Cover Crops, Residual Herbicides, and Application Method Reduce Selection Pressure Potentially Delaying Dicamba Resistance in Palmer Amaranth

Glyphosate-resistant Palmer amaranth (Amaranthus palmeri) has been the major weed problem in cotton for the past two decades. This weed is extremely unique in its biology and has the ability to develop resistance to multiple herbicidal mechanisms of action in a short amount of time. Studies were conducted in 2018 and 2019 to quantify the reduction in selection pressure of Palmer amaranth for dicamba resistance using integrated weed management strategies such as cover crops and residual herbicides applied preemergence and layby in cotton.