Evolution of Herbicide-Resistant Weeds

Abstract

Among the greatest challenges to food security and sustainable food and fiber production from this day onward is weed resistance to herbicides. Resistant weeds have been reported in almost all ecosystems managed with herbicides. The cost of managing resistance goes beyond crop losses, added labor cost, and cost of additional herbicides. Weed resistance also forces farmers to abandon minimum tillage or zero tillage practice (momentarily) until the resistant weed population size is minimized. Managing resistance at a holistic level requires intensive educational activities and even government intervention at some point. It has a high opportunity cost. The genus Lolium, Amaranthus, and Echinochloa comprise the most problematic species thus far. More are on the threshold. The introduction of new herbicide sites of action, and how we use them, has not staved the evolution of herbicide-resistant weeds. Introducing new herbicide-resistant crops with up to four resistance traits will help manage resistant weeds in the short run. Without help from other tools and strategies, these too, will be overcome by weed adaptation eventually. New supplemental tools are in the horizon. Applications of remote sensing, robotics, nanotechnology, next generation sequencing technologies, bioinformatics, and biotechnology in weed management and crop improvement are promising. Taking agriculture through the 21st century and beyond requires unprecendented scientific innovation and global collaboration, combining old knowledge with cutting edge technologies, to achieve sustainable agriculture.