Autotoxicity of Ragweed Parthenium (Parthenium hysterophorus)

Ragweed Parthenium (Parthenium hysterophorusL. # PTNHY) was found to exhibit autotoxicity. The active principle(s) were isolated from two parts of the plant using polar system. Principle(s) from the inflorescence were more effective than from the leaves. Leachates derived from the plant decreased percent cell survival and chlorophyll content. Leachates from leaves were more toxic to ragweed parthenium when applied to the foliage than when applied through the roots. The polar allelochemicals were highly effective in preventing rooting and sprouting of stem cutting and in reducing the regeneration potential of mature ragweed parthenium plants.