Modeling the Evolution of Barnyardgrass (Echinochloa crus-galli) Resistance to Glyphosate In Cotton and Its Management Implications

The increasing risk of barnyardgrass resistance to glyphosate may pose great challenges to current weed management programs in cotton. In Arkansas, barnyardgrass resistance has been confirmed for the herbicides including propanil, quinclorac, facet and command in rice production system and the risk of barnyardgrass developing resistance to glyphosate may not be far from realization. As such, we are in a need to develop proactive measures to slow the resistance evolution. Simulation models will be useful in this regard and a barnyardgrass resistance simulation model has been developed for cotton. The presentation will focus on the value of different non-chemical practices in slowing the rate of evolution of resistance. Recommendations on suitable cultural practices will be identified based on the model outputs.