Abstract

This study was conducted on barley grains Hordeum vulgare L. (Misurata 04) and Emex Spinosus as an accompanying weed to test the phenomenon of Allelopathy by treating the plants grains with extracts of Leaves Acacia nilotica and Moringa oleifera at concentrations (20, 25, 35, 40%). for each of them, and the results were as follows:- Highly significant decrease in the percentage of germination of Hordeum and Emex seeds when using Acacia and Moringa leaf extracts at all studied concentrations. and a highly significant decrease in the lengths of the radicales and plumules of Emex seedlings when treated with both extracts and in all studied concentrations. Also, a highly significant decrease in radicales lengths of barley seedlings treated with acacia leaf extract in all studied concentrations. As for the extract of Moringa leaves, it had no significant effect on the lengths of the plumules and r radicales of the barley seedlings, except for the concentration (30%), which showed a very significant increase in the lengths of the plumules compared to the control. The results also showed a highly significant increase in the percentage of dry content and a highly significant decrease in the percentage of water content in the seedlings of both plants treated with both extracts at all studied concentrations. From the obtained results, both extracts of acacia leaves and Moringa had an inhibitory effect on the germination and growth of barley and Emex seedlings, but the greatest effect was of moringa extract on Emex seeds, especially in the high concentration, which completely prevented the germination of Emex seeds.