On February 6, 2026, the Environmental Protection Agency (“EPA”) announced that it had re-registered three dicamba-based herbicides for direct, over-the-top use on dicamba-resistant soybeans and cotton. The decision came exactly two years after a federal court in Arizona overturned the previous registration decision for over-the-top use of dicamba and ruled that the decision violated the Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”). EPA’s latest registration decision marks the fourth time that the agency has approved dicamba for over-the-top use since 2016. All three of the previous registration decisions have faced legal action, a trend that will hold true for the latest registration which is already facing a lawsuit. Currently, over-the-top dicamba products will be available during the 2026 and 2027 growing seasons.

Background

The herbicide dicamba has been used in the United States since the 1960s to target broadleaf plant species. More recently, it has been used to control palmer amaranth, also known as pigweed, which has become resistant to glyphosate. Before 2016, dicamba was used as a pre-emergent. It was primarily applied in late winter or early spring before crops had been planted. This limitation was largely due to dicamba’s tendency to volatize, a process by which a pesticide evaporates into the air and can drift far off target. However, in 2016, EPA for the first time approved a new, low volatility dicamba product developed by the pesticide manufacturer Monsanto (now owned by Bayer) for use directly on soybean and cotton seeds that had been genetically modified to resist dicamba.

Ultimately, EPA’s decision to register dicamba for over-the-top use in 2016 lead to the registration of additional low volatility dicamba products such as BASF’s Engenia and Syngenta’s Tavium. It also resulted in a series of lawsuits filed by environmental groups who claimed that EPA’s 2016, 2018, and 2020 decisions to approve low volatility dicamba herbicides for use directly on crops violated both FIFRA and the Endangered Species Act (“ESA”). Under FIFRA, a pesticide product can only be sold and distributed in the United States after being approved by EPA. EPA may only approve a pesticide product for use after concluding that the product will not cause “unreasonable adverse effects on the environment.” 7 U.S.C. § 136a(c)(5)(C). The ESA requires all federal agencies to ensure that their proposed actions will not jeopardize the existence of threatened and endangered species by engaging in consultation with the United States Fish and Wildlife Service. 16 U.S.C. § 1536(a). The plaintiffs who challenged EPA’s 2016, 2018, and 2020 dicamba registrations decisions claimed that EPA failed to meet both those standards.

In 2020, the Ninth Circuit Court of Appeals issued a ruling to overturn EPA’s 2018 registration decision after concluding that the agency had failed to show that registration of over-the-top dicamba would not cause “unreasonable adverse effects on the environment.” The ruling was issued in June of that year, creating uncertainty for farmers who had purchased dicamba-resistant seeds to use with dicamba herbicides during that growing season. EPA ultimately reapproved over-the-top dicamba products for use later that year. That decision faced another lawsuit again filed by plaintiffs who claimed that EPA had violated both FIFRA and the ESA. That lawsuit also resulted in a win for the plaintiffs when a federal court in Arizona overturned EPA’s decision after concluding that the agency had failed to comply with the procedural requirements of FIFRA. That decision was issued in February 2024.

Following the Arizona court’s ruling, over-the-top dicamba was not approved for use during the 2024 and 2025 growing seasons. During that time, Bayer, BASF and Syngenta all resubmitted applications to EPA to have their low volatility dicamba formulations once again registered for use on dicamba-resistant soybean and cotton crops. In August 2025, EPA proposed to register three dicamba products for over-the-top use. The proposal included various new use restrictions intended to further reduce volatility and limit pesticide exposure to wildlife species. EPA sought an unconditional registration for the products, meaning that they would be available for at least fifteen years. Following a period of public comment, EPA issued a final registration decision on February 6, 2026.

Final Registrations

The final registration decision covers three dicamba herbicides: Stryax, manufactured by Bayer, previously known as XtendiMax; Engenia, manufactured by BASF; and Tavium, manufactured by Syngenta. Each of the three products has been approved for use on both dicamba-resistant soybean and cotton crops. The registration decision includes a variety of use requirements which will be included on the labels for each of the three products. Some of those requirements have been carried over from past dicamba approval decisions while others have been introduced for the first time. Importantly, in a departure from the initially proposed registration rule, the final decision approves a conditional registration decision which will expire on February 6, 2028, which means that the approved products will be available only for the 2026 and 2027 growing seasons.

The newly approved labels for over-the-top dicamba include various use requirements that are intended to ensure that applying dicamba directly to crops will not cause “unreasonable risk to human health or the environment.” Many of the requirements are aimed at reducing spray drift and volatility. Carry over requirements that were included on previous over-the-top dicamba labels include:

  • Mandatory use of an approved drift reduction agent;
  • Maintaining a 240-ft spray drift buffer during application;
  • A prohibition on applications during a temperature inversion, within 48 hours of a forecasted rainfall, if the soil is saturated, or within on hour after sunrise or after two hours before sunset;
  • A requirement that applications take place only when wind speed is between 3-10 miles per hour;
  • A complete prohibition on aerial applications.

Along with these carry over requirements, the recently approved labels include new restrictions intended to further reduce drift and to satisfy new conservation requirements under EPA’s Herbicide Strategy. More information on that policy is available here. The new requirements include:

  • An annual limit of two applications of 0.5 lbs of dicamba per acre – this is a reduction from the previous annual limit of four applications;
  • Use of a volatility reduction agency at 40 oz. per acre for every application;
  • Achieving 3 runoff mitigation points from EPA’s certified conservation practices menu with the possibility of 6 points needed in designated pesticide use limitation areas – this requirement is in compliance with EPA’s Herbicide Strategy;
  • A prohibition on applications is the temperature is forecasted to be at or above 95°F.

A more complete look at the various application requirements that will appear on the labels for the three over-the-top dicamba products can be found here, in EPA’s initial announcement, and here in documents from the final rule.

In a departure from the proposed registration decision made available last fall, the final registration decision has been issued conditionally for a period of two years. Under FIFRA, EPA may grant a conditional registration when it concludes that there is enough evidence to suggest that registering the pesticide product temporarily will not cause unreasonable adverse reactions to human health or the environment, but that more data is needed before EPA can make the decision to register the pesticide unconditionally. To date, all registrations of over-the-top dicamba have been conditional. According to the 2026 registration decision, the dicamba products will be available for the 2026 and 2027 growing seasons. EPA will need to make another registration decision if over-the-top dicamba is to remain available in 2028 and beyond. More information on the difference between conditional and unconditional pesticide registrations is available here.

New Lawsuit

Shortly after the new over-the-top dicamba labels were approved, a coalition of environmental groups initiated a legal challenge against EPA for its decision. The plaintiffs are the same groups who successfully saw prior over-the-top dicamba approval decisions overturned by courts in 2020 and 2024. The lawsuit has been filed directly in the Ninth Circuit Court of Appeals. Typically, lawsuits challenging final agency decisions will be filed in federal district courts, but FIFRA grants citizens the right to challenge pesticide registration decisions directly with circuit courts.

At the moment, it is too early to say how the case will resolve or even what the specific arguments raised by the plaintiffs will be. The case was initiated by the plaintiffs filing a petition with the Ninth Circuit asking the court to review EPA’s registration decision for allegedly violating both FIFRA and the ESA. The plaintiffs will lay out the reasons why they believe the registration decision violates federal law when they submit their opening brief to the court. Currently, the plaintiffs’ opening brief is due on May 11 and EPA’s response brief defending their registration decision is due on June 10. These dates may be adjusted if either party requests additional time to file. The court will not rule until it has seen arguments from both sides.

Lawsuits challenging federal decisions often take some time to move through the court system. When these same plaintiffs challenged EPA’s original 2016 decision to approve a dicamba product for over-the-top use, the lawsuit failed to reach the trial stage before the two-year conditional approval expired. When the plaintiffs filed again to challenge EPA’s 2018 registration decision for over-the-top dicamba, they asked the court to grant an expedited trial so that the challenge could be heard before the 2018 decision expired. It is possible that the plaintiffs could make such a request here so that the case can be heard by a judge while the 2026 approval decision is still active. If the court hears the case before the recent approval decision expires, it is possible that the court could overturn EPA’s approval and over-the-top dicamba could once again be made unavailable as the result of a court decision. On the other hand, the court could uphold EPA’s approval decision which could provide insight into future availability. If the case is not expedited, it is possible that the 2026 approval decision expires before the court can hear the matter. Whatever the outcome of this lawsuit, it could have an impact on continued availability of over-the-top dicamba.

What Next?

Currently, three over-the-top dicamba products are available for use in 2026 and 2027. While this provides clarity for the next two growing seasons, additional EPA action will be necessary if over-the-top dicamba is to remain available after February 6, 2028. Although this decision has provided greater certainty after two years where over-the-top dicamba was unavailable, the recently filed lawsuit could call that certainty into question as it moves through the court system.

 

To view the plaintiffs’ petition in Nat’l Family Farm Coal. v. EPA, click here.

To view the text of FIFRA, click here.

For more resources on pesticides from the National Agricultural Law Center, click here.

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