March’s above-average temperatures in the Midwest will continue into spring and early summer, according to the NOAA Climate Prediction Center. Summer annual weeds, such as kochia, giant ragweed, common ragweed and common lambsquarters, will likely take advantage of these favorable weather conditions and emerge earlier than normal.
The Iowa State University Extension recommends that growers minimize the risk of early-season weed competition by using a pre-emergence residual herbicide to reduce the number of weeds and delay their emergence in relation to the crop. A timely post-emergence herbicide application before critical periods can help further protect crops from weed competition and yield loss.
When determining an herbicide program for these early-emerging problem weeds, ensure it includes multiple effective modes of action. According to the United Soybean Board, kochia and common ragweed have shown resistance to four different modes of action while giant ragweed and common lambsquarters have shown resistance to two different modes of action.
Sign up for the Know More, Grow More Digest to receive twice monthly agronomic e-mail updates pertinent to your area.
All photos are the property of Syngenta or are used with permission.
Syngenta hereby disclaims liability for third party websites.