In the present study efficacy of aqueous extracts of rhizome, stem and leaves of Zingiber officinale were studied on germination, growth and yield parameters of Vigna radiata. Seed germination and its associated parameters like vigour index, tolerance index, root and shoot length, fresh and dry weight were found to be decreased considerably as the concentration of stem and leaves extracts increased, when compared to control. Where as in rhizome extract the maximum values were observed in 10% concentration for all parameters when compared to control. On the converse the phytotoxicity was found to be increased in stem and leaves extracts as the concentration increased when compared to control. All the measured yield parameters like height of the plant, number of leaves per plant, number of branches per pant, number of pods per plant and number of seeds per pod were found to be decreased as the concentration of leaves and stem extracts increased when compared to control. On the other hand in rhizome extract the maximum values were observed in 10% concentration when compare to control and all other concentrations. In all the above parameters were studied the maximum and minimum values were recorded in control and 50% concentrations in stem and leaves extracts whereas in rhizome extract maximum and minimum values were recorded in 10% and 50% concentrations respectively.
Key words: Allelopathy, germination, phytotoxicity