The notoriously volatile weedkiller dicamba was blamed for 3,500 incidents of “off-target” damage this year, including to more than 1 million acres of soybeans, said the Environmental Protection Agency on Tuesday. The regulator said it was reviewing whether dicamba “can be used in a manner that does not pose unreasonable risks” and said it would help states that wish to restrict use of the herbicide.
However, the EPA said that it was unlikely to change federal regulations on dicamba usage before the 2022 planting season, four months away, due to the multistep rulemaking process it is obliged to follow.
“This cowardice is contrary to EPA’s core legal duties and will leave farmers and the planet unprotected for yet another year,” said the Center for Food Safety, a skeptic of industrial agriculture. The CFS said the EPA ought to revoke its approval of dicamba given questions about its safety.
As quickly as farmers embraced dicamba, introduced in 2017 as a new tool against herbicide-resistant weeds in cotton and soybean fields, neighbors began reporting telltale damage to their crops. Dicamba evaporated from where it was sprayed and drifted onto nearby crops, including rice, peanuts, and grapes, as well as onto trees. A week before the 2020 elections, the Trump administration approved the use of dicamba through 2025 with new safeguards to protect neighbors.
“Despite the control measures … the 2021 incident reports show little change in number, severity, or geographic extent of dicamba-related incidents,” said the EPA. More than 280 reports came from counties that have added restrictions on dicamba to protect endangered species. The EPA estimated that only one in 25 incidents was reported, pointing to, as an example, a USDA survey of soybean growers that found far more reports of damage than EPA had received.
All the same, three large U.S. farm groups questioned whether the EPA had double-counted complaints and whether anyone had investigated damage reports to verify the cause. “The stakes are simply too high to make major label changes without due diligence from EPA to learn all the facts surrounding reported incidents,” said Zippy Duvall, president of the American Farm Bureau Federation.
“Given the new information from the 2021 growing season, EPA is reviewing whether over-the-top dicamba can be used in a manner that does not pose unreasonable risk to non-target crops and other plants, or to listed species and their designated critical habitat,” said the agency in a statement. “EPA is also evaluating all of its options for addressing future dicamba-related incidents.
“EPA is committed to helping states address issues related to incidents in their jurisdictions,” it continued. “If a state wishes to further restrict or narrow the over-the-top uses of dicamba, the agency will work with them to support their goals.”
Resistance to dicamba among two species of invasive weeds, Palmer amaranth and waterhemp, has been reported in seven states and is likely to spread, said the agency.
Dicamba is used by farmers in conjunction with cotton and soybean seeds genetically engineered to tolerate the chemical. About three-fourths of cotton plantings and two-thirds of soybean plantings nationwide used dicamba-tolerant seeds, said the EPA, with dicamba sprayed on half of the cotton and soybean land after the seeds sprouted. Farmers sowed 87.2 million acres of soybeans and 11.2 million acres of cotton, or a combined 154,000 square miles, last year.
The EPA said it had “received nearly 3,500 reports alleging effects from off-target movement of dicamba onto various non-target vegetation, including cotton and soybean varieties that are not dicamba-tolerant, ornamental plants, other crops (sugarbeet, rice, sweet potato, peanut, grapes, cucurbits, vegetables, fruit trees, caneberries), and natural areas.” Damage was reported to more than 1 million acres of soybeans that were not bred to tolerate dicamba.
Some stakeholders have recommended much stricter rules on the use of dicamba or even outright withdrawal of EPA approval to use the weedkiller on some or all crops. If that happened, growers would probably switch to GE cotton and soybean varieties that are compatible with 2,4-D herbicides. “However, dicamba users and seed companies may not be able to quickly adjust to the loss of dicamba, given available supplies of alternative herbicides and tolerant seed, especially since growers make seed choices months in advance of the growing season,” said the EPA.
An EPA question-and-answer sheet on dicamba regulation is available here.
The 73-page EPA memorandum on 2021 dicamba use, incidents, and stakeholder-suggested mitigations is available here.
An EPA chronology of recent decisions on dicamba is available here.