Federal court bans use of dicamba weedkiller on crops; ruling says EPA broke the law when it reapproved it in 2020

Dicamba can cause stunted growth and yield
reduction in plants. (Farm Progress photo)

Dicamba, a weedkiller used to eradicate broadleaf, brush, vines and woody plants in agricultural crops, was banned by an Arizona federal court, which ruled that "The Environmental Protection Agency broke the law in allowing them to be on the market," reports Johnathan Hettinger of The Guardian. "The ruling is specific to three dicamba-based weedkillers manufactured by Bayer (Monsanto), BASF and Syngenta, which have been blamed for millions of acres of crop damage and harm to endangered species and natural areas across the Midwest and South."

The three companies dominate the agrochemical sector, and this ruling is the second to outlaw their dicamba-based herbicides, which are sold on shelves as Banvel, Trimec, Vanquish and Q4 Plus. "In 2020, the Ninth Circuit Court of Appeals issued its own ban, but months later, the Trump administration re-approved the weedkilling products," Hettinger explains. "In this ruling, an Arizona federal court found the EPA "made a crucial error in re-approving dicamba, finding the agency did not post it for public notice and comment as required by law."

Dicamba was introduced in the United States in the late 1960s, but remained unpopular because of how the chemical interacts with the environment. For instance, it "can volatilize and move long distances when temperatures climb," Hettingger reports. "It is also prone to drifting on the wind far from where it is applied. And it can move into drainage ditches and bodies of water as runoff during rain events."

To address the chemical's harmful elements, "Monsanto, along with the chemical giant BASF, introduced new formulations of dicamba herbicides they said would not be as volatile, and they encouraged farmers to buy Monsanto's newly created dicamba-tolerant crops," Hettering notes. "The EPA first approved Monsanto and BASF versions of dicamba for the 2017 growing season. Since then, dicamba has caused millions of acres of crop damage and has been the subject of several lawsuits."

Rhonda Brooks reports for Farm Journal: The "EPA has not said when it will respond to the court's decision. The ruling, for now, means U.S. farmers will not be able to use dicamba for weed control this season."