Effect of different planting pattern of (rapeseed-broad bean) using replacement series method on yield performance of rapeseed and weed biomass

Abstract

A field experiment was conducted to evaluate the competitive effects of different densities of rapeseed-broad bean intercropping on weeds growth and rapeseed yield at Shoushtar Agriculture, University in 2014. The experiment was performed in a completely blocks randomized design with four replications using replacement series in which broad bean and rapeseed were planted in different ratios of 100:0, 75:25, 50:50, 25:75 and 0:100 with a 20 bushes m–2. Weed dry weight and weed density were reduced in intercropping system compared to rapeseed and bean sole crops. The most reduction in weed dry mass occurred in 50:50 ratio of rapeseed-bean intercropping. By increasing the density of rapeseed the seed yields, the number of pods in plant, the number of seeds in pods and the weight of 1000 seeds were increased. Evaluation of relative yield was higher than 1 in all mixture ratios. Based on competition indices rapeseed was of a less competitive ability than broad bean. Also, there was a significant negative correlation observed between broad bean density and rapeseed yield components which implies that a high density of broad bean up to 25% can cause serious yield reduction in rapeseed.