Gov. Janet Mills has vetoed a bill to ban aerial spraying of some herbicides in Maine forestland.

Maine is the nation’s most heavily wooded state.

Democratic Senate President Troy Jackson introduced the legislation.

Jackson said he was deeply disappointed by the veto and said aerial spraying is “devastating” bodies of water, plants and wildlife.

Mills, a Democrat, said she will be issuing an executive order to further limit spraying.

But she defended the practice, saying it can be a tool for keeping forests healthy.