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  • Author or Editor: Dewayne L. Ingram x
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The contributions of interrelated production system components of a field-grown, 2-m-tall, 5-cm-caliper Picea pungens (colorado blue spruce) in the upper midwestern (liner) and lower midwestern (finished tree) regions of the United States to its carbon footprint were analyzed using life cycle assessment protocols. The seed-to-landscape carbon footprint was 13.558 kg carbon dioxide equivalent (CO2e), including sequestration of 9.14 kg CO2e during production. The global warming potential (GWP) from equipment use was the dominant contributor to the carbon footprint of production. Seventy-six percent of the GWP investments during field production occurred at harvest. Querying the model, among other things, revealed that adding one year to the field production phase would add less than 3% to the seed-to-landscape GWP of the product. The weighted positive impact of carbon (C) sequestration during a 50-year life was 593 kg CO2e. After its useful life, takedown and disposal would result in emissions of 148 kg CO2e, resulting in a net positive, life cycle impact on atmospheric CO2 of ≈431 kg CO2e.

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The University of Kentucky's Department of Horticulture, led by the extension faculty working with targeted industry associations, facilitated the creation of the Kentucky Horticulture Council to be the voice of a diverse industry. Leadership in industry strategic planning, promoting the opportunities for expansion of the horticulture industry, and educating state agriculture, legislative and university leaders provided a focus of energy and positioned the industry to access emerging resources. Leadership development has been an anticipated byproduct of this process.

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Abstract

Excised roots of Pittosporum tobira Thunb. were exposed to temperatures of 25° to 60°C for 30 to 300 min before cell membrane thermostability was determined by electrolyte leakage procedures. Response to treatment temperature for each exposure duration was sigmoidal. The critical temperature causing injury to root cell membranes decreased linearily as exposure duration increased exponentially. A mathematical model to describe the interaction of treatment temperature and exposure duration on membrane thermostability is presented.

Open Access

Abstract

The thermostability of Ilex crenata Thunb. ‘Helleri’ and Ilex vomitoria Ait. ‘Schellings’ root cell membranes at supraoptimal temperatures were determined using electrolyte leakage procedures with excised roots. Mathematical models were developed to describe effects of treatment temperature and exposure time interactions on membrane thermostability. Critical temperature, Tc, decreased linearly as exposure duration increased exponentially, and predicted Tc for ‘Helleri’ and ‘Schellings’ were 51.0 ± 0.8 and 52.6 ± 0.7°C, respectively, for a 30-min exposure and 43.9 ± 0.8 and 46.7 ± 0.3° for a 300-min exposure. Three dimensional plots of the fitted mathematical functions are presented.

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Abstract

White polyethylene bags were superior to black, 6 liter conventional containers for production of Cornus florida L., Rhododendron simsii Planch, cv. Formosa and Pittosporum tobira Banks in full sun. All 3 species grew best in 47% shade, where effects of container design were moderated Poly bags were brittle within 6 months in full sun and could not withstand rough handling.

Open Access

This presentation focuses on driving forces and philosophies in the current Age of Accountability and explores ideas of how to respond. The increased scrutiny faced by all public agencies is requiring that Cooperative Extension approach the issue of accountability a bit differently. We must articulate our objectives and values to specific clientele groups, the general public, and government officials. Hard questions are being asked about past and anticipated return on tax dollars invested in state and federal agencies. The Government Performance and Results Act of 1993 requires “performance based budgeting” for all federal agencies, including the USDA. Each federal agency must develop an action plan with well-defined objectives and anticipated impacts to justify the allocation of federal funds. The overriding theme is not how busy we are and how many activities we can report, but what has been the impact of our efforts.

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Abstract

This symposium was sponsored primarily by the Commercial Horticulture Working Group in the Extension Division of ASHS. The International Horticultural Congress provides an excellent opportunity for horticulturists, especially horticultural educators, from around the world to exchange experiences and ideas. Extension in the context of this symposium refers to the transfer of technology or the linkage from a research-based information pool to producers, processors, marketers, and consumers of horticultural commodities. Extension programs are expected to help ensure the adoption of appropriate technologies by individuals, groups, or segments of an industry. The primary goals of an extension program are to increase production, product quality, business profits, and/or the quality of life. This symposium involved uniquely qualified individuals in describing and contrasting model extension delivery systems from around the world.

Open Access

Previously published life cycle assessment (LCA) studies regarding the global warming potential (GWP) of tree production have shown that the carbon footprint during the cradle-to-grave life cycle of a tree can reduce atmospheric CO2. This study provides another unique contribution to the literature by considering other potential midpoint environmental impacts such as ozone depletion, smog, acidification, eutrophication, carcinogenic or non-carcinogenic human toxicity, respiratory effects, ecotoxicity, and fossil fuel depletion for 5-cm-caliper, field-grown, spade-dug trees. Findings from this study validate using data from various literature sources with a single-impact focus on GWP and compiled and calculated in a spreadsheet or using a LCA software package with embedded databases (SimaPro) to generate comparable GWP estimates. Therefore, it is appropriate to use SimaPro to generate midpoint environmental impact estimates in LCA studies of field-grown trees. The authors also compared the midpoint environmental impacts with other agricultural commodities [corn (Zea mays), soybean (Glycine max), potato (Solanum tuberosum), and wool] and determined that trees compare favorably, with the exception that fossil fuel depletion for the trees was greater than the other products as a result of the high equipment use in harvesting and handling trees. In addition, the water footprint (WF) associated with tree production is also determined through LCA using the Hoekstra water scarcity method in SimaPro. The propagation-to-gate WF for the three tree production systems ranged from 0.09 to 0.64 m3 per tree and was highly influenced by irrigation water, which was the major contributor to WF for each production system. As expected, the propagation stage of each tree represented significantly less WF than the field production phase with larger plants and lower planting densities, even with more frequent irrigation/misting in liner production.

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Plants of `Rotundifolia' holly (Ilex crenata Thunb.) were grown for 3 weeks with root zones at 30,34,38, or 42C for 6 hours daily to evaluate the effects of supraoptimal root-zone temperatures on various photosynthetic processes. After 3 weeks, photosynthesis of plants grown with root zones at 38 or 42C was below that of plants grown at 30 or 34C. Chlorophyll and carotenoid levels decreased while leaf soluble protein levels increased as root-zone temperature increased. Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) activity per unit protein and per unit chlorophyll responded quadratically, while RuBisCO activity per unit fresh weight increased linearly in response to increasing root-zone temperature. Results of this study suggest that `Rotundifolia' holly was capable of altering metabolism or redistributing available assimilates to maintain CO2 assimilation rates in response to increasing root-zone temperatures.

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