Delayed Preemergence Corn Herbicide Applications

May 21, 1999
Soil-applied herbicides continue to be widely utilized for weed management in Illinois cornfields. Of the planted acres scheduled to receive some application of a soil-applied herbicide, most were treated prior to planting or prior to corn emergence. It is likely, however, that some cornfields were planted before the herbicide was applied and the crop has already emerged. Can a soil-applied corn herbicide be applied after the crop has emerged? Many, but not all, soil-applied corn herbicides can be applied even after corn emergence. Not all of these herbicides will control emerged weeds, so additional management procedures may be needed. Atrazine, cyanazine, and premixes containing these herbicides can provide postemergence control of certain annual broadleaf (2 to 3 inches) and grass (1.5 inches or less) weed species. Table 1 contains information about postemergence applications of the more traditional soil-applied corn herbicides. Consult the respective product label for additional information.--Aaron Hager, Marshal McGlamery

Author: Aaron Hager Marshall McGlamery