Survey shows dicamba may reduce the effectiveness of junglerice controls

In recent years, jungle rice has become a significant problem in dicamba-resistant cotton and soybean crops. In Tennessee, for example, growers routinely find populations of the weed that escape applications of dicamba plus glyphosate and/or clethodim—two 'go to' herbicide controls.

A recent survey featured in the journal Weed Technology explores the prevalence of junglerice in cotton and soybean crops and whether dicamba interferes with the effectiveness of herbicides used to control the weed.

In a two-year study, researchers from the University of Tennessee found jungle rice was the most prevalent weed to escape treatment in the dicamba-resistant cotton and soybean fields. It was found 76 percent of the time in cotton and 64 percent of the time in soybean.

"Our study suggests dicamba is reducing the effectiveness of both glyphosate and clethodim," says Clay Perkins, a member of the University of Tennessee research team. "We found glyphosate plus dicamba mixtures reduced jungle rice control by 25 percentage points compared with glyphosate alone. Clethodim plus dicamba provided 6.5 percentage less control than with clethodim alone."