On February 6, 2026 the U.S. Environmental Protection Agency (“EPA”) issued a two-year registration for the so-called “over the top” (“OTT”) application of the herbicide Dicamba[1] to soybean and cotton crops genetically modified to be resistant to it. Four advocacy organizations[2] immediately filed a Petition for Review in the U.S. Court of Appeals for the 9th Circuit.
Dicamba was first registered in 1967. Controversary regarding the product began in 2016 following the approval of its OTT use on crops genetically modified to be resistant to it[3]. The OTT use allows application to developing crops which themselves would be killed by the dicamba without the modification, in theory allowing greater control of late developing weeds. As a result of this new use the annual volume of dicamba nearly quadrupled to thirty million pounds by 2019.
Problems were associated with the dicamba OTT use from its outset. Volatilization caused dicamba to be deposited on neighboring fields planted with non-GMO crops, causing extensive crop damage. The U.S. Department of Agriculture estimated that fifteen millions acres of soybeans were damaged.
In National Farm Family Coalition v. U.S. EPA[4], the Court invalidated the dicamba registrations. It found that EPA had significantly understated the risk to the environment of unreasonable adverse effects. The Court also found that EPA had ignored other risks, including the likelihood that users would not follow the complicated label directions, that the product would have anticompetitive impacts in the soybean and cotton industries and that the controversial nature of the product would adversely impact the social fabric of farming communities. Although the registrations were revoked on June 8, 2020, EPA allowed product already in the channels of trade to be sold and used.
The EPA Inspector General subsequently reported[5] that EPA had deviated from its standard procedures in reviewing dicamba pesticide registration applications. The Report found that EPA did not conduct the standard internal peer review of scientific documents created to support the decision to register dicamba for the OTT use. Furthermore it found that senior EPA officials altered documents, removing discussion of stakeholder risks.
Following cancellations required by the 9th Circuit decision, in October 2020, EPA again issued dicamba OTT registrations with a five-year life, adding new label directions and limitations on use. In 2022 EPA approved additional state-specific limitations for five states.[6]
These registrations were again challenged in Center for Biological Diversity v. EPA[7]. In a February 6, 2024 decision a judge in the District of Arizona revoked the 2020 registrations, including the state-specific label revisions, finding that EPA had neglected to engage in required notice and comment opportunities.
In its ongoing effort to maintain OTT dicamba registrations, on February 6, 2026 EPA reissued the dicamba OTT registrations for an additional two-year period, stating that the new registrations reflect “the strongest protections in agency history”[8]. Additional requirements of the new registrations include cutting the application rate in half; requiring the use of additional volatility reduction agents in the tank mix; and mandating limitations on application during high heat conditions conducive to volatilization.
These conditions are in addition to the extensive conditions previously imposed. Those conditions include a 240-foot downwind spray drift buffer zone; prohibiting dicamba use where specific dicamba-sensitive crops are grown; limits on applications during specified wind speeds or when a temperature inversion[9] is occurring or anticipated; limits on spray droplet size and nozzle height; and a prohibition on aerial application. Other user requirements also apply, including that the applicator be certified and undergo annual training wear specified personal protective equipment.
A Petition for Review was filed February 20, 2026 in the 9th Circuit.[10] Under the Petition Review process a simple notice is filed; the substance of the case is not presented until briefs are filed, a schedule for which has not yet been established.[11]
It remains to be seen whether what is now the fourth dicamba related action will succeed as the prior three have. A focal point of the arguments likely will be whether EPA had properly characterized the drift hazards and whether the new use limitations will be deemed to have adequately reduced that hazard. To the extent that the 9th was previously concerned about users’ ability and willingness to understand and comply with the complex use directions it would appear that the new labels are even more complex and challenging. The cotton and soybean market impacts are not likely to be a major point of contention. What is likely the case is that by the time the 9th Circuit issues a decision the 2026 use season will be underway and even if the 2026 registrations are revoked use will continue this growing season.
[1] Dicamba is the common name for 3,6-dichloro-2-methoxybenzoic acid.
[2] National Family Farm Coalition; Center for Food Safety; Center for Biological Diversity; and Pesticide Action Network North America.
[3] The registrants of OTT dicamba are Bayer [formerly Monsanto], Corteva (formerly DuPont) and BASF.
[4] 960 F. 3d 1120 [9th Cir. 6/3/2020].
[5] EPA Deviated from Typical Procedures in Its 2018 Dicamba Pesticide Registration Decision [Report 21-E-0146; 5/24/2121].
[6] Illinois, Indiana, Iowa, Minnesota and Sout Dakota.
[7] 2024 WL 455047; 2024 US DIST LEXIS 20307
[8] The EPA press release erroneously states that the dicamba OTT products have been “in continuous use” . That continuity was maintained only because the 9th Circuit allowed product already in the channels of trade as of the revocation of the registrations to continue to be sold and used.
[9] A temperature inversion is a meteorological condition wherein contrary to standard conditions a cooler air mass is capped by warmer air. The result can be among other effects the trapping and circulation of sprayed pesticides.
[10] 9th Circuit Case No. 26-2021
[11] OTT dicamba registrant BASF has already filed a motion to become an intervenor-defendant.