Allelopathic Potential Of Garlic (Allium sativum L.) On Germination And Seedling Growth Of Redroot Pigweed (Amaranthus retroflexus L.) renders it as bioherbicide

In this study, we identified the potential allelopathic effect of extracts of leaves and bulbs as well root exudates of garlic on redroot pigweed ( Amaranthus retroflexus L.) seeds and seedlings. Garlic cloves were grown in greenhouse over a periode of 8 weeks in strile soil. Whole plants were pulled out of the soil and washed with distilled water, dried at 50 C°and then ground. Treatment solutions of 0.75%, 1.5%, 2.25%(W/V) of garlic extract were prepared from stock solution of garlic powder(7.5% W/V) in double distilled water(DDW). Seeds grown in DDW served as control. Result showed that with increasing extract concentration, germination percentage and growth of Amaranthus retroflexus reduced significantly and seedlings more sensitive to garlic bulb extract. Furthermore, results showed that garlic root exudates in soil significantly reduced growth parameters (shoot length, root length, fresh weight and dry weight) in A.retroflexus. Finding of this research showed that potential allelopathic effects of garlic and as such, could be exploited as a bioherbicide in agricultural field.