HPIPM:Common lambsquarters

Taxonomy

Domain	Eukarya
Kingdom	Plantae
Phylum	Magnoliophyta
Class	Magnoliopsida
Superorder	Caryophyllanae
Order	Caryophyllales
Family	Amaranthaceae
Genus	Chenopodium

Scientific Name

Chenopodium album

Common Name

lambsquarters

Common lambsquarters (Chenopodium album)

Compiled by Steve Lackman, Montana State University, Yellowstone County Extension

and Marjolein Schat, Montana State University from the following sources:

http://www.plants.usda.gov/java/profile?symbol=CHAL7

http://glyphosateweedscrops.org/Info/GWC-11.pdf

http://www.colostate.edu/Dept/CoopExt/4DMG/Weed/lmbqrtrs.htm

http://www.msuweeds.com/michigans_worst_weeds/common_lambsquarters/

http://www.entomology.wisc.edu/mbcn/fruit605.html

http://www.hort.iastate.edu/gluten/?pdf/grnhsechr.pdf

Identification and Life Cycle

Common lambsquarters (Chenopodium album) is a member of the goosefoot family (Chenopodiaceae), which also includes spinach and beets. Common lambsquarters is a summer annual. As a seedling, common lambsquarters has two long, linear-shaped cotyledons, and the first ovate-shaped true leaves are opposite. True leaves eventually become more distinctly alternate and may be purplish on the underside with both surfaces covered with white granules or a mealy substance. Mature plants have broadly triangle-shaped leaves with irregular, shallow-toothed margins. The stems can be green or reddish, are grooved, and can be smooth or hairless. Mature plants generally reach a height of 2 to 6 feet. At flowering, very small, green or gray-green flowers are tightly clustered at the tips of stems and branches. These flowers turn into seeds with a thin, papery covering. Seeds are smooth and shiny seeds. The majority of seeds are black and a few are brown. Brown seeds germinate readily, while black seeds are more dormant.

Habitats

Except for extreme deserts, common lambsquarters is found throughout most of the United States. Common lambsquarters prefers well-drained soils with high levels of nitrates, but can grow in compacted soil as well.

Impacts

Due to its early emergence and rapid growth rate, common lambsquarters is a successful competitor with many crops. However, as with most weed species, the exact degree of common lambsquarters competition is determined by weed density, the relative time of crop and weed emergence, and, the environment. In addition to competing for nutrients, moisture, and light, green common lambsquarters stems can hamper crop harvest by clogging up combines. Furthermore, common lambsquarters is a host for several crop diseases, including alfalfa mosaic virus, cucumber mosaic virus, bean yellow mosaic virus, clover yellow vein virus, potato virus, soybean mosaic virus, tobacco etch virus, turnip mosaic virus, and watermelon mosaic virus.

Biology and Ecology

Common lambsquarters is a summer annual that can emerge throughout the summer. Emergence begins before 150 degree days (GDD, base temperature 50°F). Spring-emerging common lambsquarters plants generally flower and set seed in late summer and fall. Later emerging plants can reach the reproductive stage in as little as 6 weeks. Prolonged drought may trigger early maturation. Common lambsquarters is primarily self-pollinated, although wind can cause some cross-pollination. This plant only reproduces by seed, and once plants flower, they set seed over a relatively short period before they die. An average common lambsquarters plant can produce more than 70,000 seeds. The seeds also can survive well in the digestive tracts of cows, sheep, and horses, so manure is considered a possible source for introducing seed. Under certain conditions common lambsquarters seeds can remain viable in the soil for several decades. Most seeds require some time before they are ready to germinate. Light and strong day and night temperature fluctuations increase common lambsquarters seed germination.

Management Approaches

As an annual plant, management should be directed towards preventing flowering and seeding. However, due to the prolonged emergence period this may be difficult.

Biological Control

Although several arthropods will feed on common lambsquarters seeds on the soil surface, there are no specific arthropod biological control agents available for this weed. Corn gluten meal has been found to reduce survival and root growth of common lambsquarters. For more information on ongoing corn gluten meal research please see http://www.hort.iastate.edu/gluten/?pdf/grnhsechr.pdf.

Mechanical and Cultural Control

Cultural practices that help control common lambsquarters include anything that makes the crop more competitive and reduces the success of the weed. Such practices include selecting crops with quick emergence, altering planting dates relative to weed emergence, planting to narrow rows and using higher seeding rates for greater crop competition, placing fertilizer with the crop (not the weed), and implementing crop rotations that discourage summer annual weed success. Late seeding in particular can give some control because common lambsquarters tends to germinate early in the season and those seedlings are killed through soil preparation or with a burndown herbicide. Underseeding a legume cover or forage crop in the small grain, or after harvest, can compete effectively with common lambsquarters if the grain and cover crops are dense and vigorous. Mechanical weed control operations, such as rotary hoeing and row cultivating can effectively control seedling weeds.

Chemical Control

Consult herbicide labels for additional rate, application, and safety information. Additional herbicide information can be found at http://www.greenbook.net.

Due to constantly changing labels, laws and regulations, the sponsors of this web site assume no liability for the suggested use of any chemicals noted in the management section. Contact your local pest management personnel for current information on labeled pesticides that can be used for the intended plant disease, insect pest or weed.

References

For more images please visit IPM Bugwood. http://www.ipmimages.org/search/action.cfm?q=common%20lambsquarter&Start=1&results=29