Challenges and opportunities in implementing allelopathy for natural weed management

Plants may favorably or adversely affect other plants through allelochemicals, which may be released directly or indirectly from live or dead plants (including microorganisms). Due to increase in the number of herbicide-resistant weeds and environmental concerns in the use of synthetic herbicides, there have been considerable efforts in designing alternative weed management strategies. The conventional synthetic herbicides are becoming less and less effective against the resistant weed biotypes. The objective of this article is to examine the role of allelopathic cover crops/crop residues, natural compounds, and allelopathic crop cultivars in natural weed management. Numerous examples of employing crop residues, cover crops and allelopathic crop cultivars in weed management are provided. Although we cannot eliminate the use of herbicides, their use can be reduced by exploiting allelopathy as an alternate weed management tool for crop production against weeds and other pests. (C) 2003 Elsevier Science Ltd. All rights reserved.