Investigation the effect of drought tension and plant density on quality and quantity characteristics of rapeseed (Brassica napus L.) cultivars in Lorestan climate conditions

In order to investigate the effects of drought tension and plant density on quality and quantity characteristics of Brassica napus L. cultivars, this experiment was conducted as split-split plots in randomized complete blocks design with four replications in Boroujerd Agricultural Research station in 2009-2010 cropping year. In this experiment, the drought tension was investigated in three levels included without tension (control), irrigation cut in the stages of after rosette and before flowering initiation and irrigation cut in the stages of after rosette, before flowering initiation and filling pod in the main plot and plant density in three levels 6, 10 and 14 kg consumed seeds in hectare in the sub-plot and cultivars of Brassica napus L. included Zarpham, SLMO46 and Okapi in the sub-plot. The results showed the effect of drought tension, plant density and their interaction on quality and quantity characteristics of Brassica napus L. cultivars was significant. The highest oil and grain yield was obtained in the treatment of irrigation cut in the stages of after rosette and before flowering initiation and seed density 10 kg/ha in Zarpham cultivar that seems it is related to 1000-grain weight, the number of pod in plant, harvest index and its more oil percentage. Zarpham cultivar was the most appropriate cultivar in the drought tension conditions and by investigating all of the indices, it was the best cultivar in usual conditions and had minimum yield reduction in tension conditions.