Phytochemical screening and allelopathic effects of melia azedarch L. on seed germination and seedlind growth of penisitum americanum L

Melia azedarach.L is a medicinal plant .Aqueous extract of leaves, bark and seeds of Melia azedarach.L were assayed at 1, 5 and 10g/L concentration with different time period to check the presence of phytochemicals and their allelopathic effect on seed germination, fresh and dry weight and seedling growth of Pennesitium americanum. Result revealed that aqueous extracts of   plant at all concentration and time period had significantly inhibited seed germination of P.ammericanum L. when compared with control. The inhibitory effect increases with increasing concentration of extracts and time period. The extracts of all parts of M.azedarach in all concentration and time period show inhibition in all parameters. The order of inhibition when compared different parts of M.azedarch was seeds >bark > leaves. The test of phytochemical screening revealed that aqueous and acetone extract contain terpenoid, tannins, flavonoid and volatile oil. Hence it is concluded that aqueous extract of these plant contain water soluble allelochemicals which inhibit the seed germination and seedling growth of pennisetum americanum L. It is suggested that these chemicals may be used as herbicides.