evaluating the competitive ability of different common bean genotypes against the weeds

in order to investigate the effects of weeds interference on yield and yield components of different genotypes of common bean, an experiment was conducted as split plot based on randomized complete block design with three replications at agricultural research station of tabriz university, in 2011. the main plots were eight genotypes of different types of common bean including red bean, (cv. gholi, sayad, derakhshan and akhtar); pinto bean, (cv. khomein and sadri) and white bean (cv. shokufa and pak) and the sub-plots were two levels of weed including weed-free and weed-infested. results indicated that the effect of bean genotype was significant on yield and yield components. the effect of weed treatment was significant on all traits of common bean, except 100-seeds weight. the pod number per plant of all common bean genotypes reduced significantly under weed-infested treatment. the interaction effect of weed treatment× genotype was significant on bean seed number per pod, grain and biological yield. among the genotype, the cv. gholi had the highest pod number per plant and the cultivars gholi and shokufa had the highest seed number per pod. the cultivars of gholi and khomein produced the highest and lowest seed yield, respectively in both weed-free and weed-infested treatment. the common bean genotype showed different competitive ability as the genotypes gholi and pak had the higher competitive ability against the weeds than other genotypes. therefore by cultivating the bean genotypes with high competitive ability against the weeds, the yield loss of common bean could be reduced as well as the growth of weed species will be suppressed.