Abstract

Biotechnology can be used to enhance the management weeds in several ways. Crops have been made resistant to herbicides by inserting transgenes that impart herbicide resistance into the plant genome. Glyphosate-, glufosinate-, and bromoxynil-resistant crops are commercialized in North America. This technology has been highly successful, transforming weed management in several major crops. Selection for mutations that impart herbicide resistance to crops has also been successfully used to generate herbicide-resistant crops. There are several living microbial products for the biocontrol of weeds. These agents have not been very successful, but work is being conducted to improve them with biotechnology methods. The use of crops that produce their own herbicides (allelopathy) has been even less successful. Biotechnological approaches are being used to generate crops that can poison weeds with less or without synthetic chemical inputs. Research on natural phytotoxins from plants (allelochemicals) has also provided lead compounds for herbicide discovery.