ALLELOPATHIC EFFECTS OF JATROPHA CURCAS L. LEAF AQUEOUS EXTRACT ON EARLY SEEDLING GROWTH OF PARTHENIUM HYSTEROPHORUS L.

Jatropha curcas L. (J. curcas)is gaining interest as biodiesel plant in Pakistan. Therefore, it is necessary to investigate the interaction of J. curcas not only with crop plants but also with weed species before its introduction into agroforestry systems. During present investigation, allelopathic potential of J. curcas leaf aqueous extract was investigated on seed germination and seedling development of Parthenium hysterophorus L. Extracts were applied at 25%, 20%, 15%, 10% and 5% as seed soaking for 8 hours prior to sowing. Phenolics compounds were found in aqueous extracts and were higher in 25% extract (52.72 mg gallic acid eq. / gm of extract). Higher concentration of the extract (25%) significantly decreased seed germination (%), seed germination index, shoot fresh weight, shoot dry weight, root length, root fresh weight, root dry weight, seedling relative water content and seed vigor index. It was inferred from findings of the present investigation that aqueous extract of J. curcas exhibits inhibitory effects on growth and development of P. hysterophorus and therefore could be a potential source of botanical herbicide in the control of this noxious weed species. [ABSTRACT FROM AUTHOR]