GFB News Magazine

UGA weed science experts weigh effects of dicamba ruling

Posted on August 25, 2020 8:00 PM

By Jay Stone

Cotton and soybean growers can  no  longer  use dicamba weed control  products following the U.S. 9th Circuit Court of Appeals’ June 3 ruling vacating federal approval of dicamba.

UGA weed science experts Stanley Culpepper and Eric Prostko provided analysis of the court decision and offered alternative weed control suggestions.

“The dicamba decision impacts nearly every farmer in the state,” Culpepper said. “In Georgia, we have all worked so hard to steward every pesticide and we should collectively be proud. However, this is a wakeup call in several ways. First, we must work together even harder generating sound science to preempt this type of situation in the future. Second, for those few growers who have downplayed the importance of using all pesticides wisely, what a wakeup call.”

In  a blog  post soon after  the  ruling, Culpepper laid out weed control options farmers could use. Culpepper emphasized that farmers should use only labeled products and follow all label directions and restrictions. He said Tavium registration was not affected by the court ruling.

Since farmers can no longer  use dicamba after July 31, only  one of  Culpepper’s original recommendations is still applicable - Scenario Three: large pigweed with no dicamba available. Sequential Liberty applications will be the best approach,  per Culpepper, whose  blog can be read at www.gfb.ag/culpepperdicambablog .

Georgia obtained a new state label for Liberty shortening intervals between sequential applications, which will improve control, according to Culpepper. Learn more at www.gfb.ag/libertylabel .

Prostko estimated that 75% of the soybeans planted in Georgia are dicamba tolerant.

“Growers do not have a choice in many cases,” Prostko said. “Unlike dicamba-tolerant cotton, current dicamba-tolerant soybeans are not tolerant to Liberty (glufosinate) so this herbicide cannot be used on Xtend soybeans.”

Prostko’s recommendation: the next best POST option would be Roundup + Reflex.