Seed yield and macro nutrients content comparison in 15 varieties of winter rapeseed as affected by sulphur utilization

In order to compare the seed yield of 15 winter rapeseed (Brassics napus L.) genotypes, a field experiment were performed in 2006-7 and 2007-8 cropping seasons in Agricultural and Natural Resources Research Center of Markazi Province, Arak, Iran. Rapeseed genotypes were compared in a randomized complete block design with three replications. Means comparison showed that Licord (3795 kg ha-1), Modena (3655 kg ha-1) and Okapi (3277 kg ha-1) genotypes had the highest seed yield, respectively. In the second phase of this research, in order to evaluate the effects of sulphur (S) rates on seed yield and accumulation of macro nutrient in seeds of high yielding rapeseed genotypes, a field experiment carried out as factorial arrangement based on randomized complete block design with three replications, during 2008-9 and 2009-10 cropping seasons at the same site. Treatments were three rapeseed varieties (Okapi, Modena and Licord) and three rates of sulphur (0, 40 and 80 kg ha-1).The interaction effect between sulphur*variety was significant for seed yield and other measured traits. The combination of 40 kg ha-1 Sulphur*Okapi showed the highest seed yield and seed nitrogen content. Greatest seed phosphorus and potassium content was observed in Modena cultivar and S2 treatment (40 kg S ha-1). Licord cultivar showed the highest ratio of seed sulphur content at control and different rates of sulphur utilization in comparison with other vareties. In general, it is presumed that utilization of 40 kg S ha-1 can enhance seed yield and seed macro nutrient content, related to rapeseed genotype.