The U.S. Court of Appeals for the Ninth Circuit issued a decision Wednesday vacating the registrations of three dicamba herbicides, XtendiMax (Bayer), Engenia (BASF) and FeXapan (Corteva). The ruling does not appear to include Syngenta's Tavium dicamba herbicide.

The ruling has enormous implications for farmers this summer, given that roughly 60 million acres of dicamba-tolerant cotton and soybeans were slated for 2020 planting, with the expectation that farmers could use dicamba over the top for weed control.

At least one dicamba registrant, Bayer, has vowed to fight the ruling and try to mute its effect on farmers this growing season.

"We strongly disagree with the ruling and are assessing our options," a company statement emailed to DTN said. "If the ruling stands, we will work quickly to minimize any impact on our customers this season. Our top priority is making sure our customers have the support they need to have a successful season."

The Ninth Circuit's ruling came from a lawsuit brought against EPA and Monsanto (now Bayer) in 2017 by a coalition of farming and environmental groups, namely, the National Family Farm Coalition, the Center for Food Safety, the Center for Biological Diversity and the Pesticide Action Network. The lawsuit alleged that EPA violated both the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA), as well as the Endangered Species Act (ESA) when it first registered dicamba for use on dicamba-tolerant crops in 2017.

The lawsuit was mooted and refiled after the 2018 re-registration decision by EPA, but with largely the same claims. The court held a hearing on the new lawsuit's claims on April 21.

In its ruling, the Ninth Circuit ruled that EPA did violate FIFRA with the dicamba registrations, but the judges did not rule on the lawsuit's Endangered Species Act claims.

The Ninth Circuit justices strongly criticized EPA's decision to re-register three dicamba herbicides in 2018, after widespread reports of off-target injury in both the 2016 and 2017 growing seasons.

The ruling concluded that EPA "substantially understated" the amount of dicamba that would be sprayed, as well as the reality of injury reports across the Midwest and South.

"EPA refused to estimate the amount of dicamba damage, characterizing such damage as 'potential' and 'alleged,' when record evidence showed that dicamba had caused substantial and undisputed damage," the ruling stated.

The justices also stated that EPA failed to consider how difficult the new label restrictions crafted in 2018 would be to follow, as well as the technology's 'anticompetitive effect' on the cotton and soybean market and its divisive nature among the agricultural community.

"[T]he EPA entirely failed to acknowledge the risk that OTT dicamba use would tear the social fabric of farming communities," the justices wrote.

"We therefore vacate the EPA's October 31, 2018, registration decision and the three registrations premised on that decision," the ruling concluded.