Screening and Future Exploitation of Allelopathic Plants as Alternative Herbicides with Special Reference to Hairy Vetch

Summary Allelopathic cover crops are one of the most promising application of allelopathy for weed control and reduce the synthetic herbicides input. Fifty three cover crop plant species (26 leguminous, 19 graminaceous and 8 others) were assessed for the allelopathic activity using Plant Box Method. It was found that leguminous cover crops such as hairy vetch (Vicia villosa) and velvetbean (Mucuna pruriens), graminaceous cover crops, such as oat (Avena sativa) and rye (Secale cereale), certain cultivars of wheat (Triticum aestivum) and barley (Hordeum vulgare) were promising. By bioassay screening, 23 species were selected for field tests. Fall-sown cover crops such as hairy vetch, rye, wheat, oat, grass pea, and mustard are more effective when compared to spring-sown cover crops. Hairy vetch was most promising for the weed control in abandoned fields because of its ability to die off during summer season to make a thick straw-like mulch.