A high level of uncertainty surrounds the properties of Asian copperleaf weed. What we do know is USDA Risk Analysis has classified it as “high risk” in 57% of simulations, despite the plant not showing strong invasive or weediness characteristics.¹
However, this should be taken with a grain of salt since the official USDA information on Asian copperleaf is fairly old. The weed may have been a bit of a sleeper out of the gate, but it’s begun showing up with more frequency in recent years.
Don’t let the uncertainty surrounding Asian copperleaf weed throw you for a loop. We’ve put together some fast facts and scouting tips to keep you ahead of the curve.
What to know about Asian copperleaf
Much of the research surrounding Asian copperleaf has been based in the state of Iowa, but still provides a valuable glimpse
- Asian copperleaf was first scouted in 2016 in a corn field in Iowa.
- The Asian copperleaf plant is native to East Asia, first spreading within Asia and to Europe.
- As recently as spring 2024, the weed has been found in at least six Iowa counties (Calhoun, Humboldt, Franklin, Grundy, Boone and Black Hawk).
- In the U.S., the potential distribution could reach 75% due to climatic zones suitable for growth (Zones 4-13).²
- Each Asian copperleaf plant can produce up to 300 seeds.³
- Asian copperleaf weed can prosper in light, sandy, medium and heavy clay soils, either acidic, neutral or alkaline. This weed prefers light shading and requires ample moisture.
- Asian copperleaf is a part of the spurge family, though it doesn’t have the milky sap produced by many spurges.
- Asian copperleaf is among the rising number of weed threats to corn and soybean that have shown herbicide resistant properties, including resistance to glyphosate and PPO-inhibiting herbicides.
How to identify Asian copperleaf
Asian copperleaf is difficult to scout and identify because it resembles many other common weeds. Additionally, since Asian copperleaf weeds emerge late in the season and don’t need much sunlight to survive, they can hide well under the crop canopy.
- When scouting for Asian copperleaf, the clearest distinguishing characteristic from other copperleaf weeds are the circular or heart-shaped bracts located beneath the flowers. However, this makes it extremely difficult to differentiate between Asian copperleaf and other copperleaf plants prior to flowering.
- Plants are upright and 2' to 3' tall
- Narrow, 2" to 3" oval-shaped leaves taper to a point at each end and have serrated edges.
How to manage Asian copperleaf
Much is still unknown about how to effectively manage Asian copperleaf. However, since Asian copperleaf contains herbicide resistant qualities, layering residuals or applying herbicides with multiple modes of actions can help you cover your bases.
If you spot Asian copperleaf in your fields, it is recommended to report it to the Iowa Department of Agriculture and Land Stewardship at 515-725-1470, or email entomology@iowaagriculture.gov.
Experts are available to help you make your decisions. Reach out to your seed retailer, a nearby extension office agent, or a seed company professional like your regional BASF representative.
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Endnotes
- Anderson, Meaghan. “Keep an Eye Out For This Weed.” Integrated Crop Management, Iowa State University, 5 Oct. 2022, crops.extension.iastate.edu/cropnews/2022/10/keep-eye-out-weed. Accessed 8 Dec. 2024.
- “Weed Risk Assessment for Acalypha australis L. (Euphorbiaceae) – Asian copperleaf.” Animal and Plant Health Inspection Service, 18 Sept. 2012, www.aphis.usda.gov/media/document/46867/file. Accessed 8 Dec. 2024.
- Abdiyeva, Rena T., and Svetlana A. Litvinskaya. “New locations and distribution of the alien species Acalipha australis L. (Euforbiaceae) in Azerbaijan.” Institute of Botany Plant & Fungal Research, June 2021, plantfungalres.az/uploads/2021/Abdiyeva,%20Litvinskaya.pdf. Accessed 8 Dec. 2024.
