidity or soluble solids concentration, but significantly lower fruit firmness in the CCP treatment compared with CMR and AMR.
Evaluation of Yardlong Bean as a Potential New Crop for Growers in the Southeastern United States
Authors: Coker Christine , Ely Mike , Freeman Thomas
Published: December 2018

Ethnicity plays a strong role in niche market development, and the Asian market is currently underserved. As Asian populations continue to grow in Mississippi, especially along the Gulf Coast, it is important to recognize new market opportunities. The fruit and vegetables desired by the diverse Asian population are often unavailable or of poor quality as a result of extensive shipping distances. Mississippi growers can meet this need for fresh Oriental produce at a higher price than traditional vegetables. Yardlong bean or asparagus bean (Vigna unguiculata ssp. sesquipedalis) is the same species as cowpea. The cultural practices for yardlong bean are similar to that of traditional pole beans (Phaseolus vulgaris). However, there is still much to be learned about this crop in terms of pest management, disease susceptibility, and varietal superiority. The objectives of this research were to compare length and yield of eight yardlong bean varieties and collect observational data regarding production practices. Four replications of eight yardlong bean varieties were grown at Beaumont, MS, during Summer 2001 and 2002. Beans were grown on 4-ft-wide trellises 1 ft above the soil line. Beans were harvested twice per week. Highest marketable yields were attained with the varieties Red Seed and Black Seed, which are best suited for growing conditions in southern Mississippi. However, mosaic viruses may pose a potential production problem, and further research is warranted to determine best cultural practices and pest management.
Viticultural Performance of Red and White Wine Grape Cultivars in Southwestern Idaho
Authors: Shellie Krista C.
Published: December 2018

A collection of 23 red and six white wine grape (Vitis vinifera) cultivars were evaluated for viticultural performance in Parma, ID. Vine yield, fruit composition, and vegetative growth were measured over four growing seasons, and data were used to compare relative cultivar performance based on yield to pruning ratio and fruit maturity. Relative differences among cultivars in budbreak day of year [96 (6 Apr.) to 122 (2 May)] and days from budbreak to harvest (143 to 179 days) varied from year to year. The earliest and latest maturing cultivars in 3 of 4 years were ‘Blauer Portugieser’ (143 days), ‘Nebbiolo’ (177 days), ‘Barbera’ (179 days), ‘Orange Muscat’ (144 days), ‘Flora’ (149 days), ‘Muscat of Alexandria’ (166 days), and ‘Viognier’ (168 days). Cultivars differed in yield (2.4 to 7.0 tons/acre), vegetative vigor (4.6 to 20.4 yield/pruning weight), and harvest soluble solids concentration (21.1 to 26.5), but differences in harvest pH (3.0 to 4.1) and titratable acidity (2.48 to 13.03 g·L−1) varied from year to year. Average heat unit accumulation (1646) was 160 units higher than the 78-year site average. Few (less than 150) units accumulated in April and October, most units accumulated in July, and diurnal difference in air temperature was ≈15 °C. Performance results from this study can assist cultivar site selection by comparing climate data for an intended site with that of Parma. For example, the low acidity and earliness of ‘Blauer Portugieser’ suggests it is best suited to a site with less heat unit accumulation than Parma, and the high acidity and late maturity of ‘Barbera’, ‘Nebbiolo’, and ‘Carignan’ suggest these cultivars are best suited to a site with more heat unit accumulation than Parma. The inconsistent relationship between onset of budbreak and earliness observed in this study suggests opportunity to match short-season cultivars late to break bud such as Flora to short-season growing sites prone to late-season frost.
Yield and Fruit Quality Traits of Carambola Cultivars Grown at Three Locations in Puerto Rico
Authors: Goenaga Ricardo
Published: December 2018

There is a scarcity of information on how carambola (Averrhoa carambola) cultivars perform in various agroenvironments. Nine carambola cultivars—Arkin, B-10, B-16, B-17, Kajang, Kari, Lara, Sri Kembangan, and Thai Knight—grown on an Oxisol, an Ultisol, and a Mollisol were evaluated for 4 years under intensive management at Isabela, Corozal, and Juana Díaz, PR, respectively. There were no significant differences in number and weight of marketable fruit per hectare area among locations averaging 258,761 fruit/ha and 30,978 kg·ha−1, respectively. There were no significant differences of marketable fruit weight per hectare among highest yielding cultivars B-17, Thai Knight, and Sri Kembangan between locations. The average marketable fruit weight for these highest-yielding cultivars was 36,060 kg·ha−1. ‘Arkin’ and ‘B-16’ were the lowest yielding cultivars, averaging 23,490 kg·ha−1 of marketable fruit. ‘Kari’ produced significantly longer fruit at all locations, whereas ‘B-16’ produced the shortest fruit. Significantly higher soluble solids concentration values were obtained from fruit of ‘B-17’ at all locations, whereas lower values were obtained from those of ‘Arkin’. Overall, cultivars were highly adaptable to the diverse agroenvironments in which they were planted. The fact that ‘B-17’ had high production of marketable fruit, high marketable yield, and high soluble solids concentration at all locations makes this cultivar suitable for planting in diverse agroenvironments.
Eradication of Phytophthora ramorum and Other Pathogens from Potting Medium or Soil by Treatment with Aerated Steam or Fumigation with Metam Sodium
Authors: Linderman R.G. , Davis E.A.
Published: December 2018

Phytophthora ramorum survived in potting media infested with sporangia or chlamydospores, allowing the pathogen to remain undetected while disseminated geographically. Chlamydospores or oospores of P. ramorum, Pythium irregulare, Thielaviopsis basicola, and Cylindrocladium scoparium produced in vermiculite culture were used to infest potting media. Infested media in plastic plug flats were treated with aerated steam mixtures from 45 to 70 °C for 30 min. In a second experiment, infested media were fumigated in polyethylene bags with a concentration series of metam sodium ranging from 0.25 to 1.0 mL·L−1. Survival of the pathogens was determined by selective baiting or direct plating the infested media on PARP selective medium. Assays indicated that all pathogens in the infested potting media were killed by aerated steam heat treatments of 50 °C or higher. Metam sodium concentrations of 1.0 mL·L−1 of medium or greater also eradicated all pathogens from the potting medium and soil. These results show that aerated steam treatment or fumigation with metam sodium can effectively sanitize soil-less potting media infested with P. ramorum or other soilborne pathogens, as well as P. ramorum-infested soil beneath infected plant containers. In addition, steam treatments to 70 °C did not melt plastic plug trays.
Growth of Chrysanthemum in a Pine Tree Substrate Requires Additional Fertilizer
Authors: Wright Robert D. , Jackson Brian E. , Browder Jake F. , Latimer Joyce G.
Published: December 2018

A pine tree substrate (PTS), produced by grinding loblolly pine trees (Pinus taeda), offers potential as a viable container substrate for greenhouse crops, but a better understanding of the fertilizer requirements for plant growth in PTS is needed. The purpose of this research was to determine the comparative fertilizer requirements for chrysanthemum (Chrysanthemum ×grandiflora ‘Baton Rouge’) grown in PTS or a commercial peat-lite (PL) substrate. The PTS was prepared by grinding coarse (1-inch × 1-inch × 0.5-inch) pine chips from debarked loblolly pine logs in a hammer mill fitted with 3/16-inch screen. The PL substrate composed of 45% peat, 15% perlite, 15% vermiculite, and 25% bark was used for comparative purposes. Rooted chrysanthemum cuttings were potted in each of the substrates on 15 Oct. 2005 and 12 Apr. 2006 and were glasshouse grown. Plants were fertilized with varying rates of a 20N–4.4P–16.6K-soluble fertilizer ranging from 50 to 400 mg·L−1 nitrogen (N) with each irrigation. Plant dry weights and extractable substrate nutrient levels were determined. In 2005 and 2006, it required about 100 mg·L−1 N more fertilizer for PTS compared to PL to obtain comparable growth. At any particular fertilizer level, substrate electrical conductivity and nutrient levels were higher for PL compared to PTS accounting for the higher fertilizer requirements for PTS. Possible reasons for the lower substrate nutrients levels with PTS are increased nutrient leaching in PTS due to PTS being more porous and having a lower cation exchange capacity than PL, and increased microbial immobilization of N in PTS compared to PL. This research demonstrates that PTS can be used to grow a traditional greenhouse crop if attention is given to fertilizer requirements.
Growth of Poinsettia as Affected by Cultivar, Thinning, and Pot Size
Authors: Goreta Smiljana , Batelja Kristina , Perica Slavko
Published: December 2018

The effect of thinning to three, four, five, or six lateral shoots on the growth parameters of five differently colored poinsettia (Euphorbia pulcherrima) cultivars (‘Christmas Star’, ‘Christmas Feelings’, ‘Cortez Candy’, ‘Marble Star’, and ‘Primero Roso’) was studied by consecutive measurements of growth from September to December. In a separate experiment, the effect of pot size (13-, 15-, or 18-cm diameter) on growth of ‘Christmas Star’ was studied. Cultivars responded similarly to thinning, but during the growing season, apparent differences in vegetative growth parameters between cultivars were observed, with ‘Primero Roso’ evaluated as the most vigorous. At the single-shoot level, the increased number of lateral shoots decreased the number of nodes at the beginning and the stem diameter at the end of the experiment. Leaf area, dry weight of stems, and total plant weight increased as the number of laterals increased at the end of experiment. The most distinctive canopy attribute in this study was the bract color because, according to customer evaluation, significant differences in visual appearance among tested cultivars were observed only for that trait. Pot size differentially affected the vegetative growth parameters of poinsettia ‘Christmas Star’. Increasing pot size from a 13- to 18-cm diameter resulted in an increase of plant canopy diameter, stem diameter, and the number of nodes on lateral shoots. There were no other substantial benefits on the measured growth parameters that could justify the use of pots larger than a 13-cm diameter for a poinsettia crop established at the beginning of September.
Preliminary Observations on Physiological Responses of Three Turfgrass Species to Traffic Stress
Authors: Han Lie-Bao , Song Gui-Long , Zhang Xunzhong
Published: December 2018

Traffic stress causes turfgrass injury and soil compaction but the underlying physiological mechanisms are not well documented. The objectives of this study were to investigate the physiological responses of kentucky bluegrass (Poa pratensis), tall fescue (Festuca arundinacea), and japanese zoysiagrass (Zoysia japonica) to three levels of traffic stress during the growing season under simulated soccer traffic conditions. Relative leaf water content (LWC), shoot density, leaf chlorophyll concentration (LCC), membrane permeability, and leaf antioxidant peroxidase (POD) activity were measured once per month. The traffic stress treatments caused a reduction in LWC, shoot density, LCC, and POD activity, and an increase in cell membrane permeability in all three species. Japanese zoysiagrass had less electrolyte leakage, and higher POD activity and shoot density than both kentucky bluegrass and tall fescue. The results suggest that turfgrass tolerance to traffic stress may be related to leaf antioxidant activity. Turfgrass species or cultivars with higher leaf antioxidant activity may be more tolerant to traffic stress than those with lower antioxidant activity.
Newspaper Mulches for Suppressing Weeds for Organic High-tunnel Cucumber Production
Authors: Sánchez Elsa , Lamont William J. , Orzolek Michael D.
Published: December 2018

Mulches usable in organic production were evaluated in high tunnels for their ability to suppress weeds. Mulch treatments were shredded newspaper, sheets of newspaper, straw, and a no-mulch control that was weeded once. Four cucumber (Cucumis sativus) cultivars were also evaluated. Yields were highest and fruit largest from ‘Sweet Marketmore’ and lowest from ‘Lemon’. Yields were unaffected by mulch treatments. Weed populations were highest in control plots and lowest in those with shredded newspaper. Cultivars did not affect weed populations. Sheets of newspaper degraded the most, followed by shredded newspaper and straw. Yields were not influenced by any mulch treatment, indicating weed populations remained below yield-depressing levels regardless of treatment.
A Case Study to Teach the Diagnostic Process: Determining the Cause of Chlorosis in a Crop of Cut Dicentra
Authors: Spaw Marci , Williams Kimberly A. , Hodges Laurie , Paparozzi Ellen T. , Mallberg Ingrid L.
Published: December 2018

This universally accessible, Web-based decision case presents the challenge of determining the cause of foliar chlorosis in a crop of dicentra (Dicentra spectabilis) being forced as a cut flower for Valentine's Day sales. The case study serves as a tool to promote the development of diagnostic skills for production dilemmas, including nutritional disorders, disease problems, and evaluation of the appropriateness of cultural practices. Cut dicentra is a minor crop and standard production practices are not well established. Solving this case requires that students research production protocol, as well as nutritional and pest problems, and determine whether they have enough information to recommend a solution. In this case study, a grower at Flint's Flower Farm must determine the cause of foliar chlorosis that is slowly appearing on about half the plants of her cut dicentra crop. The condition could be related to a number of possible problems, including a nutritional disorder, disease infection, or production practices. Resources are provided to aid students in gathering background information. Data accumulated by the grower are presented to allow students to eliminate unlikely solutions logically. The solution, which is unique to this crop, is provided along with detailed objectives and discussion points in teaching notes. This case study is complex in nature and is intended for use with advanced students in upper-level undergraduate courses of floriculture production, nutrient management, and plant pathology who have been previously exposed to the diagnostic process.
Two Simple and Inexpensive Laboratory Exercises for Teaching Agarose Gel Electrophoresis and DNA Fingerprinting
Authors: Trigiano R.N. , Ownley B.H. , Trigiano A.N. , Coley J. , Gwinn K.D. , Moulton J.K.
Published: December 2018

One of the most frequently used tools in plant biotechnology, which includes genomics and proteomics, is gel electrophoresis. Our experience with middle and high school students as well as teachers and undergraduate students is that they have very little, if any, hands-on experience with this technique. These exercises were developed to demonstrate the principles of electrophoresis and DNA fingerprinting in middle and high school and university laboratories with minimal expense and equipment. The experiments have been tested by middle and high school students, as well as by teachers, and undergraduate and graduate students. The first exercise, electrophoresis of common food dyes, is primarily designed for secondary and undergraduate students, but can be used as an inexpensive means for introducing the main concepts of electrophoresis to anyone who has little or no experience, including graduate students. Popular brands of food dyes (red, blue, yellow, and green) purchased at local markets are mixed into a 60% glycerol/water solution and are separated on 1% agarose gels using 100 V for 35 min. Mixed colors are separated into primary colors (e.g., green into blue and yellow) and some apparently single dyes often have extra “surprise” components. A simple exercise illustrating forensic use of gel electrophoresis with dyes is also included. Over 100 students and teachers have completed this experiment successfully. The second laboratory exercise requires more extensive equipment and a more advanced set of skills; however, the exercise has been completed successfully by middle school-level through graduate-level students and by teachers. In this exercise, the internally transcribed spacer region of the ribosomal subunit for a fungus, plant, and insect are amplified and separated electrophoretically on agarose gels. A simple crime is solved using polymerase chain reaction (PCR) and DNA fingerprinting. The experiment protocol provides students with hands-on activities that include assembling master mixes for PCR, practice using pipettes, and performing the various steps involved in PCR amplification. Instructions for both exercises are formatted in easy-to-follow procedure boxes, and a downloadable presentation is available on the web. The cost of the expendables is about $1 per student, making these exercises relatively inexpensive to conduct, assuming that hardware and DNA are available.
Gibberellic Acid Accelerates ‘Honeycrisp’, but not ‘Cameo’, Apple Fruit Maturation
Authors: Schmidt Torrance R. , Elfving Don C. , McFerson James R. , Whiting Matthew D.
Published: December 2018

Gibberellins inhibit flowering in apple (Malus domestica) and show promise as tools to promote annual bearing. The authors validated the efficacy of gibberellic acid (GA) to reduce return bloom dramatically in two biennial cultivars. ‘Honeycrisp’ fruit treated in 2004 with GA4+7 at 0, 200, 400, or 600 mg·L−1 demonstrated advanced maturity in terms of starch levels, flesh firmness, and titratable acidity, whereas ‘Cameo’ fruit showed variable treatment effects. In 2005, 0, 300, 600, 900, or 1200 mg·L−1 GA4+7 was applied to ‘Cameo’, and fruit maturity was once again unaffected. Two commercial GA products (GA4, GA4+7) were applied in 2005 to ‘Honeycrisp’ at 400 mg·L−1. Both formulations caused fruit to have less flesh firmness and acidity, and increased levels of starch conversion compared with the untreated control at harvest and after 140 d of common storage. All GA treatments in all four trials profoundly diminished flowering in the season after treatment. Results demonstrate differences in sensitivity to GA between the two cultivars.
Juneberry Growth Is Affected by Weed Control Methods
Authors: Willard Deborah , Valenti Harlene Hatterman
Published: December 2018

Weed control is necessary to ensure success in early stages of juneberry (Amelanchier alnifolia) orchard development; however, juneberry growers have limited chemical weed control options. A field trial was initiated at Prosper, ND, to evaluate the efficacy of physical and chemical weed control methods and their effects on juneberry growth. Woven landscape fabric most effectively eliminated weed emergence, whereas winter rye (Secale cereale) cover crop allowed the most weeds to emerge throughout the study. During both years, a hairy vetch (Vicia villosa) companion crop provided poor early- to midseason weed control, but weed suppression increased over time as hairy vetch grew to cover open areas. However, hairy vetch was very competitive with juneberry, reducing crop height, width, and overall growth. Plants within the herbicide treatments (glyphosate at 0.75 lb/acre plus oryzalin at 2 lb/acre and linuron at 1.7 lb/acre followed by flumioxazin at 1 oz/acre) and the hand-weeded control, which was weeded three times each year, had the greatest growth.
Quality Assessment of Two Commercially Available Species of Entomopathogenic Nematodes: Steinernema feltiae and Heterorhabditis indica
Authors: Caamano Erick X. , Cloyd Raymond A. , Solter Leellen F. , Fallon Declan J.
Published: December 2018

The quality of entomopathogenic nematodes (EPN) is critical to their success as biological control agents, but it is difficult to evaluate quality because standard procedures are not available. Generally, the quality of biological control agents is determined by field performance because end users may have minimal knowledge pertaining to the condition of biological control agents before application. This study assessed the variability in quality of commercially available EPN products. The authors evaluated preapplication survival of five EPN formulations, Steinernema feltiae (NemaShield, Nemasys, Gnat Not, Horticultural Scanmask), and Heterorhabditis indica (GrubStake-Hi), based on eight shipments/samples of each EPN product received during a 5-month period (July to November). The estimated total number of EPN delivered per shipment (i.e., sample) was compared with the expected quantity listed on the label, and percent live EPN was determined for each shipment. One-half of the shipments of Gnat Not (four of eight) contained 40% to 70% of the number of EPN expected based on the label (25 million). The remaining shipments contained consistently higher numbers, with 99% of the expected quantity of EPN received. Entomopathogenic nematode mean percent survival was highest for Nemasys (98%) and lowest for Horticultural Scanmask (56%). The overall mean percent survival for Gnat Not and GrubStake-Hi, both from the same supplier, was more than 85%. Survival of EPN in the NemaShield product was as low as 50%, but was typically between 65% and 75%. NemaShield and Nemasys were the only two EPN products that provided return policy information if the product was damaged in any way. It is important for distributors and suppliers to ensure that EPN products are in quality condition before shipping to avoid performance failures and loss of customers. In addition, end users need to evaluate shipments upon receipt to determine the viability of EPN products.
Fifty-five Years of Yield Improvement for Cucumber, Melon, and Watermelon in the United States
Authors: Gusmini Gabriele , Wehner Todd C.
Published: December 2018

Yield data for the major cucurbit crops in the United States have been collected and summarized. Yield trends are presented for cucumber (Cucumis sativus; processing and fresh-market), melon (Cucumis melo; muskmelon and honeydew), and watermelon (Citrullus lanatus) for the period 1951–2005. Data have been obtained from the U.S. Department of Agriculture, as originally reported by six of its units: Agricultural Marketing Service, Agricultural Research Service, Bureau of Agricultural Economics, Economic Statistics Service, National Agricultural Statistics Service, and Statistical Reporting Service. For all crops yields have been increasing over time, except for processing cucumber, for which yields seem to have reached a plateau by the end of the 1990s.
Ralstonia solanacearum Race 4: Risk Assessment for Edible Ginger and Floricultural Ginger Industries in Hawaii
Authors: Paret Mathews L. , de Silva Asoka S. , Criley Richard A. , Alvarez Anne M.
Published: December 2018

Fourteen species of ginger belonging to Zingiberaceae and Costaceae were evaluated for susceptibility to the bacterial wilt pathogen Ralstonia solanacearum (Rs) race 4 (ginger strains) by several methods of inoculation, including tests to simulate natural infection. Twelve of 14 species tested were highly susceptible to all strains of Rs race 4 upon stem inoculation, and susceptible plants wilted within 21 days. In contrast to previous reports that Rs strains from an invasive alien species, kahili ginger (Hedychium gardenarium), are nonpathogenic on ornamental gingers, the kahili ginger strain wilted both ornamental and edible ginger (Zingiber officinale) species within 21 days. Pour inoculation to the base of 11 plant species to simulate natural infection confirmed the ability of Rs to invade all the tested species without root wounds. Shampoo ginger (Zingiber zerumbet) was the most susceptible (wilted in 26 days) whereas pink ginger (Alpinia purpurata) and red ginger (A. purpurata) were the least susceptible and wilted in 71 and 76 days respectively. Pathogen survival in potting medium was evaluated by enumerating viable cells in effluent water from drenched pots with and without infected edible ginger after stem or rhizome inoculation. Ralstonia solanacearum survived in plant-free potting medium for 120 days and for 150 to 180 days in potting medium with infected edible ginger. The ability of Rs race 4 to infect many ginger species without wounding and to survive for long periods indicates that high risks will be incurred if the kahili ginger strain is inadvertently introduced from the forest reserves into ginger production areas.
Effect of Cultivar, Controlled Atmosphere Storage, and Fruit Ripeness on the Long-term Storage of Highbush Blueberries
Authors: Hancock Jim , Callow Pete , Serçe Sedat , Hanson Eric , Beaudry Randy
Published: December 2018

Controlled-atmosphere storage had little effect on the quality of fruit of eight cultivars held under 2 kPa oxygen (O2) and 8 kPa carbon dioxide (CO2) versus ambient air. ‘Elliott’ fruit harvested from bushes with only 30% ripe fruit had significantly better storage quality than fruit picked later; however, there was no significant difference in the storage life of fruit that was stored fully blue versus partially green. Fruit from the first harvest of four cultivars had superior storage quality to that of the second. In one comparison of the long-term storability of nine cultivars, ‘Bluegold’, ‘Brigitta’, and ‘Legacy’ performed the best, storing for 4 to 7 weeks. In another postharvest trial of 17 cultivars, ‘Brigitta’ stored the longest (8 weeks) followed by ‘Aurora’ and ‘Draper’ (7 weeks). The most resistant genotypes to Alternaria spp. were ‘Brigitta’, ‘Aurora’, ‘Elliott’, and ‘Draper’, whereas the most resistant genotypes to Colletotrichum spp. were ‘Elliott’, ‘Brigitta’, ‘Toro’, ‘Draper’, and ‘Bluejay’.
Evaluation of Table Grape Storage in Boxes with Sulfur Dioxide-releasing Pads with Either an Internal Plastic Liner or External Wrap
Authors: Lichter Ammon , Zutahy Yohanan , Kaplunov Tatiána , Lurie Susan
Published: December 2018

Two main methods are in use for packing table grapes (Vitis vinifera) for refrigerated storage and transport. One is to pack the grapes with a sulfur dioxide (SO2) generator pad inside a box with a perforated plastic liner and then to cool them. The other is to place the SO2 pad on the grapes, cool the pallet, and wrap it with low-density polyethylene film, leaving the bottom of the pallet open. These two methods were compared for their efficiency in maintaining grape quality and preventing decay for periods ranging from 33 to 117 days. The experiments included ‘Redglobe’ and ‘Zainy’ grapes packaged in plastic boxes and ‘Thompson Seedless’ grapes packaged in cardboard boxes. The quality of the grapes in the trials with plastic boxes was either similar in both packaging methods or better in the wrapped pallet than the liner method. The pedicels, and sometimes the rachis, showed more desiccation in the liners than in the wrapped pallets. Prevention of decay was also better with the wrapped pallets than for storage in liners. However, in the experiment with cardboard boxes, the externally wrapped boxes contained lower levels of SO2, probably because of absorption of SO2 by the cardboard, and the grapes developed more decay and rachis desiccation than in liners inside the cardboard boxes. The method of wrapping grapes after cooling them can have significant advantages over the liner method because of the faster cooling of the grapes and the use of less plastic-based, nonrecyclable materials.
Effects of Organic Fertilization and Cover Crops on an Organic Pepper System
Authors: Delate K. , Cambardella C. , McKern A.
Published: December 2018

With the continuing 20% growth rate in the organic industry, organic vegetable crop production has increased to 98,525 acres in the United States. The requirement for certified organic vegetable producers to implement a soil-building plan has led to the development of soil fertility systems based on combinations of organic fertilizers and cover crops. To determine optimal soil fertility combinations, conventional and organic bell pepper (Capsicum annuum) production was evaluated from 2001 to 2003 in Iowa, comparing combinations of two synthetic fertilizers and three compost-based organic fertilizers, and a cover crop treatment of hairy vetch (Vicia villosa) and rye (Secale cereale) in a strip-tilled or fully incorporated cover crop system. Organic pepper growth and yields equaled or surpassed conventional production when nitrogen (N) was provided at 56 or 112 kg·ha−1 from compost-based organic fertilizer. Soil analysis revealed higher N in plots where cover crops were tilled compared with strip-tilled plots, leading to recommendations for sidedressing N in strip-tilled organic pepper production. Increased incidence of disease was also detected in strip-tilled plots. Postharvest weight loss after 6 weeks in storage was similar in organic and conventional peppers. The addition of calcium and sulfur products in conventional or organic fertilizer regimes did not increase pepper production or postharvest storage potential. Despite application challenges, cover crops will remain as critical components of the organic farm plan for their soil-building benefits, but supplementation with approved N sources may be required for optimal pepper production. Organic growers should conduct their own tests of organic-compliant soil amendments to determine cost effectiveness and value for their site before large-scale application.
Organic Fertility Sources for the Production of Short-day Organic Onion Transplants
Authors: Boyhan George E. , Hill C. Randy
Published: December 2018

This study evaluated poultry litter, commercial organic fertilizer, and compost for organic production of onion (Allium cepa) transplants within the Vidalia onion growing region of southeastern Georgia. Two field experiments were conducted. The first experiment tested six rates of poultry litter (0–10 tons/acre). The second experiment tested a factorial combination of two rates of nitrogen (N) (0 and 130 lb/acre) and three rates of compost (0, 5, and 10 tons/acre). Seedling weight, length, and diameter were measured ≈10 weeks after sowing. Poultry litter had a significant increasing linear effect on plant weight and diameter. There was also a significant increasing quadratic effect on plant length. Commercial organic fertilizer (3N–0.9P–2.5K) at 130 lb/acre N had a significant effect on plant length, but compost at 0, 5, or 10 tons/acre did not affect plant length. There were organic fertilizer by compost interactions for plant weight and diameter. There was a significant effect on plant diameter with organic fertilizer (130 lb/acre N) and 10 tons/acre compost, but there was no fertilizer effect on plant diameter at 0 or 5 tons/acre compost. The interaction effect on plant weight indicated there was a significant effect from fertilizer with 5 and 10 tons/acre compost, but not with 0 tons/acre. Based on this study, nutrition should not be a problem in producing organic onion transplants in southeastern Georgia. Four to 6 tons/acre fresh poultry litter should be adequate for producing good quality transplants. An alternative approach of using organic fertilizer at a rate of 130 lb/acre N with 5 to 10 tons/acre compost can also be used to produce good quality transplants.
The Relationship Between Student Use of Campus Green Spaces and Perceptions of Quality of Life
Authors: McFarland A.L. , Waliczek T.M. , Zajicek J.M.
Published: December 2018

Researchers have found that students' perception of their overall academic experience and the campus environment is related to academic accomplishment. Additionally, studies have found that the designed environment of the university can influence the degree of stress students may feel. The main objective of this study was to investigate the relationship between undergraduate university student use of campus green spaces and their perceptions of quality of life at a university in Texas. A total of 2334 students or 10% of the undergraduate student body received e-mails with information regarding the incentive for participation and instructions on accessing an online survey. The survey included questions that related to student use of campus green spaces, overall quality of life statements, an instrument to measure the quality of life of university students, and demographic questions. A total of 373 surveys was collected and analyzed to compare levels of quality of life of university students and the level of usage of campus green spaces. Demographic information collected allowed controlling for student grade classification, gender, and ethnicity. Frequency statistics determined that, on average, more than half the students were ranked as “high-users” of the campus green spaces, and very few students were considered “low-users.” Frequency statistics also determined that most students rated their overall quality of life and quality of life of university students positively. Additionally, this study found that undergraduate student use of campus green spaces and perceptions of quality of life were related to each other.
Tolerance of Three Juniper Species to Glyphosate
Authors: Czarnota M.A.
Published: December 2018

Glyphosate traditionally has been used by growers and landscapers as a nonselective herbicide; however, selective uses do exist. The use of glyphosate to control weeds in dormant and actively growing bermudagrass (Cynodon dactylon) is an example of selective weed control. Several ornamentals, including conifer species, have been known to exhibit good tolerance to over-the-top applications of glyphosate. Unfortunately, little published information exists on rates of glyphosate that may be used on specific ornamental species. The objective of this research was to determine the tolerance levels of three juniper species [‘Blue Pacific’ shore juniper (Juniperus conferta), ‘Blue Star’ juniper (Juniperus squamata), and ‘Parsoni’ juniper (Juniperus davurica)] to various rates of glyphosate. Research conducted in 2004 and 2005 indicated that injury to three juniper species did not exceed 23% with glyphosate rates up to 2.5 lb/acre.