Since mid-July, Missouri farmers have resumed spraying dicamba after a temporary ban on the controversial weedkiller was lifted by the state Department of Agriculture. Now, some farmers are reporting that damage to sensitive crops is reappearing — a lag time that suggests the injury occurred soon after the ban ended.

Tom Burnham, a Blytheville, Ark., grower who farms thousands of acres in Arkansas and across the state line in Missouri, says that “every acre” of his Missouri soybeans is showing symptoms of damage incurred since that time. He blames the recent applications of the herbicide, which can be prone to vaporizing — or volatilizing — and drifting off-target.

“We’re just now seeing the fallout,” said Burnham on Tuesday, noting that signs of damage, such as cupped leaves, take a week or two to emerge. “This has raised its head again in the last three days.”

In comparison, Burnham says the bulk of his acreage in Arkansas — where a similar dicamba ban remains in place — has been spared the same recent damage, with some fields near the state border standing as an exception.