ABSTRACT
The evolution of herbicide-resistant (HR) weeds in maize and soybean has been a major production issue. Generally, maize and soybean production systems have more flexibility, tools, and alternative strategies than other crop production systems. Changes in weed populations occur from the agricultural manipulation necessary to produce maize and soybean. Maize and soybean generally have a greater genetic potential for yield than what is actually realized. The chapter reviews the current world situation in maize and soybean production and provide an update on the development of HR weeds in these agroecosystems. It discusses the HR weed management strategies. The chapter proposes alternative tactics and provides a realistic assessment of these tactics. The basis for using herbicide tank mixtures to manage HR weed populations focuses on the need to include herbicides with different mechanisms of action that similarly control the target weed and have similar persistence in the agroecosystem.
