EPA is considering comments expressing a wide diversity of opinion on whether to approve labels for three dicamba herbicides for use in 2026, setting up a potential third round of litigation over the controversial crop protection chemical.
Two court orders in recent years – one in 2020, one in 2024 – vacated the agency’s registrations after extensive crop damage was blamed on dicamba. The decision in early 2024 resulted in the products not being available this growing season – the first time that had happened since 2017.
Comments submitted to EPA vary in substance, but grower groups and farmers were generally in favor of approval but expressed concern about the complex nature of the proposed labels. Environmental groups and some growers are staunchly opposed to allowing the Bayer, Syngenta and BASF products back in the fields, citing extensive off-target damage caused by spray drift and volatilization, especially at high temperatures.
This year’s record soybean crop also was cited by a few commenters.
“The current USDA forecast for the 2025 U.S. soybean crop projects an average yield of 53.6 bushels per acre, the highest ever on record,” said one commenter who did not provide their name. “This unprecedented yield is being achieved despite the reduced or absent use of dicamba in large areas, demonstrating that farmers can achieve excellent productivity without reliance on this volatile herbicide.”
The registrations would be for use with cotton and soybeans that have been genetically engineered to withstand applications of the herbicide. To address the potential for damage to crops and plants beyond the application area, the proposed labels would prohibit any applications when the temperature exceeds 95 degrees and require the use of volatility reduction agents (VRA) in an amount that would be determined by the temperature.
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Farmers also would have to check weather reports before and during applications and choose practices from a mitigation menu designed to reduce impacts on sensitive areas and species.
Growers want to see fewer requirements, while environmental groups say the restrictions won’t make much difference.
“An across-the-board temperature cutoff at 95 degrees will prove almost impossible for soybean growers to spray dicamba, especially in the southern tier of the United States,” the American Soybean Association (ASA) comments said.
ASA also took aim at the requirement that “during frequently occurring temperatures between 85 and 95 degrees, the proposal demands reducing the application area by 40% or banning tank mixes. In regions of Tennessee and South Carolina that face difficult pest pressures, the temperature is regularly above 85 degrees during the summer months. This puts growers in a difficult position by forcing them to ignore good pest management practices.”
Brad Smith, a farmer in south-central Michigan who grows between 400-650 acres of soybeans every year, asked for “a label that allows me to use dicamba on soybeans with only common-sense restrictions.”
Too many sprays without dicamba, grower says
Brian Peterson, who farms in north-central Kansas, told EPA that without dicamba this season, “soybean fields have been sprayed over and over again trying to maintain control of weeds. In my opinion, taking an effective product away from our use that was effective in single applications to force us to use other products in multiple applications is not any safer to our environment.”
Grower groups said they need the chemical to combat resistant weeds. The Mississippi Farm Bureau Federation said it “believes that [over-the-top] dicamba products can be used in a manner that limits off-target movement.” The bureau also said it thinks “the number of off-target complaints is overstated based on our experience in Mississippi.”
Even at low levels, dicamba can be damaging to plants. University of Illinois researchers recently unveiled a new tool that can detect plant damage as low as one ten-thousandth of the herbicide’s label rate, up to eight days after application.
EPA documented dicamba damage to more than 1 million acres of non-GE soybeans and other crops in the 2021 growing season. In its memorandum supporting the proposed labels, the agency said the incidents of damage reported to state agencies had fallen, but that could be due to several factors, “including increased adoption of [dicamba-tolerant] traits through grower preference, defensive planting, or community planting efforts or increased familiarity with label mitigations, like the addition of a VRA, through training.”
The agency cited other possible reasons: Fear of “jeopardizing crop insurance payouts, reporting fatigue, fear of damaging relationships with neighbors, or pressure from stakeholders wanting to preserve [over-the-top (OTT)] dicamba use.”
An agronomist in Nebraska who submitted comments anonymously said in that state, “enforcement of label restrictions is practically nonexistent. Nebraska’s Department of Agriculture is severely understaffed, lacking the resources to regulate dicamba misuse effectively. This year, numerous farmers were reported for dicamba-related drift incidents, yet not one faced fines or penalties due to inadequate oversight.”
Stanley Culpeper (University of Georgia photo)A University of Georgia weed scientist said the volatility issue doesn’t exist in his state.
“The theory that off-target movement of dicamba is driven from volatility is non-factual in Georgia; to date there have been zero volatility drift complaints made in Georgia since commercialization of in-crop formulations including a volatility reduction adjuvant,” commented Stanley Culpeper.
The Center for Food Safety, which has been a plaintiff in the successful lawsuits, said the mitigation options outlined by EPA won’t work and that the labels should not be approved.
“EPA has proposed an entirely new, complex, unworkable and unenforceable mitigation scheme based on temperature[s],” the group said. “Applicators are required to consult the National Weather Service prior to spraying, and comply with one of three different volatile drift mitigation schemes depending on the maximum temperature that is forecasted on the day of or day after the planned application.”
CFS noted that EPA is proposing to eliminate a previous restriction that spraying not occur from “dusk to dawn” – the hours when most temperature inversions occur.
Those are defined as “stable air masses where the cooler air is near the earth’s surface and warmer air is on top,” according to the National Weather Service. “Since warm air rises, air under the inversion cannot escape because it is cooler than farther aloft. Smoke and pollution get trapped.”
EPA reasons that farmers should be informed enough to avoid spraying during inversions, but CFS said they “are not meteorologists, and may understandably make misjudgments and spray into inversions.”
