Lambsquarters is one of the first summer annuals to emerge in the spring, with approximately 25% of the plants emerging prior to any spring tillage or burndown herbicide application. Peak emergence is typically mid- to late-season, but lambsquarters can emerge throughout the growing season.1
Lambsquarters is one of the most prevalent weeds found in the U.S. Soybean Belt.1
Can reduce soybean yields up to 25% with less than one lambsquarters plant per foot of row.2
Cotyledons and seedling leaves have a mealy gray cast but turn green with age. Leaves alternate and are triangular, 1 ¼ to 10 inches long.3
Lambsquarters plants typically average around 3.5 feet but under the right conditions can grow to 6.5 feet.3,4
One lambsquarters plant can produce up to 176,000 seeds, and one study found that 32% of seeds remained viable after 20 years.2
Because of its early emergence, lambsquarters can be one of the more difficult weeds to control in soybeans. It is critical to make sure weeds do not exceed the maximum height for postemergence weed control.2
to diversify herbicide programs and weed control strategies.
with a burndown herbicide or tillage.
using a residual product within 2 weeks before planting or prior to crop emergence.
before weeds grow taller than 4 inches.
If weeds escape, use tillage or physically remove them before plants produce seed.
1 Take Action. United States Soybean Board (Sep. 30, 2019). Common Lambsquarters Management in Soybeans. Retrieved from http://www.weedscience.missouri.edu
2 Michigan State University Department of Plant, Soil and Microbial Sciences (Sep. 30, 2019). Common Lambsquarters. Retrieved from http://www.canr.msu.edu
3 University of Missouri Division of Plant Sciences (Oct 2, 2019). Weed ID Guide, Common Lambsquarters. Retrieved from http://www.weedid.missouri.edu
4 Farms.com Newsletters (Oct. 3, 2019). Lambsquarters (Chenopodium album L.). Retrieved from http://www.farms.com