The EPA Says Farmers Can Keep Using Weedkiller Blamed For Vast Crop Damage

Enlarge this image toggle caption Dan Charles/NPR Dan Charles/NPR

For months, farmers from Mississippi to Minnesota have been waiting for the Environmental Protection Agency to make up its mind about a controversial weedkiller called dicamba. Some farmers love the chemical; other farmers, along with some environmentalists, consider it a menace, because it's prone to drifting in the wind, damaging nearby crops and wild vegetation.

This week, on Halloween evening, the EPA finally announced its decision. Calling dicamba "a valuable pest control tool," it gave farmers a green light to keep spraying the chemical on new varieties of soybeans and cotton that have been genetically modified to tolerate dicamba. The approval is for two years; the EPA will consider the issue again in 2020.

A coalition of environmental groups that had filed a lawsuit against the EPA's original approval of dicamba blasted the decision to keep it on the market. Paul Achitoff from Earthjustice said in a statement that "EPA's disregard of both the law and the welfare of ... species at risk of extinction is unconscionable."

The decision is likely to boost sales of dicamba-tolerant seeds next year. Some farmers, in fact, say that they'll be forced to plant them. Otherwise, their crops could be damaged by dicamba fumes drifting in from neighboring fields.

Dicamba has been a huge success for Monsanto, the company that sells both dicamba-tolerant seeds and a version of the herbicide that's specially formulated for use on them. This past year, dicamba-tolerant seeds were planted on some 40 million acres, representing close to half of all soybeans and cotton in the United States. Bayer, the German company that now owns Monsanto, expects that total to grow to 60 million acres in 2019.

Farmers turned to dicamba because glyphosate, their previous favorite weedkiller, isn't working so well anymore. Important weeds like Palmer amaranth have become immune to it.

Yet controversy erupted as soon as farmers started using dicamba in this new way. Despite new formulations of dicamba that were supposed to eliminate this problem, the chemical didn't stay where it belonged. In 2017, there were thousands of reports of damage to non-dicamba tolerant soybeans, vegetables, and orchards. In 2018, the number of complaints decreased, but according to estimates compiled by university researchers, about a million acres of crops still showed ill effects from dicamba drift.

The EPA did impose some additional restrictions on dicamba spraying. Starting next year, only certified pesticide applicators will be allowed to spray the chemical, and spraying will have to end by 45 days after planting in the case of soybeans, and 60 days after planting cotton.

Independent weed scientists, however, were unimpressed by those changes. Bob Hartzler, a specialist on weeds at Iowa State University, wrote on his web site, "I don't think that these new restrictions will have a significant impact on the problems we've seen the past two years."

Some states, including Arkansas, Missouri and Minnesota, had already imposed tighter restrictions on dicamba spraying — tighter, in fact, than the EPA's new rules. Arkansas took the toughest line, banning the use of dicamba after April 15. A group of farmers in Arkansas has filed a formal petition with the state's regulators, asking the state to relax that restriction. "There are several balls still in the air," says Larry Steckel, the University of Tennessee's top weed scientist. "It'll be interesting to see what some of the states do."

Meanwhile, a federal court still has not ruled on the lawsuit that seeks to overturn the EPA's original approval of dicamba.

Two of the country's best-known independent sellers of soybean seed, Beck's Hybrids and Stine Seed, urged the EPA last summer to set much tighter restrictions on dicamba use. They argued that dicamba drift was preventing farmers from being able to choose freely between different types of seeds. Many farmers, they said, were afraid to buy anything but dicamba-tolerant seed because of worries that other crops could be damaged by dicamba fumes.

David Thompson, the national marketing and sales director for Stine Seed, told The Salt that about half of the farmers who buy Stine's dicamba-tolerant seed are doing it partly because of worries that their crops could be exposed to dicamba drift.