Effect of sowing date and different intercropping patterns on yield and yield components of rapeseed (Brassica napus L.) and chickpea (Cicer arietinum L.)

In order to evaluate the effect of sowing date and planting pattern on yield and qualitative parameters of rapeseed (Brassica napus L.) and chickpea (Cicer arietinum L.) in intercropping, a split plot experiment was conducted based on randomized complete block design with four replications, in Hamedan, Iran, during 2014-15. The rapeseed seeds were sown on 21st September. Chickpea was sown on four sowing dates as the main factor (21 September, 10 October, 30 October and 20 November) with 20 days interval. The sub-factor was the planting pattern by replacement series including 100:0, 75:25, 50:50, 25:75 and 0:100 chickpea-rapeseed mixtures, respectively. Based on the results obtained, among chickpea sowing dates, the first and the last dates had the lowest and highest above-ground biomass and grain yield, respectively. During the late sowing date of chickpea (20 November) the field temperature was colder than the earlier dates, and therefore the freezing temperatures did not allow the seeds to germinate. However, no damage happened to seedlings with the earlier sowing dates. The highest yield was observed in sole cropping for both crops. In contrast, the highest values of land equivalent ratio were obtained in intercropping system. The highest value for land equivalent ratio was calculated as 1.23 in intercropping of 50% chickpea + 50% rapeseed.