There have been numerous reports of poor control of cover crop or volunteer wheat with glyphosate + dicamba or glyphosate + dicamba + Leadoff over the last ten days. This poor control has been somewhat spotty and not occurred in every field. Earlier those very same treatments were providing consistent control of wheat across the board. The question is why the wheat control is inconsistent now with these glyphosate-based programs. I do not have any data but I can speculate. I think this unusual spring may be at least part of the answer as the wheat is much more mature here in late March than is typical. Much of the wheat has the flag leaf out and is fixing to head out. At this growth stage it may be less sensitive to glyphosate. At these later wheat growth stages Gramoxone typically does a good job and that herbicide would be an answer now to clean these fields up.
29 Mar 2012