Weed alert: here's a look at three tough weeds to watch for this year, and how to keep new weed problems under control

摘要

Few Illinois farmers would have listed giant ragweed or waterhemp as a top weed problem 10 years ago. Today, they are among the most destructive and difficult weeds to control. What's more, something called "hophornbeam copperleaf" is starting to show up on the radar. This southern Illinois weed is moving north and invading some fields from late May through harvest. "I've received more late-season calls about hophornbeam copperleaf than any other weed in the past year or two," says University of Illinois (U of I.) weed scientist Aaron Hager. Over time, weed species survive and adapt to the crop production system being used. The trend to earlier planting and less tillage contribute to increasing populations of certain weeds, while shifts in weed biology and herbicide resistance pose other challenges. We asked U. of I. weed experts to name the top three weed contenders to appear on the scene in the last decade, and strategies on how to keep these weeds under control.