Weed to Watch: Common Lambsquarters
In the United States, common lambsquarters is a weed that is making some serious noise. While it has long been known to be resistant to triazines and ALS-inhibitors, it is the current buzz about glyphosate resistance that has growers and researchers worried. Researchers have been looking at the response of lambsquarters to glyphosate for quite some time, but as of yet, have not confirmed resistance. To date, greenhouse and field studies have shown inconsistent results. Even so, experts are keeping it on their radar.
One reason lambsquarters is a big threat is because of its germination period. A recent article in The Journal of New Ulm, Minn said that lambsquarters can germinate over a wide range of conditions and can even germinate after being buried for decades. Tillage promotes germination and peak emergence for lambsquarters frequently occurs within 2 to 3 weeks after the tilling of the soil, when soil moisture and temperatures are adequate. Generally, lambsquarters can begin to germinate many weeks prior to planting and continue into the season. Because growers often try to delay applications of glyphosate, particularly on soybeans, in order to control as many weeds as possible, the height of lambsquarters plants is often beyond label recommendations when glyphosate is eventually applied. Therefore, lack of control is difficult to attribute to tolerance to glyphosate herbicides.
Syngenta 2008 research on lambsquarters management in corn and soybeans showed that tank-mixing herbicides with different modes of action with glyphosate or using pre-mixes, like HalexTM GT provided equally good lambsquarters control and helps manage against the development of glyphosate-resistant weeds.
Have lambsquarters been an issue in your fields? To what extent? What management plan do you in place to control lambsquarters?
Read more about lambsquarters and Syngenta solutions to help control this weed. Also, check out The Glyphosate, Weeds, and Crop Series on lambsquarters to learn more about lambsquarters' biology and management strategies.
HalexTM GT is a trademark of a Syngenta Group Company.