Vermont is the first US state to ban the weedkilling pesticide paraquat, backed by lawmakers who cited concerns about research showing the chemical substantially increases the risk of the incurable brain ailment known as Parkinson’s disease.

Phil Scott, the governor, signed the legislation on Tuesday. The new law takes effect on 1 November, though it contains a provision allowing state regulators to issue special permits for paraquat use on fruit-producing tree orchards, berries and other “small fruit” crops up until 31 December 2030.

The law also calls for annual data reporting on any use of paraquat in the state, and a state-funded study on recommendations for alternatives to the use of paraquat for farmers.

Some lawmakers expressed concern that a ban will hurt the competitiveness of Vermont farmers if the chemical is still allowed for use in other states, and said more research is needed to fully prove a link between paraquat and Parkinson’s.