Dicamba on trial: Weed scientist: With widespread pollution, ‘no way’ to know where drift that harmed peaches came from

CAPE GIRARDEAU, Mo. - The air in parts of the Midwest and South has become so contaminated with the weed killer dicamba that it has caused widespread damage to soybeans and other crops in recent summers, testified Dr. Ford Baldwin, a professor emeritus of weed science at the University of Arkansas in federal court on Thursday. Amid the pollution, thousands of farmers have filed complaints about cupping leaves, stunted growth and lower yields. Among those is Bill Bader, the owner of the largest peach farmer in Missouri, who is suing German agribusiness giants Bayer and BASF, alleging they created the situation with the release of their joint dicamba cropping system. 

The lawsuit alleges that the companies released their dicamba-related products beginning in 2015 knowing that it would result in damage to farms, creating more demand for their products. 

The contamination is occurring because so many farmers are spraying so much of the weed killer at the same time that it builds up in the air to high enough levels that it is unable to dissipate, Baldwin said. Small amounts of the weed killer volatize, or turn into gas, and in stable atmospheric conditions, what is effectively an invisible cloud of weed killer spreads across the landscape, he said.