Allelopathy in weed management: A critical review

Allelopathy is defined as both beneficial and deleterious biochemical interaction between plant and weeds, and / or plants and microorganisms through the production of chemical compounds that escape into the environment and subsequently influence the growth and development of neighboring plants. Allelochemicals are present in all types of tissues and are released into the rhizosphere by a variety of mechanism, including decomposition of residues, volatilization and root exudation. Allelochemical its structure and mode of action are different and may offer a potential for future development of herbicide. This paper describes the variety of weeds and crop species that exihibit aallelopathic interface either with crop or weeds.   Key words: Allelopathy, allelochemicals, agriculture, crop, weed.