A rare new weed species discovered in Iowa has experts asking growers to scout their fields and report any findings to the Iowa Department of Agriculture and Land Stewardship (IDALS) and Iowa State University.
Asian copperleaf is native to China, Australia and Japan, so its presence in the United States is unusual. With three detections in Iowa since 2016, most recently in Grundy County this year, agronomists say it can be problematic as the weed could be a threat to row crops and may be resistant to commonly used herbicides.

Prior to its discovery in Iowa, the only documented infestation of Asian...