How widespread is the problem of glyphosate resistant weeds in Iowa?
These are not widely spread. But looking to the future, they can be and may likely be unless growers begin to change how they manage weeds in glyphosate resistant crops. The concept of the convenience and simplicity of using glyphosate weed control systems is admirable but from an evolutionary perspective, convenience and simplicity likely enhance the speed at which these weeds will change from being primarily sensitive to glyphosate, to being primarily resistant to glyphosate. Q: So what do you recommend corn and soybean growers do? A: Growers need to think about using alternative herbicides, particularly those herbicides that have activity on these weeds that are showing the resistance to glyphosate. And using the herbicides that have residual activity on these weeds, such as a soil-applied, preplant or preemergence herbicide. Farmers need to look at their different application timings. We at ISU make a broad, across-the-board recommendation for corn and soybeans that a residual herb
