Browsing by Author "Eaton, Gregory K."

Now showing 1 - 12 of 12
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    Backyard wildlife habitats
    Eaton, Gregory K.; Wright, Barbara (Virginia Cooperative Extension, 2009-05-01)
    This publication describes the benefits of creating or enhancing a backyard wildlife habitat, as well as the basic needs of food, water, cover, and space to create an wildlife-friendly environment.
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    A Case Study on the Economic Feasibility of Producing Maple liners in a Traditional Tobacco Greenhouse
    Wilkerson, Joseph Edward (Virginia Tech, 2002-04-26)
    The goal of this case study was to investigate the economic feasibility of a new enterprise for Southside Virginia farmers to help alleviate problems stemming from a loss of income and excess production capacity of a tobacco greenhouse. Maple liner production in a tobacco greenhouse was determined to not be economically feasible by this study. The control scenario, as well as the sensitivity analysis revealed that maple liner production would yield a loss when produced in a tobacco greenhouse. The breakeven number of plants to be sold was 43% of the cuttings planted, and could exceed 50% under some conditions of the sensitivity analysis. While the maple liner production schedule was determined to be culturally suitable as a supplemental greenhouse activity, the tobacco greenhouse engineering design was deemed inadequate for maple liner production. Modifications were needed to the ventilation and irrigation systems. This economic study was based on a field trial conducted in Halifax County, Virginia.
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    An Economic Impact Assessment of the Green Industry of Virginia
    Coppedge, Emily Jean (Virginia Tech, 2004-06-28)
    An analysis of the green industry of Virginia was completed in the year 2002 using a mail survey sent to industry participants. The survey was conducted by the Virginia Agricultural Statistics Service (VASS). This data was used to run an economic impact analysis of the industry using IMPLAN Professional software. Additionally, the software was used to determine the approximate affects of drought and water restrictions on the green industry. VASS received a total of 1,146 surveys for a response rate of approximately 27%. Of these responses, 42 surveys indicated that they plan to have future green industry sales but were not presently involved in the business. Another 525 responses claimed to be no longer actively involved in the industry. Therefore, the actual response rate was much closer to 15%. This necessitated the use of numerous alternative data sources to create a more complete model representation of the green industry as a whole. Two separate model scenarios were created, the first using purely survey response data, the second including data from additional sources and factoring out for possible double-counting errors. Direct employment generated from the industry was predicted to be between 29 and 36 thousand jobs, depending on which model scenario is consulted. The total economic impacts predicted from the different models are $2.03 billion and $2.41 billion, respectively. The analysis of the affects of drought and water restrictions predicted a decrease in overall impacts by 33% and 23%, respectively.
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    Getting Started in the Nursery Business: Nursery Production Options
    Eaton, Gregory K.; Appleton, Bonnie L. (Virginia Cooperative Extension, 2009-05-01)
    Summarizes factors, such as nursery design and capitalization, that individuals in Virginia's nursery industry should consider when deciding whether to grow nursery stock in the field verses containers.
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    Oxalic acid production by the ectomycorrhizal fungus Hebeloma westraliensis and its role in the nutrient acquisition and growth of Eucalyptus diversicolor in calcareous soil
    Eaton, Gregory K. (Virginia Tech, 1994-12-05)
    This work includes an introduction and literature review of mycorrhizal enhancement of the mineral nutrition of host plants. Particular attention was paid to the role of mycorrhizae in acquiring P from inorganic phosphates. Two experiments were designed to study a mechanism by which the ectomycorrhizal fungus Hebeloma westraliensis can enhance the availability and absorption of P from Ca phosphate by Eucalyptus diversicolor in calcareous soil. Chapter 2 reports on a study on the growth and oxalic acid production of H. westraliensis in calcareous and noncalcareous liquid media. Oxalic acid is thought to chelate cations from phosphate precipitates allowing the release of phosphate into solution. L-threonine was added as an additional treatment to asses the ability of this amino acid to inhibit oxalic acid production by the fungus. Growth and oxalic acid production of H. westraliensis were increased in the calcareous systems. L-threonine had little effect on dry weight of mycelium but substantially reduced oxalic acid production in the calcareous media. Chapter 3 reports on a study of E. diversicolor X H. westraliensis mycorrhizal synthesis in model calcareous and noncalcareous systems. Oxalic acid production was measured in these systems as well as various measurements of solution and host plant nutrition. Solution P concentration decreased and solution Ca increased in the calcareous systems. Mycorrhization decreased the solution concentrations of both of these nutrient elements, due partly to sequestration of these elements in fungal and plant tissues. Plant tissue P concentration was decreased and tissue Ca concentration increased in the calcareous systems. Mycorrhization increased the concentrations of both of these elements in plant tissues. Mycorrhization also increased the height and dry weight of seedlings at harvest and ameliorated symptoms of nutrient deficiencies seen in nonmycorrhizal plants in the calcareous system. Oxalic acid production by the fungus and by the plant were increased in the calcareous system. Attempts to correlate oxalic acid production with solution and plant nutrition were unsuccessful. The relationships of these results to the mycorrhizal enhancement of plant nutrition in calcareous soil is discussed.
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    Plasticity and constraint in growth and protein mineralization of ectomycorrhizal fungi under simulated nitrogen deposition
    Eaton, Gregory K.; Ayres, Matthew P. (Mycological Society of America, 2002)
    Ectomycorrhizal fungi allow their host plants access to organic forms of N through enzymatic mineralization of the substrate and enhanced absorption of amino acids and mineral N. The cost to the plant is carbohydrates that support fungal growth and metabolism. Enrichment of soils with mineral N, as through atmospheric deposition, may affect the growth and function of these fungi by direct effects of increased N availability on fungi and indirect effects through reduced plant C allocation to roots. We tested the potential of N enrichment and altered carbohydrate supply to affect the growth and protein mineralization activity of 10 ectomycorrhizal fungi in sterile liquid media. Nitrogen treatments consisted of organic N only vs organic plus mineral N. Carbon treatments consisted of 5 g per liter glucose vs. no glucose added. Fungi differed widely in their growth and mineralization responses to these variables. Seven of 10 fungi had at least 20% reduced growth with reduced carbohydrates. Only 2 of 10 increased growth by 20% or more with increased mineral N. Carbohydrates affected growth more in a purely organic N environment suggesting an energy limitation to mineralization. Protein mineralization activity tended to be depressed by reductions in carbohydrates and increased by increased mineral N. The high sensitivity of fungal growth to carbohydrates suggests important indirect effects of N enrichment via altered C allocation in host trees. Principal Components analysis separated most fungal species along an axis representing a gradient from high protein mineralization efficiency to high intrinsic growth rate. Those fungi with slow growth and efficient mineralization activity corresponded closely to fungi often cited as late successional species, while fungi with high growth rates and low mineralization efficiency are often categorized as early successional. One fungus, Cenococcum geophillum, separated from others on an axis representing strong N dependence in growth. Nitrogen enrichment has the potential to alter the composition and function of the ectomycorrhizal fungus community. Physiological differences among species provide a starting point for predicting community responses and anticipating ecosystem consequences.
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    Quantifying the Potential for Non-Point Source Pollution in Model Urban Landscapes
    Wolyniak, Brian John (Virginia Tech, 2005-08-25)
    The contribution of non-point source pollution to degrading surface water quality is considerable throughout Virginia and beyond. While research on agricultural best management practices in nutrient management and nutrient and soil stabilization has made progress in reducing agricultural contributions to nutrient and sediment loading of watersheds, little is known about how land covers of different vegetation representative of urban areas (e.g., bare soil versus turfgrass lawns versus urban forest) influence the potential for non-point source pollution. Ambient rainfall volumes were manipulated to provide 50%, 100%, and 150% of natural precipitation to plots with landscape covers of bare soil, shredded wood mulch, turfgrass, and simulated urban forest (complete pin oak canopy with shredded hardwood leaf mulch). Precipitation amounts, runoff volumes, and eroded sediment masses for ten rain events between July and December 2004 were measured. Runoff was analyzed for nitrate and orthophosphate concentrations for three rain events. Turfgrass was found to be the most effective of the land covers tested at reducing components of non-point source pollution from stormwater. Turfgrass plots produced, on average, the least runoff and sediment, and lower nitrate concentrations in runoff water as compared to the other land covers tested. Results from urban forest plots apparently reflected the disturbance of tree planting, even six months later. This study contributes to a sparse body of knowledge about the influences of urban landscapes on water quality, and will inform land use policy and urban Best Management Practices.
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    Recycling Aquacultural Waste through Horticultural Greenhouse Production as a Resource Recovery Approach
    Nair, Divya Sreelatha (Virginia Tech, 2006-02-10)
    For intensive production systems like the Blue Ridge Aquaculture (BRA), based in Martinsville, VA, there are significant economic incentives to reuse the waste by diverting it into a cropping system that would increase the total productivity and total resource-reuse efficiency, and decrease the environmental, ecological, and financial costs of aquacultural waste disposal. In order to facilitate the reuse of effluent from the tilapia production at the BRA, a green house was developed. On this site, sludge waste from recirculating aquaculture was separated and composted using a vermicomposting technique and the resulting compost was utilized as an amendment to conventional greenhouse potting mixes. These aquacultural waste products were compared to conventional greenhouse culture of a common ornamental annual plant. It was hypothesized that (1) vermicomposted aquaculture sludge would increase the growth of plants over conventional greenhouse potting mixes, and (2) recycled aquacultural wastewater can serve as a quality source of irrigation water, and plant response would differ with irrigation method. Plant growth and 11 out of 12 plant tissue nutrients were greater when compost was increased in the substrate. Plant root growth and 3 out of 12 tissue nutrients were increased when irrigated with wastewater. Plant shoot mass and total mass was greater when irrigated by ebb and flow irrigation compared to overhead mist irrigation, and 4 out of 12 tissue nutrients were greater when irrigated with mist irrigation. Overall plant performance was greatest with 15% vermicomposted sludge in the substrate and watered with wastewater by ebb and flow irrigation.
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    Resources for Greenhouse and Nursery Operations and Operators
    Latimer, Joyce G.; Eaton, Gregory K. (Virginia Cooperative Extension, 2009-07-01)
    A list of resources for a greenhouse or nursery business, including suppliers, education, pest control, organizations, reference books, and more.
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    Trees and Shrubs for Acid Soils
    Appleton, Bonnie L.; Heins, Robert; Donohue, Stephen J.; Eaton, Gregory K.; Alleman, Dawn (Virginia Cooperative Extension, 2009-05-01)
    This publication reviews the planting guidelines for trees and shrubs for acid soils including plant and site selection, site preparation, tree and shrub preparation, and tree care and planting.
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    Trees for Parking Lots and Paved Areas
    Appleton, Bonnie L.; Horsley, Jack; Harris, Vivian; Eaton, Gregory K.; Fox, Laurie J.; Orband, James; Hoysa, Chuck (Virginia Cooperative Extension, 2009-05-01)
    Landscaping in and around parking lots and pavement improves appearance, prevents soil erosion, and reduces carbon dioxide through photosynthesis. Planted areas also reduce storm water drainage problems, reduce the detrimental effects of wind and noise, and enhance human comfort by providing heat-reducing shade.
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    Use of Plant Growth Regulators to Increase Branching of Clematis Spp.
    Puglisi, Sadie Erica (Virginia Tech, 2002-07-24)
    Clematis spp. L. is a twining vine covered in showy blooms. Typical growth of hybrids is from the main leader, producing a thin, unbranched plant with one cyme. Apical dominance is released by cutting back the vine during production. Cutting back, or pinching, of a plant is labor intensive and compromises bloom for vegetative growth at time of sales. The purpose of this project was to eliminate manual pinching by treating young plants with chemical plant growth regulators (PGRs) that enhance branching without removal of the apical meristem. The first project evaluated the use of Atrimmec (dikegulac sodium), Fascination (BA+GA4+7), Florel (ethephon), and Dropp 50 (thidiazuron) on Clematis cultivars Ernest Markham, and Hagley Hybrid, and Clematis viticella 'Polish Spirit.' Plants treated with 800 mg·L-1 Atrimmec, or 800 or 1200 mg·L-1 Fascination experienced an increase in branch numbers. The second experiment manipulated the ratio of the components of Fascination, 6-BA and GA4+7, to reduce phytotoxicity experienced in the first experiment. The optimal ratio to enhance branching was 1:1, which is the stock solution for Fascination. All ratios produced phytotoxic symptoms. A third experiment tested lower rates of thidiazuron and added CPPU (forchlorfenuron) to the list of PGRs to test. The last experiment took the most effective PGR treatments, Atrimmec at 800 mg·L-1, and Fascination at 800 or 1200 mg·L-1, and compared them to the current production practices of pinching. Large flowering cultivars of clematis were used, including 'Comotesse de Bouchard,' 'Ernest Markham,' and 'Hagley Hybrid.' Atrimmec increased branch numbers and suppressed leader lengths without a mechanical pinch. Results from Fascination varied by cultivar.