The reduction of yield due to the allelopathic effect of weeds is a major concern in rice field. The present study was conducted to evaluate the allelopathic potential of the aqueous extracts of three weeds (Parthenium hysterophorus L., Scirpus articulatus L. and Eleocharis congesta L.) on germination and seedling growth of rice. Three concentrations viz., 0.5%, 1%, and 2% of each weed extracts were tested. The results showed that aqueous weed extracts of P. hysterophorus, S. articulatus and E. congesta significantly reduced the germination of rice compared to non-treated controls. Further, weed extracts significantly decreased the seedling growth and biomass of rice seedlings as compared to control, and the retardation effect increases with the increase of extract concentration. Relatively, root growth was more affected than that of shoot due to weed extract. In this study, 2% of S. articulatus weed extract showed high inhibitory effect on shoot height, root length, fresh weight and dry weight comparing to the other weed extracts. In addition, the total chlorophyll, total soluble protein, phenol, and hydrogen peroxide concentration significantly reduced due to weed extract compared to controls. Comparatively, the highest growth inhibition in rice was observed due to S. articulatus followed by E. congesta and P.hysterophorus. These findings may provide useful information for the management of rice field from adverse allelopathic effect.
A Sat, study studied this question.