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Integrating Weed-Suppressive Cotton Chromosome Substitution Lines And Cover Crops For Sustainable Weed Management In Cotton Production Systems., Alyssa Lea Miller Aug 2023

Integrating Weed-Suppressive Cotton Chromosome Substitution Lines And Cover Crops For Sustainable Weed Management In Cotton Production Systems., Alyssa Lea Miller

Theses and Dissertations

Weeds pose a challenge to cotton production, and herbicides have been the primary means of control. However, there is growing concern over weed resistance to herbicides. To address this issue, we evaluated three cover crop species and six cotton accessions for weed suppression. The study found that hairy vetch, wheat, and B16 cotton CS line effectively suppressed Amaranthus species, while MNTN 4-15, B16, hairy vetch, and wheat were correlated with the highest cotton yield. Cover crops were also analyzed for chlorogenic acid content, with wheat, MNTN 4-15, and hairy vetch producing the highest amounts. The greenhouse tray study showed that …


The Effects Of Glyphosate Salts And Volatility-Reducing Agents (Vra) On Dicamba Volatility, Nicole Glenn Dec 2022

The Effects Of Glyphosate Salts And Volatility-Reducing Agents (Vra) On Dicamba Volatility, Nicole Glenn

Theses and Dissertations

Dicamba is often tank mixed with glyphosate to increase herbicidal efficacy but may contribute to off-target movement (OTM). In recent years, volatilization has become problematic for dicamba-containing herbicides, resulting in increased regulatory requirements necessitating the use of volatility-reducing agents (VRA) for application. Research was conducted in 2021 and 2022 using low tunnels in a field environment and humidomes in a greenhouse environment to further assess how glyphosate salts and VRAs affect dicamba volatility. Our data indicate that the inclusion of glyphosate to dicamba can increase dicamba volatility, depending on the glyphosate salt used. The inclusion of the evaluated VRAs will …


Characterization And Management Of Glyphosate-Resistant Junglerice, Clay M. Perkins May 2021

Characterization And Management Of Glyphosate-Resistant Junglerice, Clay M. Perkins

Doctoral Dissertations

Junglerice has become a major weed in Tennessee and across the mid-south. Glyphosate resistance and dicamba antagonism has resulted in the reported control failures and rise in prevalence. Junglerice was the most prevalent weed escape in cotton and soybean fields across Tennessee from 2018 to 2020. In all, 13% of the junglerice accessions could no longer be effectively controlled with glyphosate. Due to poor in-crop control, it has been recommended to start clean when trying to control junglerice and other grasses. Therefore, research was conducted to determine the best burndown methods utilizing dicamba, glufosinate, or paraquat. A sequential application of …


Presence Of Glyphosate In First Order Streams Associated With Rainfall Events, Julie Platz Apr 2020

Presence Of Glyphosate In First Order Streams Associated With Rainfall Events, Julie Platz

Undergraduate Honors Thesis Projects

Glyphosate is widely used in the United States and has recently been described as both mobile and persistent in soils and bodies of water. There is little research however, on the variability of glyphosate concentration in runoff based on different land use types. For this study an evaluation of samples from different land uses are used to assess glyphosate concentrations in first order streams during a runoff event. The intent was to compare three sites with a. known commercial applications, b. known lack of applications (organic), and c. assumed limited application of glyphosate. There was no significant difference in glyphosate …


Evaluation Of Insecticide Seed Treatments To Protect Rice (Oryza Sativa) Against Various Herbicides, Steven Michael Martin Dec 2017

Evaluation Of Insecticide Seed Treatments To Protect Rice (Oryza Sativa) Against Various Herbicides, Steven Michael Martin

Graduate Theses and Dissertations

The increase in herbicide-resistant weeds in Arkansas crop fields has led to the need for new herbicide modes of action for use in all crops. This need has led to the introduction of technologies that can be devastating to conventional rice crops. Field observation, noted that insecticide seed treatments used in rice could potentially reduce the effects of off-target movement of herbicides onto rice crops and possibly reduce the negative effects of some herbicides applied directly to rice. Research was conducted to determine if insecticide seed treatments could reduce the harmful effects of drift from imazethapyr and glyphosate onto conventional …


The Role Of Soil Microorganisms In The Resistance Of Giant Ragweed, Horseweed, And Common Lambsquarters To Glyphosate, Jessica Renee Schafer-Bugg Oct 2013

The Role Of Soil Microorganisms In The Resistance Of Giant Ragweed, Horseweed, And Common Lambsquarters To Glyphosate, Jessica Renee Schafer-Bugg

Open Access Dissertations

Continuous glyphosate use has contributed to an increasing number of problematic glyphosate-resistant (GR) weeds. The mechanism of resistance in many GR weeds is poorly understood, in part, due to a poor understanding of how exactly glyphosate kills a plant. In previous research, the efficacy of glyphosate was demonstrated to be strongly influenced by root invading soil-borne microorganisms. However, this interaction among plants, glyphosate, and soil microorganisms has only been studied in a number of crop plants, but not in weed species. This is surprising since the soil biotic environment has a strong impact on the activity of this important herbicide. …


Biology And Ecology Of Glyphosate-Resistant Giant Ragweed, Kabelo Segobye Jan 2013

Biology And Ecology Of Glyphosate-Resistant Giant Ragweed, Kabelo Segobye

Open Access Theses

Giant ragweed (Ambrosia trifida L.) is a competitive annual plant found in disturbed landscapes and is the most troublesome weed in Indiana and the US Corn Belt. It is one of the most common and problematic weeds in corn and soybean production. The introduction of herbicide glyphosate, N-(phosphonomethyl) glycine in early 1970's provided farmers with a better and low-cost tool to control weeds. The use of glyphosate drastically increased after the development of glyphosate resistant agronomic crops in 1996 and was use as a post-emergence selective herbicide. This led to overreliance and repeated use of glyphosate for weed control especially …


Intellectual Property And Policy Issues In Biotechnology, Amy Iver Yancey Aug 2011

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 …


Laboratory Study Of Responses Of Anuran Amphibians To Roundup¨ Exposures: Experimental Design And Role Of Sediment, Latice Fuentes Dec 2008

Laboratory Study Of Responses Of Anuran Amphibians To Roundup¨ Exposures: Experimental Design And Role Of Sediment, Latice Fuentes

All Theses

The contribution of incidental exposures of Roundup¨ herbicide to amphibian declines can be evaluated with carefully designed laboratory tests. Sensitive, sentinel species of larval anurans were exposed to two formulations: the original formulation of Roundup¨ and Roundup WeatherMax¨ in 96-hour acute, aqueous and water-sediment tests. An experimental design was developed that considered and held constant relevant laboratory conditions which produced precise, replicable data. Experimental design factors decreased variability and increased precision by considering and incorporating the following: 1) range-finding tests; 2) reference toxicity tests; 3) the relative sensitivity of the species tested; 4) differences in formulation; 5) the number of …