Efficacy of Dicamba-Based Herbicide Programs in Dicamba Tolerant Cotton

The prevalance of herbicide-resistant biotypes over the last couple of decades is due to reliance on one single herbicide mode of action for weed management.  The major troublesome herbicide-resistant weed in row-crop production in the southern United States is Palmer amaranth.  New herbicide-tolerant technologies are being developed with multiple modes of action to control these resistant weeds.  Field experiments were conducted to determine the efficacy of dicamba-based herbicide programs in dicamba-tolerant cotton at the Edisto Research and Education Center in 2012 and 2013 near Blackville, SC.  In each study, the dicamba-based herbicide treatments provided excellent control of broadleaf weeds (Palmer amaranth and pitted morningglory) with percent control being greater than 90%.  The treatments with dicamba, glyphosate, and glufosinate provided excellent control which reduced competition and protected overall yields.  Treatments applied PRE and POST 1 included high yields because of low to no competition from weeds.