Palmer Amaranth Population Dynamics in Cotton with Herbicide Programs Including Dicamba

Palmer amaranth continues to be a challenging weed control in southern cropping systems. Cultural practices and alternatives modes of action are tools used to improve management of this weed. The value of herbicide rotation in cotton with respect to dicamba has not been evaluated in long-term experiments. Research was conducted to compare programs including glyphosate, dicamba, and residual herbicides to control Palmer amaranth in four consecutive years of cotton. Dicamba was effective in decreasing the Palmer amaranth seed bank compared to programs with glyphosate only or preemergence herbicides followed by glyphosate only.