Digital Commons Network^™

Bee Visitation To Crops And Other Flowers Planted As Bee Food, Michael Edward Wilson

Masters Theses

Farms that require insect pollination and reside in diverse landscapes benefit from pollination by native bees. However, populations of native bees and honey bees are generally in decline and this threatens food production. Documentation of crop pollination as an ecosystem service is needed to identify potential impacts from declining bee populations. This study identifies communities of bees providing pollination and how they vary across different crops and environmental conditions. Managing landscapes to provide additional food sources for bees may improve the health of wild and managed bees. This study also evaluated the attractiveness of bees to selected species of plants …

Impact Of Switchgrass Bioenergy Feedstock Production On Soil Carbon Dioxide Flux And Below Ground Soil Organic Carbon Storage In East Tennessee, Leah Denise Soro

Masters Theses

Bioenergy production from switchgrass has shown promise in restoring degraded soils and helping to mitigate greenhouse gas (GHG) emissions. CO₂ loss and C-sequestration in soils are important topics for research to better understand the environmental impacts of bioenergy crops. The need for more thorough research of the carbon cycle in soils used for bioenergy production precipitated the primary interest of this study. The specific objectives of this study were 1) to measure SOC under switchgrass production in order to predict storage of carbon in soils based on previous cropping history, land management, soil physical characteristics, and time; and to …

Identifying Pathogens Of Switchgrass And Investigating Antimicrobial Activity Of Switchgrass-Derived Extractives, Andrea Linh Vu

Masters Theses

Switchgrass is an increasingly important biofuel crop, but knowledge of switchgrass fungal pathogens is not extensive. The purpose of this research was to identify the fungal pathogens that decrease crop yield of switchgrass grown in Tennessee and to investigate a potential value-added by-product of the switchgrass biofuel conversion process. The specific objectives were 1) to identify and characterize prevalent fungal pathogens of switchgrass in Tennessee, 2) assess switchgrass seed produced in the United States for seedborne fungal pathogens, and 3) evaluate switchgrass extractives for antimicrobial activity against plant pathogens.

Diseased switchgrass samples were collected from several locations in East Tennessee. …

Influence Of Timing Of Prescribed Burn On Native-Warm Season Grass Forage Quality In Tennessee, Amanda L. Mathenia

Masters Theses

Native warm-season grass stands have the prospective to provide nutritious summer forage in grazing systems. The study examined the influence of timing of prescribed burn on native warm-season grass stands in Tennessee. The purpose of the study was to determine the nutritional quality of forage as it relates to the timing of prescribed burns on native warm-season grass stands in Tennessee. The prescribed burns were conducted in March, April, May, and September. Forage samples were collected at Ames Plantation, West Tennessee Research and Education Center, Bridgestone/Firestone Wildlife Management Area, and Yuchi Wildlife Management Area. These samples were then analyzed for …

Integrated Strategies For Controlling Warm-Season Turfgrass Weeds, Matthew Thomas Elmore

Masters Theses

Herbicidal inhibitors of 4-hydroxyphenylpyruvate dioxygenase (HPPD) such as mesotrione, topramezone and tembotrione were evaluated in greenhouse experiments for activity against bermudagrass. While topramezone and tembotrione exhibited greater activity than mesotrione, none of these herbicides provided acceptable bermudagrass control. These herbicides reduced leaf tissue chlorophyll and carotenoid pigment concentrations in bermudagrass. Changes in turfgrass pigmentation were quantified using HPLC analogy as well as evaluations of visual bleaching and measurements of chlorophyll fluorescence yield (F_v/F_m). Results indicated that these more expeditious methods of evaluating HPPD-inhibiting herbicide activity (visual evaluations and F_v/F_m) cannot be used …

Development Of An Environmental Monitoring System For Greenhouse Disease Management, Crystal Marie Kelly

Masters Theses

A commercial African violet (Saintpaulia ionantha) grower experiences yield loss due to a leaf spot disease known as Corynespora casssiicola. Spotted leaves make the plants unmarketable. Outbreaks of the disease are costly and difficult to prevent. Greenhouse monitoring systems currently available on the commercial market do not have sufficient spatial or temporal resolution to be able to correlate the environmental conditions of the greenhouse with disease outbreaks. A new system was designed specifically to monitor for disease favorable conditions. The system developed for this project consists of several sensor stations and a coordinator station. The coordinator station …

Evaluation Of An Intensive Data Collection System For Tennessee Surface Water Quality Assessment And Watershed Model Calibration, Hannah Marie Armstrong

Masters Theses

Water quality regulators, such as the Tennessee Department of Environment and Conservation, are challenged by data scarcity when identifying surface water quality impairment causes and pollutant sources. Surface water quality model users also seek to identify pollutant sources and design and place best management practices to efficiently improve water quality, but have insufficient data for model calibration. This research documents the design and evaluation of a novel, intensive water quality data collection system consisting of a automatic sampler, bi-weekly grab sampling, and a long term deployment sonde. System design characteristics that were emphasized included a focus on gathering data for …

Depolymerization Of Chitosan By High-Pressure Homogenization And The Effect On Antimicrobial Properties, Deidra Shannon Lyons

Masters Theses

The focus of this study was to look at relationship between polydispersity caused by high pressure homogenization and molecular weight dependent antimicrobial activity of chitosan. It has been shown that chitosan has antimicrobial activity against bacteria, fungi, and viruses. Chitosan is obtained by partial de-N-acetylation of chitin which, consists of a ß 1-4 copolymer of glucosamine and N-acetylglucosamine residues. In this experiment we compared chitosan of sixteen different molecular weights after being processed through a high pressure homogenizer. Processed chitosan (420 kDa average molecular weight, 30% of acetylation) was dissolved in a 1% (v/v) acetic acid in water to a …

Establishment And Persistence Of Legumes In Switchgrass Biomass And Forage/Biomass Production Systems, Kara Spivey Warwick

Masters Theses

Switchgrass, Panicum virgatum, is being developed as an economically and ecologically sustainable biomass crop. Nitrogen is considered one of the most limiting inputs of switchgrass. Alternatives to synthetic nitrogen fertilization may be nitrogen-fixing legumes interseeded into switchgrass. The objectives of this research were: (1) develop efficient legume management strategies for switchgrass production systems, (2) evaluate and identify cool and warm-season legumes that can be grown compatibly with switchgrass, (3) determine whether switchgrass yields are increased by legume N-fixation, and (4) determine N-fixation of common (Vicia sativa) and hairy vetch (Vicia villosa).

This study examined the …

Establishing A Fall Harvest Window For Switchgrass Biomass Based On Optimum Decline Of Phosphorus And Potassium Levels In Shoots, Jennifer Kay Lane

Masters Theses

Switchgrass (Panicum virgatum) is a perennial grass that remobilizes nutrients during senescence and is being used as biomass for cellulosic ethanol production. Phosphorus (P) and potassium (K) are removed in harvested biomass and replenished through additions of fertilizer. Identifying the appropriate harvest window in a one-cut system based on the remobilization of nutrients can be economically beneficial for biomass producers. The primary objective of this research was to determine if a one-cut harvest can be executed earlier in the fall based on the remobilization of P and K from stems and leaves to crown and roots of plants. Better …

Potential For Alternative Agricultural Enterprises To Replace Tobacco: Burley Producers Perceptions, Maria Paula Mendieta Umana

Masters Theses

Demand for domestic tobacco has decreased over the past two decades. In 2004, the tobacco buyout program terminated marketing quotas and price support established under the federal tobacco program in 1938. Additionally, in 2003, the World Health Organization Framework Convention on Tobacco Control (WTO FCTC) acknowledged the importance of supply control in conjunction with demand control strategies to eliminate or reduce the consumption of tobacco products. According to the Census of Agriculture, the number of tobacco farms in the US fell by 40 percent between 2002 and 2007. Tobacco farmers are looking for alternative on-farm and off-farm sources of income. …

Evaluation Of Capital Investment And Cash Flows For Alternative Switchgrass Feedstock Supply Chain Configurations, Jie Chen

Masters Theses

Biofuels have been widely recognized as a potential renewable energy source, and the United States’ government has been interested in producing ethanol from lignocellulosic biomass such as switchgrass. To evaluate whether lignocellulosic biomass based biofuels production is economically feasible, this paper estimated the capital investment outlays, operation costs, and net present value for investment in alternative switchgrass feedstock supply chain configurations in East Tennessee a 25 million gallon per year ethanol biorefinery. Two scenarios are analyzed in the study. The conventional hay harvest scenario includes the production, harvest, storage and transportation of biomass feedstocks from the fields to the biorefinery. …

Knowledge And Perceptions Of Agriculture In Tennessee Through Fall Agritourism Experiences, Jessica Jarrell Poore

Masters Theses

The purpose of this study was to identify the key educational components of agritourism in Tennessee. The study strived to identify if knowledge of the agricultural industry increased due to agritourism experiences and if perception of the agriculture industry changed due to the experience. Additionally, the research sought to describe visitor demographics and characteristics.Following a pilot study in 2009, three agritourism venues throughout the state of Tennessee were used to collect surveys to create a pool of respondents and to identify their original knowledge of perceptions of the agriculture industry for the 2010 study. Additional data was gathered through an …

Intellectual Property And Policy Issues In Biotechnology, Amy Iver Yancey

Masters Theses

Intellectual property, particularly patents, plays a major role in innovation and discovery in biotechnology. Likewise, since the passage of the Bayh-Dole Act in 1981, patents have become an increasingly important factor in U.S. university-driven basic research, especially in the life sciences where patented technologies have transformed agriculture. Specifically, this paper looks at the potential impacts of these trends on university driven research, the university researcher, the pharmaceutical industry, and the farm sector with an emphasis on recent and pending court cases and legislation. This paper examines policy and adoptions issues in biotechnology and biomedicine in depth and touches on important …

Irrigation Plus Nitrogen Rate Effects On Hybrid Bermudagrass Hay Yield And Quality, With Preliminary Evaluation Of Ndvi, Tissue, And Soil Nitrate-N Sampling As Diagnostic Tools, Timothy Donald Carter

Masters Theses

A nitrogen fertility study with Vaughn’s hybrid bermudagrass conducted on a Crider silt loam soil (fine, silty, mixed, active, mesic Typic Paleudalfs) over three (3) years (2008-2011) at the Highland Rim Research and Education Center near Springfield, Tennessee is evaluated in this manuscript. Nitrogen applications are evaluated in both irrigated and non-irrigated plots at five (5) different application rates: 0, 56, 112, 168, and 224 kg N ha^-1. These rates are applied beginning in late April, and three (3) additional times upon harvests occurring in June, July, and August. Irrigation plots receive enough water to bring total weekly …