Allelopathic Effects of Cajanus cajan L. on the Seed Germination and Seedling Growth of 6 Shrub & Grass Species

The allelopathic effects of Cajanus cajan L.on the seed germination and seedling growth of 6 receptive plants,including Lolium perenne cv.Mada,Festuca arundinacea cv.Fine Lawn,Setaria sphacelata cv.Narok,Leucaena leucocephala cv.,Macroptilum atropurpureum DC.and Trifolium repens cv.Haifa.,were studied by adopting indoor Petri dish bioassay.The results showed that the seed and leaf aqueous extracts of C.cajan could inhibit the seed germination and seedling growth of all receptors,and the effect depended on the quantity of seeds and different concentrations.The increases of the quantity of seeds and concentration could enhance the allelopathy.The quantity of seeds and the high concentration extract could reduce the seed germination rate,the radicle and hypocotyl growth and the quantity of root hair.Radicle length was more sensitive to the extract than seed germination rate and hypocotyl length and might be the most sensitive index to judge allelopathy.In this study,the sensitivity of the seed and the leaf extract of C.cajan was different among 6 receptors,L.perenne,F.arundinacea,S.sphacelata and T.repens were more sensitive to C.cajan.,but L.leucocephala and M.atropurpureum were less.At the same time,the allelopathy of the seed of C.cajan L.was stronger than the leaf extract.