On October 27, 2020 the Environmental Protection Agency (“EPA”) announced that it had approved three dicamba-based pesticides for over-the-top use on dicamba-tolerant soybeans and cotton for the next five years. This means that during the 2021 – 2025 growing seasons, farmers will be able to spray the approved pesticides directly onto soybean and cotton crops which have been genetically modified to resist dicamba. The specific formulations approved by EPA include Bayer’s XtendiMax with VaporGrip Technology (“XtendiMax”), BASF Corporation’s Engenia Herbicide (“Engenia”), and Syngenta’s Tavium Plus VaporGrip Technology (“Tavium”). FeXapan Herbicide Plus VaporGrip Technology (“FeXapan”), made by Corteva, was not included in the registration.


Dicamba is a pesticide that targets broad-leafed plants, and is used to combat weeds that have grown resistant to glyphosate, including palmer amaranth which is commonly known as pigweed. Historically, dicamba has been used as a pre-emergent, meaning that it was applied to the ground in later winter or early spring before crops were planted. This was done because older forms of dicamba were prone to volatility which caused the pesticide to evaporate into the air after it was sprayed and drift onto nearby fields. However, in 2015 Bayer released a line of soybean and cotton seeds which were engineered to be resistant to dicamba, and in 2017 EPA approved XtendiMax, a lower volatility form of dicamba that could be sprayed directly onto the dicamba-resistant soybean and cotton plants. That initial registration was for two years, as was the subsequent registration which also included Engenia, Tavium, and FeXapan.

Label Changes

The new registration approved by EPA is for five years instead of two. According to EPA, it has reviewed additional data that has allowed it to make this decision. The new registration also comes with changes to the label that are intended manage off-site movement of dicamba. Those changes include:

  • Requiring a pH-buffering agent that has been approved by EPA to be tank-mixed with dicamba products prior to all applications to help control volatility
  • A downwind buffer of 240 feet, and 310 feet in areas where species listed under the Endangered Species Act are located
  • National cutoff of dicamba spraying on soybeans after June 30, and on cotton after July 30
  • An overall simplification of the label and use directions so that it will be easier for growers to determine when and how to legally apply dicamba.

The new registration comes after a case from the United States Court of Appeals for the Ninth Circuit concluded in June, 2020 that the previous registration for XtendiMax, Engenia, and FeXapan was unlawful and vacated the registration. In that case, the court concluded that the registration violated the Federal Insecticide, Fungicide, and Rodenticide Act (“FIFRA”) which governs federal pesticide registration. Under FIFRA, a pesticide will only be registered for use if EPA determines that registering the pesticide will not cause “any unreasonable adverse effect on the environment.” 7 U.S.C. § 136a. The text of FIFRA defines “unreasonable adverse effect on the environment” to include “any unreasonable risk to man or the environment, taking into account the economic, social, and environmental costs and benefits of the use of any pesticide.” 7 U.S.C. § 136(bb). According to the court, EPA had failed to consider several risks posed by dicamba when it concluded that registering the pesticides would not cause unreasonable adverse effects to the environment. Among those risks were non-compliance with complex label requirements, economic costs, and social costs. Specifically, the court was concerned about what it described as a “near monopoly” by Bayer of dicamba-resistant technology, and how dicamba used had “torn apart the social fabric of many farming communities.” For more information on that case, click here.

EPA feels that the new registration has addressed the Ninth Circuit’s concerns by providing additional control measures and implementing national cutoff dates.

Going Forward

It is very likely that the new dicamba registration will be challenged in court. The Center for Food Safety, which has filed lawsuits against previous dicamba registrations, has stated that it expects to challenge the most recent registration. It is uncertain how such a lawsuit will play out, but farmers, agricultural retails, and other stakeholders who use or sell dicamba should be aware that such a challenge is likely to occur.

It is also uncertain how the national cutoff date will affect previous dicamba use practices. In the past, EPA has not set cutoff dates. Instead, states have set their own cutoff dates, sometimes by applying for special permits under FIFRA which allow states to set local restrictions on already registered pesticides, and sometimes through purely state measures. There is currently some question as to whether the national cutoff dates set by EPA will preempt state-specific cutoff dates. While some states may wish to restrict use of dicamba earlier than the dates set by EPA, other states where planting is done later in the season may wish to permit dicamba use beyond what EPA has allowed. EPA has stated that it is willing to work with states to issue FIFRA special local restrictions permits for states that wish to “expand the federal [over-the-top] uses of dicamba to better meet special local needs.”


To read more about dicamba use and surrounding lawsuits, click here.

To read about the FIFRA registration process, click here.

To read the text of FIFRA, click here.

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