Allelopathic effects of <em>Parthenium hysterophorus</em> L. aqueous extracts on soybean (<em>Glycine max</em> L.) and haricot bean (<em>Phaseolus vulgaris</em> L.) seed germination, shoot and root growth and dry matter production

Abstract

Aqueous extracts of shoot (stem + branch), leaf, fl ower and root of Parthenium hysterophorus L. at 0, 5, 10 and 15% (w/v) concentrations were applied on seeds of soybean (Glycine max L.) and haricot bean (Phaseolus vulgaris L.) to investigate their effect on percent germination, germination rate, and seedling growth (shoot and root length) and dry matter production under laboratory condition. The treatments were laid out in a completely randomized design with factorial arrangement in four replications. The trial was conducted twice, November 13 - 26 and December 1 - 14, 2008. Results depicted that signifi cant (P < 0.01) difference between plant parts, concentration levels and their interaction for the aforementioned parameters. Aqueous extracts of fl ower at all concentrations, and leaf at 10 and 15% and shoot at 15% concentration levels 100% inhibited germination of both crops. In contrast, aqueous extracts from shoot and root at 5% had lower effect, while at higher concentrations greatly reduced germination percentage and growth of the crop. Roots of the crops were more sensitive to allelopathic effect than shoots. It is recommended that integrated weed management strategy should be designed and employed to combat the weed from soybean and haricot bean fi eld to avoid poor germination and seedling growth and ensure sustainable production of the crops.