Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 6 of 6

Full-Text Articles in Entire DC Network

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. …


Distribution And Control Of Glyphosate-Resistant Johnsongrass (Sorghum Halepense) In Arkansas Soybean, Dennis Brent Johnson Aug 2013

Distribution And Control Of Glyphosate-Resistant Johnsongrass (Sorghum Halepense) In Arkansas Soybean, Dennis Brent Johnson

Graduate Theses and Dissertations

Johnsongrass, once the most persistent and troublesome grass weed of row crops throughout the southern U.S., has previously been confirmed resistant to the acetolactate synthase (ALS) and acetyl-coenzyme A carboxylase-inhibiting herbicides in the Midsouth and has recently evolved resistance to glyphosate in Arkansas. The goal of this research was to establish the geographical distribution of herbicide-resistant johnsongrass in Arkansas and to develop herbicide programs for controlling glyphosate-resistant johnsongrass in Arkansas soybean. Johnsongrass accessions were collected from 14 counties in the Mississippi River Delta region of Arkansas and screened for resistance to four of the most commonly used postemergence herbicides for …


Mechanisms And Variability Of Glyphosate Resistance In Amaranthus Palmeri And Ipomoea Lacunosa, Daniela Neves Ribeiro May 2013

Mechanisms And Variability Of Glyphosate Resistance In Amaranthus Palmeri And Ipomoea Lacunosa, Daniela Neves Ribeiro

Theses and Dissertations

The resistance of Palmer amaranth (PA) and the tolerance (natural resistance) of pitted morningglory (PM) to glyphosate have made these species among the most common and troublesome weeds in the southeastern U.S. since the adoption of glyphosate-resistant (GR) crops. Populations of GR PA (R1 and R2) were identified in Mississippi. The inheritance of glyphosate resistance was examined in reciprocal crosses (RC) between glyphosate-resistant (R) and -susceptible (S) parents (Female-S × Male-R, S/R, and Female-R × Male-S, R/S), and second reciprocal crosses (2RC) (Female-S/R × Male-S/R, S/R//S/R, and Female-R/S × Male-R/S, R/S//R/S). Dose-response assays resulted in 17- to 4old resistance to …


Evaluation Of Dormant-Season Herbicide Treatment Methods For Chinese Privet At Congaree National Park, Karen Vaughn May 2013

Evaluation Of Dormant-Season Herbicide Treatment Methods For Chinese Privet At Congaree National Park, Karen Vaughn

All Theses

Chinese privet (Ligustrum sinense Lour.) is a non-native invasive shrub that has become ubiquitous throughout the southeastern United States. There is a large infestation of privet at Congaree National Park in South Carolina, and the National Park Service is interested in controlling it with dormant-season foliar herbicide treatments. The primary objective of this study was to determine which combination of herbicide and applicator provides the most effective control of privet, while minimizing damage to non-target plants. Another objective was to document impacts of privet invasion on Congaree's plant communities.
Seven vegetation plots were installed in each of five large privet …


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 …


Enhancing Herbicide Efficacy On Reed Canary Grass (Phalaris Arundinacea) By Testing A Plant Growth Hormone, Application Times, And Herbicide Type, Denise Lynn Fong Jan 2013

Enhancing Herbicide Efficacy On Reed Canary Grass (Phalaris Arundinacea) By Testing A Plant Growth Hormone, Application Times, And Herbicide Type, Denise Lynn Fong

Browse all Theses and Dissertations

Phalaris arundinacea, also known as reed canary grass (RCG), is a non-native invasive grass that thrives in floodplains. RCG plants displace native flora which reduces diversity in otherwise species rich wetlands. This is a widespread problem throughout many parts of the USA. RCG can grow by its seeds or its rhizomes. Its seeds are capable of surviving long periods in soil. RCG can potentially be controlled by multi-year treatments in early spring and early fall with broad spectrum or grass specific herbicides. The goal of this study was to optimize methods to control RCG, in order to increase species …