allelopathic effects of aqueous extracts of two crops (wheat and barley) and wild mustard (sinapis arvensis)

in order to study the interaction allelopathic effects of wheat, barley and wild mustard on seed germination and seedling growth, this investigation was conducted in 2009 in two separate experiments. allelopathic effect of four aqueous extracts (0, 2.5, 5 and 10%) of wild mustard on wheat and barley germination was evaluated in the first experiment, based on two randomized completely designs (rcd) with three replications. in the second experiment, the effects of barley and wheat aqueous extracts (0, 2.5, 5 and 10%) on germination and seedling growth of wild mustard were investigated in two separate experiments. results indicated that the extract concentrations of wild mustard reduced germination rate and seedling growth of wheat and barley, significantly. in the second experiment, effects of extract concentrations on seed germination and seedling growth of wild mustard was significant in 1% probability level. seed germination reduction of wild mustard under 2.5 and 5% extract concentrations compared to control, was 64 and 91% in wheat and 80 and 96.6% in barley, respectively. the germinations of wild mustard were terminated by 10w/v of all crop extracts. generally, results showed that the allelopathic effects of wild mustard on wheat were higher than barley. also, barley had higher allelopathic impact on wild mustard compared with wheat.