Effect of density and nitrogen on seed quantity and quality of winter rapeseed in Hamedan conditions

Effect of nitrogen (0, 40, 80, 120 and 160 kg N ha-1) and plant density (40, 60 and 80 plant m-2) on yield, yield components, grain quality and chlorophyll index of rapeseed was investigated as a factorial experiment based on randomized complete block design with three replications. The effect of nitrogen and density on all traits was significant. Maximum 1000-seeds weight, chlorophyll index and grain yield were obtained at 120 kg N but maximum oil percentage (46.63%) was revealed at 40 kg N. Mean comparison for density indicated that maximum 1000-seeds weight and chlorophyll index belonged to 40 plants density. Maximum oil percentage (45%) and grain yield (280 g m-2) were achieved at 60 plants density but there wasn’t significant difference between this treatment and 80 plants density for oil percentage and grain yield. Effect of treatments interaction on number of pods/m2, number of seeds/pod, biological yield and oil yield was significant. The highest biological yield (1320 g m-2) was obtained at 160 kg N and density of 80 plants. Maximum oil yield (158 g m-2) was also belonged to 120 kg N and density of 80 plants. It should be mentioned that this treatment had no significant difference with treatments of 120 kg N and density of 60 plants and 160 kg N and density of 60 plants. Therefore, it seems that density of 60 plants with consumption of 120 kg N ha-1 is suitable for producing maximum grain and oil yields of winter rapeseed.