Inhibitory effect of ragweed (Ambrosia artemisiifolia L)-inflorescence extract on the germination of Amaranthus hypochondriacus L and growth of two soil algae.

In this study the ecological importance of common ragweed (Ambrosia artemisiifolia L.; Asteraceae) was investigated in in vitro bioassays as it is one of the most widespread annual weeds occurring on arable land in Hungary. Eight fractions were derived from ragweed inflorescence water extract by low vacuum column chromatography and their biological activity was investigated by Amaranthus hypochondriacus L. cv. Edit (Amaranthaceae) germination bioassay. As a result of the germination bioassay the chromatographic method was modified to harvest the most effective fractions in only one fraction, which was used in three concentration (10, 50, 100 mg x kg(-1)) for algal growth inhibition bioassay. Results showed significant growth inhibition in case of both applied algal species.