Herbicide-Resistant Weed Management in Dry Land Wheat Production Systems in the Pacific Northwest
Continuous use of herbicides with the same mode of action in dry land winter wheat production systems has selected for biotypes of herbicide resistant Italian ryegrass. Resistant biotypes are difficult to control and can significantly reduce yield of harvested crops. Herbicide resistant crops can be used to control weeds that previously were difficult to control in winter wheat cropping systems. The research will determine the extensiveness of herbicide resistant Italian ryegrass biotypes in winter wheat production systems in Washington and Idaho and provide effective management strategies for control of the resistant biotype. Additionally, this research will determine how to best use herbicide resistant crops to effectively control weeds in winter wheat production systems without selecting for herbicide resistant weeds.