Two new mechanisms for herbicide resistance found in Palmer amaranth

(University of Illinois College of Agricultural, Consumer and Environmental Sciences) Palmer amaranth is a nightmare of a weed, causing yield losses up to 80 percent in severely infested soybean fields. It scoffs at farmers' attempts at control, having evolved resistance to six classes of herbicides since its discovery in the United States 100 years ago. And now, scientists have discovered it has two new tricks up its sleeve.