effect of sowing date and weed interference on yield and yield components of red bean (phaseolus vulgaris l.) cultivars with different growth habitat

sowing date is the most important factor in physiological and morphological characteristics with positive effects on plants. to evaluate the effect of sowing date and weed interference on yield and yield components of red beans cultivars a factorial split plot experiment in randomized complete block design with three replications was carried out in the research field of zanjan university. main plots included combinations of three levels of red bean cultivars (standing cultivar, derakhshan; semi standing cultivar, sayyad; prostrate cultivar, goli) with sowing dates at two levels (30th of may and 13th of june). subplots included weed interference at tow levels (weed infested and weedy check). analysis of variance showed that the difference of cultivars in most traits were significant. the weed interference had a significant effect on all traits except for seed weight and harvest index. sowing date was not significantly different in all traits. goli and derakhshan cultivars had the highest grain yield and total dry matter per hectare with quantities of 1188 and 3462 kg per ha, respectively. weed decreased grain yield and dry matter to half. goli cultivar in the first sowing date had the highest weed density and dry weight at the end of season. the highest weed density and dry weight also contributed to broadleaved weeds. it was concluded that the goli cultivar, due to higher performance in both sowing dates and weed interference condition was the best candidate for cultivating in zanjan.