Role of Allelopathy in Weed control-A review

Allelopathy is the releasing of the allelopathic compound by a plant species that checks the growth and development of another plant species. Weeds compete with main crops for nutrient, moisture, light, space, and water and acts as host plant for harmful pest and diseases. Manual weed management practices are laborious and expensive. In spite there are herbicides that control weeds significantly thus increasing yield, but continuous application of herbicides may develop weed shift and herbicide resistance. Recently research attention has been focused to find out alternative strategies for chemical weed control in several crops. Reduction in herbicide use is one of the major goals of modern agriculture and there is much emphasis in search for alternative weed management strategies that cheap, safe, and sustainable. Allelopathy is considered asan effective, economical and environment-friendly weed management approach. The release of allelopathy compounds from bark, leaves, stems, seeds, and roots of living and decomposing plant materials can influence weed density and growth. Keeping this in view, the literature on allelopathic effect on crops on weeds are reviewed in this paper.