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.
Very interesting observation. A weed scientist’s work is never done!
Tom
Thanks for the comment. All growing seasons are interesting but this one has been exciting with the early start.
I had winter wheat that was only four inches tall that roundup did not kill. This wheat was sprayed in mid feb. when the daytime timperature was 61 degrees nad the nighttime temp. was 49. I also used 12oz. of dicamba. 2 oz. of valor 2.5 lbs. of ams per acre.
Richard
The inconsistent control on wheat this year is perplexing. However we are not in this alone as it is even been reported in Mississippi
Thanks
Larry