Optimizing Post Respray Applications After Herbicide Failure

Postemergence herbicides in soybean can sometimes fail for a variety of reasons from applicator error to inclement weather. However, there is still a need to control weeds that have survived a failed POST herbicide application. This presentation will discuss how to optimize POST herbicide applications in soybean, how and when to scout for signs of herbicide failure, and what are the best timings and herbicide treatments for control of those surviving weeds. This will include product and timing recommendations for many possible herbicide failure situations taking into account efficacy and stewardship considerations. The information will be drawn from a combination of Purdue Weed Science field and greenhouse trials and the experiences and observations of several industry and academic weed scientists.