Effect of sowing density and growth habit on yield, yield components and weed community of common bean (Phaseolus vulgaris L.)

To investigate the effect of sowing density and growth habit on yield، yield components and weed community of red bean an experiment was conducted at Research Farm of Zanjan University، during 2009. The experiment carried out using factorial-split plot design in completely randomized block arrangement with three replications. The main plots، included three red bean cultivars (Goli، Sayyad and Derakhshan) and plant density at two levels (40 and 66 plants. m-2) as a factorial and sub plots included weed competition at two levels (weed control and without control)، respectively. Goli and Derakhshan cultivars produced 12 and 10%more grain yield than Sayyad cultivar، respectively. Also، results showed that the effect of sowing density on the number of pods per plant (15% reduction)، number of seeds per pod (8% reduction) and grain yield (5% increasing) was significant and on other traits were not significant. According to the results weed infestation reduced red bean grain yield about 35% compared to control. Goli cultivar caused a reduction in total weed density (2 times more reduction than Derakhshan cultivar) and dry weight (about 3 times more reduction than Derakhshan cultivar) compared to other cultivars; also increasing sowing density decreased total weed density (32%) and weed dry weight (22%)، significantly.