Effect of gamma irradiation on allelopathic potential ofSorghum bicolor against weeds and nitrification.

The effect of low doses of gamma irradiation on the allelopathic potential ofSorghum bicolor against weeds and nitrification was investigated. The results revealed that all test doses (500, 1000 and 1500 rad) significantly increased the allelopathic activity of root exudates, aqueous extracts, and decaying residues aganst seed germination and seedling growth ofAmaranthus retroflexus. The results also indicated that all test doses stimulated the allelopathic potential of aqueous extracts and decaying residues against nitrification activity. The possible application of this approach in biological control is briefly discussed.