At the end of any growing season, there are several weeds that escape control. Common lambsquarter, giant ragweed, common ragweed, horseweed (marestail) and velvet leaf are the most commonly mentioned. Herbicide resistant weed concerns are heightened by the widespread use of glyphosate. Suspected herbicide weed resistant samples can be tested, free of charge to soybean producers, at the MSU Plant Diagnostic Center.

To confirm field diagnosis of suspected herbicide weed resistance in a soybean field, a mature seed head of the suspected resistant plant must be submitted to the MSU Plant Diagnostic Center for a greenhouse grow-out analysis. The screening results are based on each submitted...