California officials banned a widely used farm pesticide Wednesday, handing a major victory to environmentalists while depriving farmers of a chemical they’ve employed for decades to protect almond orchards, cotton fields and more.

The decision by Gov. Gavin Newsom’s administration to ban the pesticide, known as chlorpyrifos, is also a significant rebuke to President Donald Trump. The U.S. Environmental Protection Agency under Trump has been defending the chemical against court challenges after the Obama administration took steps to prohibit its use.

“We’re saying, ‘Enough is enough.’ We can’t wait for the federal government, which has been very slow and has kind of flip-flopped,” Jared Blumenfeld, secretary of the California Environmental Protection Agency, said in an interview.

Chlorpyrifos, developed by Dow Chemical in the 1960s as an alternative to DDT, has been banned for residential use nationwide since 2001. The product has been linked to neurological problems among farmworkers and their children.