Bayer faces a new setback following a ruling by a US appeals court to block sales of its dicamba weedkiller in the USA, Reuters reported on 4 June.

The move is another challenge to the German chemicals giant, which is also facing a legal battle over allegations that its glyphosate-based weedkiller Roundup causes cancer.

In its decision on 3 June, the 9th US Circuit Court of Appeals ruled that the US Environmental Protection Agency (EPA) had substantially understated the risks related to the use of dicamba, a chemical found in herbicides sold by Bayer and rivals that are sprayed on genetically engineered soyabeans and cotton.

The ruling also blocked sales of dicamba-based herbicides like BASF’s Engenia and Corteva Agrisciences’ FeXapan.

Bayer and BASF said they disagreed with the court’s judgement while Corteva said it was reviewing the decision and believed dicamba was safe to use, Reuters reported.

The ruling related to the EPA’s 2018 registration decision that had expired in December 2019, Bayer said, and the company would be seeking a new registration for the herbicide for 2021 and beyond.

“Depending upon actions by the EPA and whether the ruling is successfully challenged, we will work quickly to minimise any impact on our customers this season,” Bayer said.

The EPA said on 8 June that farmers had until 31 July to use their supplies of dicamba-based herbicides that they had on hand as of 3 June, Reuters reported.

“Our order will mitigate some of the devastating economic consequences of the court’s decision for growers,” the EPA said in a statement.

According to Bayer, about 60% of the US soybean crop this year is expected to be seeded with its dicamba-resistant Xtend soybeans, which need to be sprayed with the herbicide to ward off weeds that have developed a tolerance for glyphosate.

Bayer has reached verbal agreements to resolve up to 85,000 of the 125,000 Roundup glyphosate weedkiller lawsuits it faces in the USA, the Independent reported on 26 May.

Bayer had inherited the lawsuits when it bought US agrochemicals company Monsanto in 2018.

The verbal agreements were part of a US$10bn plan to end the Roundup legal battle. According to sources quoted by the Independent, Bayer was likely to announce the settlements, which needed approval from the supervisory board, this month.