Trade watched closely

A Calhoun County farmer has reported Iowa’s fourth sighting of Asian copperleaf, a rare new weed species causing some concern as experts say it can pose a threat to row crops and may be resistant to commonly used herbicides.

The farmer had been aware of its presence since 2017, when he noticed it form a heavy cover in a late-planted crop. He reported it in mid-December 2022 following publicity surrounding a Grundy County sighting earlier this fall.

“It appears that the species was present for several years before discovery due to the sheer carpet of Asian copperleaf in the fields,” said Meaghan...