By Dr. Mark Loux
Replanting a corn field due to weather-related stand problems usually involves killing the first planting, which otherwise really just turns into a weed. A recent article by Dr. Aaron Hager in the U. of Illinois newsletter, “The Bulletin – pest management and crop development information for Illinois”, summarizes this and other herbicide issues for corn replant situations
Bottom line – the only methods to ensure complete control of the first stand of glyphosate-resistant corn are tillage or application of Select Max. Use of Select Max must be followed by a wait of six days before replanting corn, to avoid risk of herbicide injury. Gramoxone and glufosinate (assuming it’s not LibertyLink corn) can have substantial activity on the first stand of corn, but usually do not completely control it. These herbicides are most effective when applied with atrazine or metribuzin, and also when corn is tall enough that the growing point is out of the ground.