With a federally-mandated June 30 cutoff for dicamba use (June 20 in Illinois), most no-tillers who double-crop soybeans after wheat or barley won’t be using this herbicide as an over-the-top application. 

However, Ohio State University weed scientist Mark Loux says that if the small grain is harvested in time for dicamba to be applied for burndown before June 30, that would work with Xtend soybeans. However, there could be two possible loopholes. 

“I suppose one could apply the dicamba after wheat harvest when it’s fallow, and ‘forget’ you applied dicamba and plant double-crop Xtend soybeans,” he says. “But legally, the dicamba would be considered a preplant application to the Xtend soybeans and would not be legal if applied after June 30.”

June 30 Deadline

Travis Legleiter says RR2XtendFlex and approved dicamba formulations fit double-cropping when wheat is harvested early enough to no-till soybeans before June 30.

“In this scenario, a farmer could use dicamba in the wheat burndown and then use glufosinate and glyphosate postemergence,” says the University of Kentucky weed scientist. “However, this scenario doesn’t always play out in Kentucky where a lot of double-crop soybean acres are planted in July.”

Depending on the region, Bryan Young says a no-tiller could use XtendFlex soybeans and spray…