Role of Allelopathy in Weed Management: A Review

Allelopathy is the releasing of allelopathic compounds by one plant species that inhibit the growth and development of neighbouring plants of another species. Weeds, besides removing moisture and nutrients, harbour insects and diseases. Manual weed management practices are laborious and expensive. In spite of herbicides being effective in increasing yield, indiscriminate use of herbicides has resulted in serious ecological implications such as development of herbicide resistance weeds and shift in weed population. 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 major goals of modern agriculture and there is much emphasis in search for alternative weed management strategies that are cheap, safe and sustainable. Allelopathy is considered as an effective, economical and environment friendly weed management approach. The release of allelopathic compounds from leaves, flowers, seeds, stems and roots of living and decomposing plant materials can influence weed density and growth. Keeping this in view, the literatures on allelopathic effect of crops and trees on weeds are reviewed in this paper.