bluuebunny/crossref_metadata_2025 huggingface dataset:
326 Quantification of Reduced Sugars, Starch, and Total Soluble Carbohydrates in Potato Plantlets Cultivated in Vitro in Media with Different Sucrose Concentrations
Authors: de Franca Rosilene Barbosa , de Luces Fortes Gerson Renan , Nesi Adriano Nunes
Published: February 2019

The aim of this work was to evaluate the effect of sucrose on the in vitro muliplication of potato, cultivars Baronesa, Macaca, and Cristal. The nutrient medium used was the MS basal salts and vitamins added to 100 mg·L-1 myo-inositol. Four sucrose concentrations (20, 30, 40, and 50 g·L-1) were tested. The pH was adjusted to 5.9 before autoclaving. Each treatment had 15 explants, which were collected from the lower part of the shoot containing two buds. This material was inoculated in a 250-mL flask with 40 mL of nutrient medium. After inoculation the flasks were kept in a growth room under 25 ± 2 °C, 16-h photoperiod, and 19 μMol·m-2·s-1 radiation provided by cool-white fluorescent lamps for 30 days. This trial was designed in a randomized block with three replicates. Every 7 days, the parameters were collected as follows: number of buds, shoot length and number of shoots. It was observed that `Baronesa' presented the highest number of buds and rate of multiplication. `Cristal' had a slightly better performance for these parameters. Plants treated with sucrose at 50 g·L-1 led to a higher number of shoots. However, `Macaca' treated with sucrose at 40 g·L-1 had the highest shoot length.
329 Evaluation of Textile Fiber Residues for Horticultural Use
Authors: Wees D. , Lowe R. , Donnelly D.
Published: February 2019

Textile fiber residues spun into small (2 to 5 mm), soft pellets (Flocagro®), through a patented process, were evaluated for horticultural use. Pellets alone and in mixtures with other substrates, were assessed using standard criteria including cation exchange capacity (CEC), aeration porosity, bulk density, and water-holding capacity. The physical and chemical properties of these textile pellets were acceptable as a horticultural growing medium when mixed with substrates such as peat; it was light-weight, had a high water-holding capacity, moderately high aeration porosity, neutral pH, low inherent fertility, low buffering capacity, and mixed easily with other substrates. The potential of Flocagro® in potting mixtures for radish and tomato seedlings and micropropagated potato plantlets was demonstrated.
331 Effects of Explant Type, Sucrose Level and Callus Development Time on In Vitro Plant Regeneration of Sweetpotato
Authors: Chen L. , Park S.O. , Dhir S. , Bhagsari A.S.
Published: February 2019

Several experiments were conducted to evaluate the influence of explant type, sucrose level, and callus development time on sweetpotato [Ipomoea batatas (L.) Lam] in vitro culture. Shoot tip, petiole, and leaf of Selection 75-96-1 was used as explants in Murashige and Skoog (MS) media with different plant growth regulators. Calli derived from shoot tip and petiole produced 42.1% and 10.3% somatic embryos, respectively, but the leaf failed to produce somatic embryos. The effect of sucrose level was determined using shoot tip as explants. Compared with 3% sucrose in the same plant growth regulators level medium during callus initiation and callus proliferation periods, 5% sucrose level suppressed root growth and improved shoot regeneration. The callus development time was measured by using shoot tips on callus initiation medium containing 1.5 mg/L alpha-Naphthaleneacetic acid (NAA) and 0.25 mg/L Kinetin (KIN) plus 5% sucrose. When explants were cultured for less than 6 weeks during callus initiation, then transferred onto plant regeneration medium, plant regeneration via organogenesis occurred; whereas, maintaining cultures for more than 12 weeks on the same callus initiation/proliferation medium, plant regeneration was favored via embryogenesis. Explant type and other factors affecting plant regeneration noted here could be applied to protoplast culture, somatic hybridization, and transformation in sweetpotato.
332 Enhancement of Microtuber Production in Temporary Immersion Bioreactors with Ancymidol
Authors: Desjardins Y. , Abdulnour J.
Published: February 2019

Microtubers (Solanum tuberosum cv Snowden) were produced in 1-L jar fermentors using a two-step method consisting of a shoot multiplication phase (21 days) followed by a tuberization phase (25 days). The plantlets were immersed in Murashige and Skoog (MS) liquid medium for 3.5 min every 4 h. Low concentrations of ancymidol (anti-gibberellic substance), particularly during the shoot multiplication phase, were essential for tuber initiation and development. A continuous supply of 2 μMol ancymidol during the two phases of culture decreased plant height, but produced >100 microtubers per jar. Although the tuber development phase was short (25 d), 25% of the microtubers produced were >0.5 g with 17.5% to 18.0% of dry-matter content.
339 Chlorophyll Content is Negatively Correlated with Muskmelon Seed Quality
Authors: Cotton Corrie , Welbaum Gregory E.
Published: February 2019

Maturity at harvest determines seed viability and vigor. However, separating seeds from different stages of development can be difficult using existing seed sorting technologies. New technology non-destructively sorts seeds based on their chlorophyll fluorescence (CF), so seeds with the same dry weight but with different physiological maturates can be separated. We determined whether chlorophyll content of muskmelon (Cucumis melo L. cv. Top Mark) seeds changes during development and whether those changes were related to viability and vigor. Seed viability and vigor were determined using an Association of Official Seed Analysts wet paper towel germination test. `Top Mark' seeds from nine stages of development were run through the SeedMaster Analyzer (Satake USA Inc., Houston, Texas), which calculated the chlorophyll content of each seed. The CF signal was fed into a computer to obtain a frequency histogram. Forty, 45, and 55 days after anthesis (DAA) seeds had germination percentages of 96%, 98%, and 100%, respectively, the highest in the study. Fifty-five DAA had greater seed vigor and viability and contained the lowest CF values; 207 on the 1000-value scale. The less-mature seeds contained higher chlorophyll content and had the lowest seed vigor and viability. Seed vigor and chlorophyll content were negatively correlated in this study. All seeds with high CF values had low vigor, but not all seeds with low CF values have high vigor. Seed aging during storage can reduce viability and vigor independent of chlorophyll content. Based on chlorophyll content, the SeedMaster Analyzer can non-destructively remove immature, low-vigor seeds that have the same physical characteristics and weight as more mature seeds. Chlorophyll fluorescence technology may allow the seed industry to further improve seed quality and maximize vigor.
340 The Plant Tissue Culture Information Exchange Media Database
Authors: Herring April S. , Lineberger R. Daniel
Published: February 2019

The Univ. of Minnesota hosts the PLANT-TC Listserv as a service to the international tissue culture community (http://www.agro.agri.umn.edu/plant-tc/listserv/). One of the most frequently sought types of information is a recommendation for a “beginning point” for culturing a wide variety of plant species. Many of these inquiries come from individuals without ready access to extensive library holdings, including those in industry, public schools, and international sites. A Web site prototype that includes a searchable database of tissue culture recipes is being constructed and offered for user input. The database currently is located at http://webtutor.tamu.edu/students/herring/project/, but will be redirected to its own URL if user feedback is positive. The database also includes information about equipment and materials, media suppliers and domestic and foreign sources for tissue cultures and micropropagated plants. Other educational resources, including a virtual tour of a commercial tissue culture lab, are available on the site. The Web site and database will be reviewed by a panel of experts and modified according to their input prior to being posted for public access.
348 In Vitro Establishment and Growth of Bermudagrass, Buffalograss, Saltgrass, and Zoysiagrass
Authors: Hughes Harrison , Towill Leigh
Published: February 2019

There are turfgrasses species that are clonally propagated; notably bermudagrass, buffalograss, and zoysiagrass. Some of the early cultivars of these species are no longer widely grown, and may eventually be lost if not preserved. In order to facilitate studies on the long-term cryopreservation of these species and specific lines of saltgrass, it is necessary to develop suitable micropropagation procedures. We have developed protocol for the isolation and establishment of clean cultures in vitro for all four species. A 1/2-strength MS basal medium with Nitsch & Nitsch vitamins, 5 mg/L of thiamine, 2 mg/L of glycine, 30 g of sucrose, 7 g of agar with varying growth regulators has been used. Explant materials are prewashed in the greenhouse prior to a 15- to 30-min soapy wash in the laboratory. After a 30- to 60-min rinse in running water, nodal sections are surface-disinfested in 10% bleach with Tween 20 for 15 min, followed by three sterile water rinses. This procedure, sometimes with PPM (a proprietary antimicrobial compound), results in 50% or greater clean cultures. Rapidly growing nodal sections work best and preferably those not established in soil. We have tested various growth regulator combinations and have found that 10 mg/L of BA results in proliferation of buffalograss and saltgrass. However, proliferation remains relatively slow, requiring 8 to 12 weeks to develop sufficiently for subculture. Although we have succeeded in obtaining clean cultures of bermudagrass and zoysiagrass, proliferation is minimal, Further research is ongoing to develop a proliferative system with these two species.
350 Response of Dominican Oregano (Lippia micromera Schan.) to Nitrogen, Phosphorus, and Potassium Fertilization
Authors: Morales-Payan J. Pablo
Published: February 2019

Dominican oregano is a traditional seasoning leaf in Caribbean cuisine. However, little information is available regarding its mineral nutrition when grown as a commercial crop. Field studies were conducted to determine the short-term response of recently transplanted Dominican oregano to N, P, and K in a clay soil. Dominican oregano plants 15 to 20 cm tall were used. A randomized complete-block design with 13 treatments and three replications was utilized. Treatments were 0 fertilization (control) and 20, 40, 60, and 80 kg/ha of N, P2O5, or K2O applied 20 days after transplanting. Experimental units consisted of 12 plants at with a distancing of 1.0 × 1.0 m. Above-ground biomass accumulation was determined 3 months after treatment. Analysis of variance and regression analysis was performed on the resulting data. Biomass accumulation in Dominican oregano was significantly influenced by N, P, and K fertilization rates. Crop yield increased linearly as nutrient rates increased. Nitrogen fertilization had a stronger influence on Dominican oregano biomass accumulation than P and K fertilization. Results indicate that fertilizing Dominican oregano increases its biomass yield. However, due to its seasoning nature, the effect of mineral fertilization on the essential oils of this crop must be analyzed.
357 Nutraceutical Roles of Polyphenolic Compounds from Berry Fruits
Authors: Smith M.A.L. , Seigler D. , Kandil F.E.
Published: February 2019

Polyphenolic compounds (particularly anthocyanins, proanthocyanidins, and other flavonoids) from some fruits and vegetables have significant and diverse impacts on human health preservation. While it's well recognized that some of the polyphenolics in foods we consume have a protective and proactive role against disease, very little has been known about how they accomplish this feat. A range of bioassays (in vitro and in laboratory animals) were adapted to examine compounds extracted from berry fruits, and separated into distinct fractions by vacuum chromatography. The proanthocyanidin class of compounds, as well as mixtures of proanthocyanidins and other flavonoids, were significantly bioactive against both the promotion and initiation stages of chemically-induced carcinogenesis. Potent antioxidant activity was not confined to particular fractions, but was present in several classes of compounds. Identification and characterization of the bioflavonoids is complicated both by apparent interactions between related compounds that occur together within horticultural fruits, and interferences from some substances (pectins and complex sugars) that depress observed response in bioactivity assays.
358 Nitrogen Fertilization and Lychee Flowering and Production in Southern Florida
Authors: Li Yuncong , Davenport Tom , Rao Renuka , Zheng Qi
Published: February 2019

Despite the increasing popularity in American markets of the fruit of the illustrious lychee (Litchi chinensis Sonn.), unreliable flowering and yield has had serious impacts on lychee growers in southern Florida. Lychee flowering is normally induced by chilling temperatures. Unpredictable weather, high rainfall, and excessive nutrients cause unreliable flowering in southern Florida. Although growers have no control over the weather, they need to be able to manage the growth, vigor, and reproduction of trees through practices that optimize flowering. When excessively watered and fertilized, lychee trees grow vigorously with frequent vegetative flushes every 2 to 3 months. The lack of maturity of these late vegetative flushes prevents flower stimulation from mild temperatures in January and February, when flowering typically occurs on trees that have not experienced vegetative flushes in the late fall or early winter. Thus, by adopting nitrogen fertilizer management practice, growers should be able to induce abundant flowering even in mild winters. Our preliminary results demonstrated that timing and rates of applications of nitrogen fertilizer significantly affected concentrations of soil and leaf N. High nitrogen levels in the leaves induced more vegetative flushes and less flowering, and consequently less fruit yield.
366 Nitrogen Fertigation of Young Navel Orange Trees
Authors: Weinert T.L. , White S.A. , Thompson T.L. , Maurer M.A.
Published: February 2019

Citrus production in the southwestern U.S. is highly dependent on inputs of irrigation and N fertilizer to achieve optimum fruit yield and quality. Microsprinkler irrigation may allow for substantial increase in efficiency of N and water application. However, best management practices have not yet been developed for microsprinkler use, particularly on newly established citrus trees. Experiments were conducted during 1997–98 in central Arizona to evaluate the effects of various N rates and fertigation frequencies on growth and N partitioning in young `Newhall' navel oranges planted in Apr. 1997. Two experiments were conducted, each with factorial combinations of N rate and fertigation frequency. In one experiment, non-labeled N fertilizer was used and in the other 15N-labeled N fertilizer. Trunk diameter, leaf N, and 15N partitioning in the trees were measured. During 1997, neither trunk diameter or leaf N were affected by N rate or fertigation frequency. No more than 6% of the N applied was taken up by the trees, and about 50% of the fertilizer N taken up was found in the leaves. Trees grew much more rapidly in 1998. Leaf N in fertilized plots was significantly higher than in control plots, but leaf N in all trees remained above the critical level of 2.5%. Despite rapid tree growth during 1998, no more than 25% of the fertilizer N applied was taken up by the trees. About 60% of the fertilizer N taken up was found in the leaves. Results suggest that N applications are not needed during the first growing season after planting for microsprinkler-irrigated citrus trees in the Southwest. Only modest rates (68 to 136 g/tree) will be needed during the second season to maintain adequate tree reserves.
367 Scavenging Capacity of Active Oxygen Species in Blackberry
Authors: Wang Shiow Y. , Jiao Hongjun
Published: February 2019

The effect of blackberries (Rubus sp.) genotypes on antioxidant activities against superoxide radicals (O2–), hydrogen peroxide (H2O2), hydroxyl radicals (OH), and singlet oxygen (O,), was evaluated. The results were expressed as percent inhibition of active oxygen species production in the presence of fruit juice. The active oxygen radical absorbance capacity (ORAC) value referred to the net protection in the presence of fruit juice, and was expressed as micromoles of α-tocopherol, ascorbate, α-tocopherol, and β-carotene equivalents per 10 g of fresh weight for O2–, H2O2, OH, and O2, respectively. Among the different cultivars, juice of Hull' blackberry had the highest oxygen species, superoxide radicals (O2–), hydrogen peroxide (H2O2), hydroxyl radicals (OH), and singlet oxygen (O2,) scavenging capacity. Different antioxidants have their functional scavenging capacity against active oxygen species. There were interesting and marked differences among the different antioxidants in their abilities to inhibit the different active oxygen species. β-carotene had by far the highest scavenging activity against O2– but had absolutely no effect on H2O2. Ascorbic acid was the best at inhibiting H2O2 free radical activity. For OH, there was a wide range of scavenging capacities with α-tocopherol the highest and ascorbic acid the lowest. Glutathione had higher O2– scavenging capacity compared to the other antioxidants.
369 Influence of Temperature and Product on Nutrient Release Patterns of Three Polymer-coated Fertilizers
Authors: Husby Chad E. , Niemiera Alex X. , Wright Robert D. , Harris J. Roger
Published: February 2019

Use of polymer-coated fertilizers (PCFs) is widespread in the nursery and greenhouse industries. Temperature is the main factor affecting nutrient release from PCFs, yet there are few reports that quantify temperature-induced nutrient release. Since container substrate temperatures can be at least 40 °C during the summer, this research quantified the release of fertilizer salts in the diurnal container substrate temperature range of 20 to 40 °C. Three PCFs (Osmocote Plus 15-9-11, Polyon 18-6-12, and Nutricote18-6-8) were placed in water-filled beakers at 40 °C until one-third (Expt.1) or two-thirds (Expt. 2) of Osmocote's N was released. For Expts. 1 and 2, each fertilizer was put into sand-filled columns and leached with distilled water concurrent with column temperature incrementally increasing from 20 to 40 °C and then to 20 °C over a 20-h period. Leachate fractions were collected at every 2 °C increase and analyzed for fertilizer salts. In Expt.1 and in the range of 22 to 30 °C, salt release was highest, lowest, and intermediate for Nutricote, Osmocote, and Polyon, respectively. In the range of 38 to 40 °C, release was highest, lowest, and intermediate for Osmocote, Nutricote, and Polyon, respectively. In Expt. 2, salt release in the range of 22 to 30 °C was the same as in Expt. 1. However, at 38 to 40 °C, release was highest, lowest, and intermediate for Polyon, Nutricote, and Osmocote, respectively. Results show that salt release for PCFs are dependent on the temperature × fertilizer age interaction.
373 Response of Dwarf Yaupon Holly to Fertilizer Rate and Duration
Authors: Yeager Thomas , Larsen Claudia , Martins Gisele
Published: February 2019

Multiple branched liners of Ilex vomitoria Ait. `Nana' were greenhouse-grown in 3-L containers with a 2 pine bark: 1 Canadian peat: 1 sand substrate. Plants were fertilized weekly with a solution of 50 N, 10 P, and 30 K (mg·L–1) for either 5, 10, or 15 weeks. Then plants for each of the three fertilizer durations were fertilized weekly with a solution of either 50, 150 or 300 N, 10 P, and 30 K (mg·L– 1) for an additional 15 weeks, at which time root and shoot dry weights were determined. A control group of plants was fertilized weekly with 300 N (mg·L–1) for 30 weeks. Shoot dry weight increased linearly as fertilizer rate or duration of fertilization increased. Root dry weights increased linearly as fertilizer duration increased while root dry weights were not different due to fertilizer rate. These data indicate that duration of fertilization is important in promoting root and shoot growth; however, the largest amount of root and shoot dry weight resulted from the highest N application rate (300 mg·L–1) for the longest duration (30 weeks).
374 Interactions of Temperature and Fertilizer Concentration Affect Growth of Petunia and Geranium
Authors: Kang Jong-Goo , van Iersel Marc
Published: February 2019

Fertilizer recommendations for fertilizing bedding plants are normally based on nitrogen content of the fertilizer solution. However, nutrient availability is more closely related to the concentration of nutrients in the growing medium than the concentration in the fertilizer solution. Environmental conditions can affect the accumulation of nutrients in the growing medium and optimal fertilizer concentrations are likely to depend on environmental conditions. To test this hypothesis, we grew petunias and geraniums under three temperature regimes (35 °C/27C, 25 °C/17C, and 15 °C/7 °C) and with five concentrations of fertilizers [electrical conductivity (EC) of 0.15, 1, 2, 3, and 4 dS·m–1]. Temperature and fertilizer EC affected the plant growth. Optimal fertilizer EC decreased as temperature increased. Growth was better correlated with EC of the growing medium than with EC of the fertilizer solution. Irrespective of growing temperature, plant growth was best when EC of the growing medium was between 3 and 4 dS·m–1. A lower growing medium EC slowed down growth, presumably because of mild nutrient deficiencies. Higher fertilizer concentrations in the growing medium (>4 dS·m–1) decreased growth because of salt stress. The EC of the growing medium increased with increasing EC of the fertilizer solution and with increasing temperature. Because of the interactive effect of fertilizer concentration and temperature on the EC of the growing medium, plants should be grown with more dilute fertilizer solutions at higher temperatures. Fertilization guidelines for growers should be based on maintaining the EC of the growing medium within an optimal range instead of the more traditional recommendations based on the concentration of the fertilizer solution.
375 Low Phosphorus Controls Bedding Plant Growth
Authors: Cox Douglas
Published: February 2019

`Ultra Red' petunia (Petunia × hybrida Hort. Vilm.-Andr.), `Bonanza Orange' marigold (Tagetes patula L.), and `Marglobe' tomato (Lycopersicon esculentum Mill.) were fertilized with a low-P, water-soluble fertilizer to evaluate the potential of low-P nutrition to control growth. Beginning at transplanting, plants received N at 150 mg·L–1 fertilizer solutions twice a week until finish from 20N–4.3P–16.6K continuously (control), 20N–0P–16.6K continuously, or four or six applications of 20N–0P–16.6K followed by 20N–4.3P–16.6K to finish. Growth media were two commercial soilless substrates (Fafard 3B and Metro Mix 360), and a 2 sphagnum peat moss: 1 perlite: 1 vermiculite combination (v/v) containing no starter or granular P fertilizer. All species in the 2:1:1 growth medium responded to low P treatments with significant growth reductions. In the commercial media, presumably due to the presence of a P-containing starter fertilizer, there were no visible effects of low P on the size of ornamental species and only small reductions in the measured growth characteristics compared to the control. Tomato growth, however, was significantly reduced by low P treatments in both commercial media. This research suggests that the P requirement of some ornamental bedding species is very low and that to use low P for growth control, plants must be grown in a substrate containing no P fertilizer. Under these conditions, four or six applications of 20N–0P–16.6K followed by 20N–4.3P–16.6K to finish resulted in desirable growth reductions and no P deficiency symptoms.
379 Substrate and Nutrient Variations for Optimization of Commercial Cultivation of Anthurium andreanum var.Honduras
Authors: Prasad P.V. Devi , Chun P. Tai , Potluri S.D.P.
Published: February 2019

The Production of the cut flowers of Anthurium andreanum was in decline after Hurricane Gilbert in 1988 and the subsequent wide-spread problem of bacterial blight in Jamaica and the Caribbean. New methods of cultivation and new varieties were necessary for the development of the industry. In addition, with the destruction of coconut trees, the supply of commonly used coconut husk became difficult. The present work has focused on the development of alternative media to coconut husk and on the development of cultural and fertilizer practices that increase plant productivity and reduce incidence of disease. The variety Honduras was chosen for the study. A 3 × 3 latin square design was used to evaluate four media—coconut husk, brick chips, gravel, and basalt igneous rock—two methods of cultivation—pots and beds; at three levels of fertilizer—244, 448 and 896 kg N/ha per year. While the coconut husk was still the better medium, the other media have resulted only in about 15% decline in the marketable blooms. This was offset by the requirement for low maintenance and lower fertilizer rates in inorganic media compared to coconut husk. Pot culture proved to be better for management purposes as well as production for the same area of production, as density of the plants could be increased and the incidence of disease could be easily managed. These results will be discussed with emphasis on a simple cost–benefit analysis of various combinations of cultivation methods and practices for commercial cultivation of A. andreanum var. Honduras in the Caribbean.
382 The Southwest Ohio Fruit and Vegetable School—A Successful Multi-county Program
Authors: Gao Gary
Published: February 2019

Southwest Ohio Fruit and Vegetable School is a regional training program for both commercial growers and amateur gardeners. The program has been sponsored by four county Extension offices in Southwest Ohio and has attracted a total attendance of 571 since 1995. We have offered two concurrent sessions, one for commercial fruit and vegetable growers, and one for amateur gardeners. This combination has proven to be the key factor in the success of the program. Attendees are allowed to move between the commercial and amateur sessions. Many commercial growers brought their spouses along since there were good topics for both of them. Backyard gardeners benefitted from the commercial session since the information was very applicable to their situation. Commercial growers also receive their pesticide recertification credits. Some of the popular topics for the commercial session included: management of diseases, insects, and weeds of fruits and vegetables; production of fresh market tomatoes, green beans, peppers, sweet corn, and pumpkins; production of herbs and specialty crops; production of apples, raspberries, strawberries, and blueberries. Popular topics for the non-commercial session included: growing tree fruits and small fruits in home gardens; raised bed gardening; growing giant pumpkins; nuisance wildlife damage control; growing and using culinary herbs; beneficial insects; and managing garden pests without using conventional insecticides. The Southwest Ohio Fruit and Vegetable School has been a very successful training program and could serve as a good model for other county Extension educators.
384 PLANT: Purdue Landscape and Nursery Thesaurus—An Internet Database for Commercial Landscape Horticulture
Authors: Moser Bruno C.
Published: February 2019

Information on the Internet relative to the landscape and nursery industries is rapidly expanding. However, finding reliable sites on subjects of interest to the field of commercial landscape horticulture is a difficult task. PLANT: Purdue Landscape and Nursery Thesaurus, is an extensive database of links to Internet information for professional landscape contractors/managers and nursery growers in Midwest and Northeast states. PLANT currently consists of 21 independent pages on topics from “Computer Software” to “Winter Hardiness”, with >2500 links to appropriate Internet information. A search mode allows one to search the database by key words as well. This extension-based tool is also an excellent resource for class assignments in the area of ornamentals and landscape horticulture. As a work in process, PLANT is regularly updated and expanded to provide multiple sources if Internet information on topics of interest to the landscape and nursery industries. PLANT can be found at bluestem.hort.purdue.edu/plant/.
389 Evaluation of Activators for Composting
Authors: Barker Allen V.
Published: February 2019

Activators are suggested as adjuvants to accelerate rates of composting of plant residues. Three activators, two microbial preparations and one enzyme-based material, were assessed. The feedstock for composting was a 1:1 volumetric ratio of vegetative food wastes and autumn leaves from broadleaf trees. Composting was conducted in 0.35-m3, covered, plastic bins. In one experiment, the bins were filled to capacity twice, once at treatment initiation and at 1 week later. Treatments included no activator, an addition of each microbial preparation individually, addition of the enzyme-based activator individually, and additions of one of the microbial preparations and the enzyme-based activator in combination. The individual applications were at full-strength according to recommendations on the labels, and the combinations were at full-strength or at half-strength according to the recommendations. Piles in the bins were turned weekly, and activators were added weekly or only once according to the manufacturers' recommendations. Composting proceeded for 60 days. In a second experiment, the same protocols were followed with the modification that feedstock was added to each bin weekly for 60 days, followed by a 30-day curing period. Temperatures of the compost were recorded weekly. Piles were moistened weekly after turning. None of the activators accelerated the rate of composting relative to the rate with no activators. Rate of composting was evaluated by comparison of the weekly temperatures of the piles, the volume of compost produced, and the texture of the compost. Tomato (Lycopersicon esculentum Mill.) plants grew equally well in composts from each of the treatments. The conclusion was that compost activators did not modify the process or quality of compost produced from food and tree-leaf residues.
392 Barriers and Incentives for Consumers' Adoption of Landscape Practices Recommended by the “Florida Yards and Neighborhoods” Extension Program
Authors: Brown Sydney Park , Knox Gary W.
Published: February 2019

A random sample was made from 2000 Extension customers who had attended programs on Environmental Landscape Management within 17 counties in Florida. Four-hundred Master Gardeners and 500 other citizens were sent a questionnaire that gathered information on demographics as well as six landscape practices. Incentives and barriers to practice adoption were also examined. The return rate of the questionnaires was 83%. Results of the analysis and their implication for Extension programming will be presented.
393 The University of Kentucky Home Landscape IPM Program
Authors: Durham Richard E. , Hartman John R. , Johnson Monte P.
Published: February 2019

A home landscape integrated pest management (IPM) extension program has been initiated in the Univ. of Kentucky College of Agriculture. In order for this program to be effective, activities must integrate aspects of general landscape management with pest management. The main tenets of the project encompass four areas: making wise choices when selecting plants for the landscape; practicing proper planting and transplanting techniques; maintaining the health of the plant in the landscape using proper watering, fertilizing, and pruning techniques; and practicing an integrated approach to managing pests in the landscape. Outreach mechanisms for this project include the preparation and broadcast of radio scripts, the production of educational videos for use by county agents, print material, and addition of a home landscape IPM section to the Univ. of Kentucky IPM web page. Examples of these activities will be presented. The initial emphasis of the program is on woody landscape plants; however, other areas of landscape management, including annuals and perennials, turf, and home fruit and vegetables, will be added as time and funding allow. This outreach program may be the first exposure many people have to IPM principles and thus it will play an important roll in educating the public to integrated pest management practices that are a vital part of modern agriculture production.
395 Rock Gardening in Oklahoma
Authors: Owens D. Steve , Schnelle Michael A. , Dole John M.
Published: February 2019

Rock garden plants, typically alpine in nature, are indigenous to higher elevations and thus perform poorly in the South. Consequently, they are not adapted to environments with tight clay soils, extreme heat, high humidity, and periodic drought. A video and extension circular were produced to demonstrate the construction, planting and maintenance of an appealing yet durable rock garden for Oklahoma. Modifications in soil type, plant materials, and arrangement of rock, wherein small micro-habitats are created, comprise the core of the project. The aforementioned educational materials benefit the gardening public with previously unavailable information for Oklahoma. The video is included in the Oklahoma State Univ. Cooperative Extension Service video library, where it is available via rental or purchase. It provides informative visual instruction, complementing the written publication that outlines stepwise construction techniques coupled with a list of adaptable plants. Both the publication and video may have applications for gardeners in peripheral states.
396 Children's Gardens in Which to Learn and Grow—A Service/Learning Project
Authors: Hillock David , Kirkwood Matthew , Needham Douglas , Sanders Brenda
Published: February 2019

The purpose of a service/learning project is two-fold: to gain skill in one's area of study and simultaneously to provide service to an unrelated community. This project provided such an educational opportunity for our Horticulture and Landscape Architecture students by providing the mechanism for them to develop and practice their skills of garden design, presentation, installation, and maintenance, while also providing a service to Oklahoma's fifth grade teachers and their students. Through their service, our students gained insight into the creation of public gardens, specifically ones for children. This project created a template through which elementary educators could then work with their communities to develop children's gardens at their schools. Our students presented gardening ideas via slides to fifth grade classes, geographically distributed throughout Oklahoma, and then surveyed them for their input into a garden designed for and by children. The survey accessed the needs and dreams of both the fifth grade students and their teachers. The children's and teachers' desires, as expressed in the surveys, were incorporated into garden designs by our students. A prototype of one of the children's gardens was then installed at the Oklahoma Gardening studio grounds with the help of Horticulture and Landscape Architecture students, OBGA Ambassadors (a group of horticulturally trained volunteers from the Greater Stillwater Community), and Oklahoma elementary school teachers, who sought to gain experience in garden installation in order to create a children's garden at their own schools. The processes, from conception through design and installation, and finally utilization for elementary education, were videotaped and incorporated into a “how-to” video and fact sheet, produced and made available through the Oklahoma Cooperative Extension Service (OCES).
401 Effects of Allyl Isothiocyanate on Mycelial Growth from Germinating Sclerotia of Sclerotium rolfsii
Authors: Harvey Stephanie G. , Sams Carl E.
Published: February 2019

Isothiocyanates are volatile chemicals produced by damaged tissues of Brassica species. Allyl isothiocyanate (AITC), the predominant isothiocyanate in Indian mustard (B. juncea), has been shown to control pest in laboratory and field experiments. We investigated the effectiveness of AITC against the germination of sclerotia of Sclerotium rolfsii Saccardo, a common soilborne pathogen of tomato. Sclerotium rolfsii was cultured on PDA from a field isolate. Mature sclerotia were collected and placed in polyester mesh bags. Culture tubes (16 × 150 mm) were packed with 18 g clay loam soil. A sclerotia-bag was placed in each tube and covered with an additional 5 g soil. Soil was maintained at 60% field capacity for the duration of the experiment. AITC was injected into each tube through a septum. Treatments consisted of 0, 5.6, 11.2, 22.4, and 44.8 μmol AITC/L of atmosphere and an ethanol control. AITC in each tube was sampled using SPME and analyzed on GC-MS. Tubes remained sealed for 42 h at 30 °C. Sclerotia were then removed from tubes and bags and plated on PDA to determine viability. Radial growth was measured to determine the effects of AITC. Mycelial growth was negatively correlated to AITC concentration (P < 0.01). The highest concentration of AITC resulted in a 40.3% reduction in mycelial growth. Although the AITC concentrations used in this study did not kill sclerotia of S. rolfsii, they did suppress mycelial growth from germinating sclerotia. At higher concentrations, or mixed with other chemicals, AITC may prove to be an affective control for this pathogen.
405 No-till Vegetable Production in the Sand Hill Region of North Carolina
Authors: Hoyt Greg D.
Published: February 2019

An experiment was established to determine the effect of different winter cover crops residues on yields of no-till pumpkins, yellow summer squash, and sweet corn. Residue treatments of fallow, triticale, crimson clover, little barley, and crimson clover + little barley were fall established and killed before spring no-till planting in 1998 and 1999. All summer vegetables received recommended fertilizer rates and labeled pesticides. Spring cover crop growth and biomass measurements ranged from 1873 to 6362 kg/ha. No-till sweet corn yields among the various cover residue treatments were greater where crimson clover and crimson clover + little barley (mixture) were used as residue in 1999, but not significantly different in 1998. No-till pumpkins showed the beneficial affect cover crop residue had on vegetable yields when dry conditions exist. Triticale and crimson clover + little barley (mixture) residues reduced soil water evaporation and produced more numbers of fruit per hectare (5049 and 5214, respectively) and greater weights of fruit (20.8 and 20.9 Mg/ha) than the other residue treatments (3725 to 4221 fruit/ha and 11.8 to 16.1 Mg/ha, respectively). No-till summer squash harvest showed steady increases in yield through time by all treatments with crimson clover residue treatment with the greatest squash yields and triticale and little barley residue treatments with the lowest squash yields. We found that sweet corn and squash yields were greater where legume cover residues were used compared to grass cover residues, whereas, pumpkin yields were higher where the greatest quantity of mulch was present at harvest (grass residues).
406 Plant Diversity Influences Effectiveness of Associated Arbuscular–Mycorrhizal Fungi
Authors: Burrows Rhoda , Pfleger Francis
Published: February 2019

Growing a plant host in association with other plant species (i.e., increasing diversity) changes the composition of the associated arbuscular–mycorrhizal (AM) fungal community. We tested whether this alteration in the fungal community causes significant differences in the growth of Schizachyrium scoparium L. (Little Bluestem, a C4 grass) or Lespedeza capitata L. (Bush clover, a legume). Seedlings were transplanted into pasteurized soil inoculated with soil from monoculture plots of Schizachyrium or Lespedeza, respectively, vs. plots containing one, seven, or 15 additional plant species. Soil washes from a composite of the plots were added to all pots, including non-inoculated controls, to reduce differences in the non-AM microbial communities. Spore counts of the inoculum from Lespedeza plots showed increasing numbers of AM fungal spores and species richness with increasing plant diversity; this was not true with the Schizachyrium plots, possibly because Schizachyrium may be a better host to more species of AM fungi than Lespedeza. Both Schizachyrium and Lespedeza responded to inoculation with increased growth compared to non-inoculated controls. Tissue analyses of both species showed that inoculation increased the percentage of Cu, and lowered the percentage of Mn compared to control plants. Schizachyrium showed no significant differences in growth due to inoculum source (1-, 2-, 8-, or 16-species plots); while Lespedeza showed increases in root and shoot weights with increasing source-plot diversity.
410 Biologically Based Weed Control in Strawberry
Authors: Hoover Emily E. , Forcella Frank , Hansen Neil , Poppe Steve , Propsom Faye
Published: February 2019

Lack of effective weed control is the major limiting factor in strawberry production. With few herbicides labeled for use in this perennial crop, weeds are controlled using manual labor, cultivation, and one or two herbicide applications. However, these practices do not provide long-term, effective weed control, and weeds continue to be the number one reason why strawberry fields are removed from production due to a reduction in yield. The objective of this study was to evaluate weed control during strawberry plant establishment using woven woolen mats and spring-sown canola. The effects of these mulches on weed control and strawberry plant production were studied independently and in tandem. Weed and daughter plant counts were compared among treatments to test for differences. Wool mulch, both single- and two-ply, was an effective barrier to weeds within the strawberry rows. Planting canola between rows or broadcasting in combination with the wool mulch decreased the number of weeds when compared to other treatments. The four treatments that included wool had the highest number of rooted daughter plants when compared to all the other treatments except the weed-free plot. The canola treatments without wool mulch did not produce as many rooted daughter plants and were not statistically different from the weedy-check.
415 A Distance Learning Website for Teaching Vegetable Crops at Virginia Tech
Authors: Welbaum Gregory E.
Published: February 2019

A distance learning homepage at: http://www.bsi.vt.edu/welbaum/hort4764/ was created to teach an introductory college-level course on vegetable crops to students at Virginia Tech. The course was created to serve students in the horticulture program at Virginia Beach, Va., students in the Commonwealth who cannot take classes on the Blacksburg campus, and students on the Blacksburg campus who could not schedule the classroom-based course. The course is not selfpaced, but directs students through 44 lessons on various topics including detailed descriptions of 28 different vegetables. The site is primarily in HTML format with archived student projects and old exams in PDF format. Audio clips are used to emphasis key information and to add a personal touch. There are >550 pictures and descriptions of vegetables and vegetable crop production linked to the website. Students can be examined using a computer testing system call Whizquiz that grades and corrects each exam. “Web Forum” software enables online discussion among students and the instructor. Discussion sessions have been successfully conducted between students and guests at distant locations. Links are provided to over 25 other websites with information on vegetable crops. The project was funded by a USDA/CSREES Higher Education Challenge Grant.
417 The Development of Virtual Campus Plant Walks to Aid in the Learning of Ornamental Plants
Authors: Mason Kimberly A. , Brand Mark H.
Published: February 2019

The Univ. of Connecticut has designed a website that will help facilitate the learning of landscape plant material. The main objective of this site is to help students taking plant identification courses in New England's land-grant universities and one private college. Virtual Campus Plant Walks have been developed to address budget constraints, student demands for technology integration in the classroom and to make use of the pedagogical benefits of the internet medium. The Virtual Campus Plant Walks are on-line walks that have detailed pictures and information given during actual plant walks done in each plant identification laboratory. Students are able to retake the walks at their own pace, reevaluate a plant they are having trouble remembering, or take the walk over the internet for the first time if they were unable to attend lab. Students will now be able to study plant material whenever they want, regardless of the time of day or weather. The educational validity of the walks has been tested for three semesters and the results are favorable. Surveys reveal that 80% believe the website improved their grades and 76% claimed the website decreased their study time. This evidence will promote the continued and expanded use of the website.
419 A Laboratory Demonstration of Water Stress on Plant Growth
Authors: Buxton J.W. , Phillips T.D.
Published: February 2019

Students in plant science courses have difficulty thoroughly understanding the effect of water stress on net photosynthesis and its consequences—reduced plant growth, productivity, quality, and profit. A laboratory demonstration utilizing a controlled water table irrigation system (CWT) provides a nearly constant plant water potential. Pots are placed on a capillary mat with one end suspended in a trough with nutrient solution. The vertical distance from the solution surface to the pot bottom determines the water potential; the water potential is 0 when the pot bottom is at the same level as the nutrient solution. The greater the vertical distance from solution to the pot bottom, the lower the water potential. For this demonstration, the bench was sloped from 0 to 10 cm above the solution over a distance of 90 cm. Corn, squash, soybean, fescue, and marigold seed were directly sown to either 9- or 15-cm pots and then placed on the CWT sloped bench at five vertical distances above the solution. Weekly, students observed plant growth and at the end of 8 weeks evaluated root and shoot growth. For all species, plant growth was indirectly related to the distance above the nutrient solution. Plants at near 0 water potential were much larger than those grown 8 to 10 cm above the solution.