The Environmental Protection Agency is reviewing further restrictions on over-the-top applications of dicamba, announcing Tuesday that curbs imposed this year had failed to reduce complaints of herbicide drift.

But the agency didn’t set any new restrictions for the 2022 growing season and said that training programs using the 2021 restrictions could continue.

The agency said it would work with states that want to “further restrict or narrow the over-the-top uses" of the herbicide. 

The agency "is reviewing whether over-the-top dicamba can be used in a manner that does not pose unreasonable risks to non-target crops and other plants, or to listed species and their designated critical habitats,” EPA said in an update on dicamba. Despite this year’s control measures, incident reports for 2021 “show little change in number, severity, or geographic extent of dicamba-related incidents," EPA said.

The agency said it received nearly 3,500 reports in 2021 alleging effects from dicamba drift onto various non-target crops and that the actual number was likely higher.

"The number of reported incidents vary depending on the state. EPA received few incident reports from states such as Georgia, Louisiana, and Mississippi, where OTT (over the top) dicamba is widely used. In other states, such as Arkansas, Illinois, and Minnesota, reported incidents are numerous and widespread,” the agency said in a 73-page report.

The American Farm Bureau Federation, American Soybean Association and National Cotton Council issued a joint statement questioning the accuracy of the EPA report.

The groups said it “is not clear whether complaints were submitted to multiple sources/regulators and were therefore double-counted” and whether “EPA, state regulators, or others investigated complaints to verify injury or assess potential causes.”

Alan Meadows, a Tennessee soybean grower and director of ASA, said the EPA the report “provides an incomplete picture. Data that is not present in this EPA release may tell as much or more about the story than what the agency has included.”.

Kent Fountain, a Georgia cotton producer and chairman of NCC, said the report "doesn't align with what the U.S. cotton industry has seen and heard in the field. The data needs to be analyzed carefully to ensure accuracy because dicamba is too important to our industry for decisions to be made on incomplete or faulty data.”

About three-quarters of U.S. cotton acreage and two-thirds of the soybean acreage are planted with varieties that are dicamba tolerant

In a Dec. 9 letter to EPA Administrator Michael Regan, a bipartisan group of 13 House members, including Ag Committee Chairman David Scott, D-Ga, expressed concern about a decision to change label restrictions so close to the 2022 growing season. “Farmers would not be able to readily acquire enough seeds to accommodate a transition” from existing herbicides to alternatives, the lawmakers said.

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In a letter to President Joe Biden last month, commodity and farm groups including CropLife America, the Agricultural Retailers Association and American Seed Trade Association all asked EPA to “avoid label changes that would cause significant seed and pesticide demand shifts that supply chains will be unable to accommodate in the short time remaining ahead of the 2022 growing season.”

Bayer, which markets dicamba under the XtendiMax brand, said in a statement that it was reviewing the EPA report:

"We appreciate all the efforts made by growers this year to complete the pre-season training and implement the new EPA label requirements, which we believe helped the vast majority of XtendiMax herbicide users succeed with weed control and on-target applications this season. XtendiMax herbicide is a vitally important tool for growers, and we look forward to helping growers have a successful 2022 with the technology."

But Lori Ann Burd, environmental health director at the Center for Biological Diversity, said EPA’s latest findings justify banning the herbicide. "The ongoing devastation to non-target crops and natural areas caused by dicamba drift will never be averted through voluntary actions by the same pesticide companies that profit from selling it. Only a complete ban on this dangerous pesticide will end the harm.”

EPA said it estimated in 2020 that one incident was reported to EPA for every 25 incidents reported to USDA. EPA based the comparison on USDA’s 2018 Soybean Agricultural Resource Management Surveys.

The report said state agents "suggest that some applicators struggle with implementing the label requirements despite extensive training" while others "blatantly ignore the restrictions." EPA said it "is not always capable of distinguishing incidents resulting from misuse (of non-OTT dicamba or illegal applications of OTT-formulations) from incidents occurring after lawful use of OTT products."

The agency outlined several near-term measures that have been suggested by state regulators and extension specialists, including setting an earlier cutoff dates for applications or implementing a temperature-based cutoff. 

Earlier cutoff dates would reduce the amount of dicamba volatization in the hotter summer days, but that restriction "may render OTT dicamba products unusable for postemergence weed control in areas of the country with later planting dates, especially with soybean, resulting in reliance on limited other postemergence herbicide options (i.e., glufosinate) or decreased control of problematic broadleaf weeds," the report said. 

A temperature-based restriction on spraying dicamba would be harder to enforce than a cutoff date, the agency said.

The existing cutoff dates are June 30 for soybeans and July 30 for cotton.  

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