By Tom Polansek
CHICAGO (Reuters) -A U.S. court has nullified the government's latest approvals of certain agricultural weedkillers sold by Bayer (OTC:BAYRY), BASF and Syngenta, fueling uncertainty among farmers who spray the products on genetically engineered soybeans and cotton.
Environmental activists cheered the court for halting use of the dicamba-based herbicides, which are known to drift away and damage crops that cannot tolerate the chemical.
Some farm groups and agribusinesses said the ruling, if enforced by the federal government, risks hurting farmers financially and reducing options for fighting weeds that are increasingly developing resistance to a limited number of herbicides.
U.S. District Court Judge David Bury in Arizona this week vacated the Environmental Protection Agency's (EPA) registrations of dicamba-based weedkillers from 2020, saying the agency violated procedures mandating public input. The ruling affects Bayer's XtendiMax, BASF's Engenia and Sygnenta's Tavium, commonly used herbicides on U.S. farms.
Bayer soybeans that resist dicamba-based herbicide are the No. 2-most planted soybeans in the United States, though not all are sprayed with the chemical.
Most soybean and cotton farmers have already determined which seeds and chemicals they will use for their next crops that will be planted in the spring, BASF said.
Supply chains "will be significantly affected by the unanticipated chemistry demands on more than 40 million dicamba-tolerant soybean and cotton acres directly impacted by this order," BASF said.
The companies said they disagreed with the ruling and were awaiting guidance from the EPA.
"We haven't yet quite figured out what our response is to the decision itself," Michal Freedhoff, an assistant EPA administrator, said at the National Association of State Departments of Agriculture conference in Washington.
"We recognize there are some very near-term existing stocks questions we have to answer and we're definitely prioritizing those."
The ruling bars farmers from spraying dicamba products in the upcoming growing season unless the EPA allows them to use stocks of the herbicide that have already been shipped, said Meredith (NYSE:MDP) Stevenson, staff attorney for the Center for Food Safety.
"It's safe to say that, since most over-the-top dicamba products have likely not been shipped to growers, they will not be used this upcoming growing season," she said.
In June 2020, a U.S. appeals court blocked dicamba-based herbicide sales and ruled the EPA understated risks related to sprayings. The EPA, under former President Donald Trump, subsequently said farmers could use their existing supplies before it eventually reauthorized use again with new restrictions in October 2020.
Under President Joe Biden, the agency in December 2021 questioned whether dicamba weedkillers could be sprayed safely on soybeans and cotton without posing "unreasonable risks" to other crops.