Sorghum allelopathy for weed management in wheat

Weeds cause substantial decline in agricultural production. To overcome weed infestation modern agricultural practices adopted heavy use of a large variety of herbicides. With rising human health and ecological concerns about the adverse effects of indiscriminate use of farm chemicals research on alternative weed management methods is underway worldwide. Exploitation of allelopathic potential of different crop/plant species for weed management under field conditions is one such approach. Sorghum has been reported to contain several allelochemicals in its aerial as well as underground parts. It offers a great promise as a tool for weed management. We conducted a series of field experiments to test allelopathic effects of this crop on weed control and yield of wheat. We found that 10% w/v water leachate of aerial parts of sorghum (also called sorgaab) applied at 30 and 60 days after sowing can reduce weed biomass by as much as 49% with concomitant increase of wheat yield over 20% compared to control. Furthermore, use of sorgaab in combination of herbicides can significantly reduce the amount of herbicide use (by 50%) and get comparable grain yield of wheat as obtained by using the recommended dose of the herbicides. We concluded that sorgaab used alone or in combination with herbicide has a great promise in increasing weed control and grain yield of wheat. Application of this method of weed management has enormous economic and environmental benefits in wheat cultivation.