Abstract

Richard M.S. Mulwa* and Lydia M. Mwanza

The use of herbicides has revolutionized weed control in many crop production systems. However, with the increasing development of weed resistances to many popular selective herbicides, the need has arisen to rethink the application of chemical weed control. Approaches to maintain the efficiency of chemical weed control include the discovery of new herbicide target sites in plants and the discovery/ synthesis of new, more potent herbicidal molecules. However, these approaches are expensive to execute, take considerably long times to succeed and may lead to increased chemical loads in the environment. Since many existing broad-spectrum herbicides are still effective, an alternative strategy adopted to ensure the safe use of broad-spectrum herbicides in a wide range of crops is the application of biotechnological techniques to engineer crop selectivity to these herbicides. In this review we summarize efforts being made to develop crop herbicide selectivity using biotechnology.