Foxtail is the most common grass weed that competes with corn in Illinois, Hager says. “In the past, soil residual herbicides have typically taken care of it,” he says. “However, farmers tend to use lower rates of application now than they once did, and lower rates shorten the duration of weed control.”

Foxtail is also widespread across Iowa “at fairly significant levels of infestation, and it’s been that way since the 1950s,” Owen says. “For now, there is no significant herbicide resistance issue related to foxtail, but the early-season competition from this weed can really reduce corn yields if postemergence applications are less than timely.”

Owen recommends using the full rate of a soil-applied herbicide that has residual activity for foxtail and then following up with either cultivation or a postemergence application. “It’s relatively simple to control foxtail with either Ignite [glufosinate] or glyphosate, but the timing is extremely critical to prevent a drop in corn yields,” Owen says. “So, for Iowa, we recommend an early preplant application with a chloroacetamide herbicide, such as Outlook, Dual Magnum or another product with similar residual activity for foxtail sometime during late March or early April.”

In Nebraska, green foxtail tends to be more prevalent than giant foxtail, Sandell notes. “While glyphosate continues to provide excellent control of green foxtail, a diversified approach that includes an effective soil-applied preemergence herbicide helps producers eliminate early-season competition from foxtail and maintain high yield potential,” he says.