Ninth Circuit Court Declines Review of Enlist Herbicide Ruling

The Ninth Circuit Court of Appeals has declined to reevaluate its July 2020 ruling upholding the EPA registration of Enlist Duo herbicide for over-the-top use on Enlist cotton, corn and soybeans.

In a 2-1 judgment on July 22, a panel of three Ninth Circuit judges ruled that the premix of 2,4-D choline and glyphosate did not violate federal law. Several environmental groups including the Natural Resources Defense Council and Center for Food Safety appealed the ruling and asked for a larger panel of judges to review the case. That appeal was declined on Nov. 18.


In its original suit filed in 2017, the groups challenged EPA’s registration decisions regarding Enlist Duo, including volatility potential, increased herbicide use and its impact on environmental habitats for monarch butterflies and other species. The majority ruling dismissed all but one of the plaintiffs’ arguments and remanded EPA to reevaluate the herbicide’s impact on monarch butterflies, leaving the registration intact.

Any additional appeals would have to be directed to the U.S. Supreme Court.