The plant was found in a field during a corn harvest in Stephenson County. It is native to eastern Asia and was first detected in the United States in 1990 in New York.
It spreads rapidly through seeds, which can move through landscapes via waterways. The University of Illinois Extension says there have been reports of herbicide resistance in the plant’s native range. Researchers are concerned the species could develop similar resistance in the United States.
Illinois is the third state where Asian copperleaf has been identified. The plant has already been found in 10 counties in central and western Iowa.
Identifying the plant without its reproductive structures can be difficult, but Extension officials say it is easiest to identify between harvest and frost or tilling. They recommend scouting for the plant during the growing season.
The University of Illinois Extension recommends harvesting fields containing Asian copperleaf last to reduce the chance of spreading seeds to other fields through harvesting equipment. Seeds also can spread through livestock manure, so Extension officials advise caution when grazing livestock in fields that may contain Asian copperleaf.
If you think you may have found Asian copperleaf in corn or soybean fields, the University of Illinois Extension can help confirm identification.
Check out the U. of I. factsheet for more information.
Copy Edited by Eryn Lent
