Glyphosate-resistant Palmer amaranth and waterhemp have spread across Kentucky, indicating that they continue to be a growing threat to grain crop production in the state.

Palmer amaranth, waterhemp and marestail are the three most problematic weed species confronting corn and soybean growers, says Purdue University weed scientist Bryan Young. With the challenge of herbicide resistance, Young shares how overlapping residual herbicides can help effectively keep these problem weeds under control.