The objectives of this project are to gain a better understanding of the biology of confirmed and suspected herbicide resistant weed species and to evaluate putative management approaches. Prior research has confirmed the widespread occurrence of weed populations that are resistant to glyphosate in the Mississippi Delta. Some of these populations are also resistant to other herbicides, thus complicating their management and increasing the cost of control. Greenhouse and growth chamber studies will be conducted to identify herbicide resistance in weed species, characterize the resistance, identify mechanisms, evaluate additives and alternative herbicide chemistry options, and understand...