Limitations of Existing Weed Control Practices Necessitate Development of Alternative Techniques Based on Biological Approaches

Weeds constitute major losses to crops which necessitates the use of control practices. In conventional management systems, weeds are typically controlled using manual, mechanical, and chemical methods. Manual weeding is considered as most efficient control but its use has reduced due to shortage of labor for crop production on large scale and growing cost of labor. Mechanical weeding is suitable only for a limited number of crops and sowing methods. Additionally, requirements for multiple operations and adverse environmental impacts have limited use of mechanical weeding. Reliance on herbicides has increased over time due to convenience in application and quick response. Continuous use of herbicides has disturbed weed ecology, biodiversity, environment, and human health. They have caused herbicide resistance in weeds, shift in weed flora, and yield reduction of sensitive crops. Herbicide drift, persistence in soil, contamination of waterbodies, and accumulation of residues in plants have exposed all life forms to their hazardous effects. They are held responsible for many health disorders in human beings. So many challenges have been posed by chemical herbicides that the cost of weed control and limitations of other control methods now necessitate development of alternative techniques for at least integration into existing weed management practices. These alternative techniques may be based on biological approaches, i.e., inoculative biological control, inundative biological control, and allelopathy. A detailed review of limitations of currently used control methods and the feasibility of development of alternative techniques especially opportunities offered by rhizobacteria for weed management are discussed in this chapter.