Allelopathy by Lantana camara L

Lantana camara l.,is a common wild shruby ornamental and hedge plant growing from plains to an elevation upto 1500m in pakistan. aqueous extracts of all parts of lantana camara have strong allelopathic effect on the germination and growth of various test species. however,the relative toxicity of various parts varied among themselves and against the various test species used. hot water extracts from leaves were more toxic than stems followed by fruit extracts. alcoholic extracts did not affect the germination of three test species. natural rain leachates of different plant parts invariably suppressed the germination and growth of various test species. lantana soil when tested showed no inhibitory effects on the germination and growth of test species. soil analysis indicated that caco3 and organic matter were low in control soil compared with lantana-affected soil. among major elements only p was higher in control soil than lantana-affected soil. the cell sizes of both plumule and radicle in all the test species reduced,especially in leaf extracts. the most affected species was allium cepa. paper chromatography suggested the presence of p-oh-benzoic acid,p-coumaric acid,caffeic acid,vanillic acid,ferulic acid,syringic acid and gentisic acid. these compounds have known inhibitory activity against many species.