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Full-Text Articles in Agronomy and Crop Sciences
Distribution And Control Of Glyphosate-Resistant Johnsongrass (Sorghum Halepense) In Arkansas Soybean, Dennis Brent Johnson
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 …
Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Arkansas: Resistance Mechanisms And Management Strategies, Griff Michael Griffith
Glyphosate-Resistant Palmer Amaranth (Amaranthus Palmeri) In Arkansas: Resistance Mechanisms And Management Strategies, Griff Michael Griffith
Graduate Theses and Dissertations
Since 2000, there have been thirteen weed species confirmed resistant (R) to glyphosate in the United States, six of those resistant species are present in Arkansas. The goal of this research was to confirm and to determine the level of resistance in two R Palmer amaranth biotypes from Mississippi (MC-R) and Lincoln (LC-R) Counties, Arkansas, and one susceptible (S) biotype from Clarendon County, South Carolina, which had never been exposed to glyphosate. Shikimic acid concentration over time was significantly greater in the S biotype than both the MC-R and LC-R biotypes. The lethal dose required to kill 50% (LD50 …