effect of sowing date and plant density on yield and yield components of cow pea (vigna sinensis l.) in ahwaz

sowing date and plant density are important factors in grain yield of cow pea. in order to study effect of sowing date and plant density on yield and yield components of cow pea, an experiment was conducted in research farm of ramin university of agricultural and natural resources in 2008. the experimental design was split plots in randomized complete design with four replications. the experimental factors were sowing date (7 jun., 22 jun., 7 jul. and 22 jul.) in main plots and inter row spacing (10, 15, 20 and 25 cm) in sub plots. the results showed that sowing date had significant effect on all of traits, in the other hands, inter row spacing had significant effect on number of pods in plant, number of grains in pod and grain yield, but had not significant effect on 1000 grain weight and harvest index. interaction effect of sowing date and inter row spacing was significant only for grain yield. also, comparison of means showed that with delay in sowing date and increase of inter row spacing, decreased the grain yield.