The US Environmental Protection Agency (EPA) announced on 31 October that it will allow the use of Bayer AG’s controversial dicamba weed killer for another two years but with additional restrictions in place, Reuters reports.

“By extending the registration for another two years with important new label updates that place additional restrictions on the product, we are providing certainty to all stakeholders for the upcoming growing season,” said EPA acting administrator Andrew Wheeler.

Farmers had complained for several years that dicamba drifted away from where it was sprayed on soya and cotton crops engineered to resist it, to neighbouring plants – such as fruit trees and flowers – that could not tolerate it.

The EPA will prohibit the use of the dicamba on soybeans 45 days after planting, and 60 days on cotton, and has also limited the times when dicamba can be sprayed.

Farmers had been awaiting the EPA’s new restrictions to determine whether they would order dicamba-resistant seeds to plant next year, the Reuters report said.

Bayer bought Monsanto and its portfolio of dicamba-resistant soya seeds for US$63bn this year. With weeds developing a tolerance to glyphosate weed killer, making Monstanto’s Roundup Ready line of GM seeds lose effectiveness, Bayer is banking on its dicamba-resistant soyabean seeds to dominate US soya production.

Bayer, as well as BASF and DowDuPont Inc, all sell dicamba herbicide.