​​​Slowing the Spread of Glyphosate-Resistant Johnsongrass

March 2013 | 13 min., 58 sec.
by Daniel O. Stephenson
Louisiana State University

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Glyphosate-resistant (GR) johnsongrass was confirmed in Louisiana in 2010. It is essential to develop a management plan for GR johnsongrass that includes crop and herbicide rotation. In corn, plant a hybrid that is Roundup Ready and Liberty Link, don’t apply an organophosphate insecticide in-furrow at planting, and utilize ALS-inhibiting herbicides such as Accent Q, Capreno, Corvus, and Steadfast Q. For GR johnsongrass management in cotton and soybean, utilization of varieties that are resistant to Liberty (Liberty Link) and applications of graminicides are crucial. If Roundup Ready cotton or soybean is planted, graminicides are the only herbicide choice if an area is infested with GR johnsongrass. However, reliance upon a single herbicide or herbicidal mode of action may lead to resistance; therefore, overuse of graminicides could cause resistance. Crop and herbicide rotations have the potential to effectively mitigate and/or manage GR johnsongrass.​

About the Presenter

Daniel O. StephensonDaniel O. Stephenson is a professor and Extension specialist in weed science and a research coordinator at the Dean Lee Research Station, Louisiana State University AgCenter, in Alexandria. He previously held positions at the University of Arkansas, the University of Florida, and Auburn University. Stephenson earned a BS in agronomy and soils and an MS in agronomy and soils–weed science from Auburn University and a PhD in crop, soil, and environmental sciences–weed science from the University of Arkansas.​

Contact Information:
Email: dstephenson@agcenter.lsu.edu


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