Corn replanting can occur immediately after application but control of existing corn plants could be improved if at least 24 hours elapse between application and replanting. Glyphosate also controls sensitive weeds that might have emerged with the initial stand of corn.
Other options to control emerged corn include paraquat and glufosinate (only for hybrids sensitive to glufosinate).
However, "Previous research with these herbicides has demonstrated that complete control is not always achieved," notes Hager.
Performance is often enhanced when these products are applied in combination with atrazine or metribuzin. "Paraquat and glufosinate would also control a broad spectrum of emerged weeds," he said.
Hager said that glyphosate-resistant corn from a first planting can be controlled with Select Max prior to replanting. "The label says to apply six fluid ounces per acre for control of glyphosate-resistant field corn up to 12 inches tall," he said.
Applications should include NIS and AMS - do not use a COC or MSO - and care must be taken to avoid in-field overlaps in order to prevent excessive injury to the replanted corn.
Glyphosate can be tankmixed with the Select Max to control emerged broadleaf weed species. "DO NOT replant corn in fields treated with Select Max sooner than six days after application, or severe injury to the replanted corn can occur," warned Hager.
The product labels of Poast, Poast Plus, Fusion, Fusilade, Select, and Assure II specify an interval that must elapse between application and rotation to, or replanting with, grass crops such as corn.
These intervals range from 30 days (Poast, Poast Plus, Select) to 60 days (Fusion, Fusilade), to as many as 120 days (Assure II), making these products unlikely choices for this particular use. FG
—From University of Illinois College of Agricultural, Consumer and Environmental Sciences news release
PHOTO
Severe injury to replanted corn can occur if soil residues of any ACCase-inhibiting herbicides are taken up by the emerging corn plants. Photo courtesy of University of Illinois College of Agricultural, Consumer and Environmental Sciences.
