Evaluation of Seed Yield and Micro Nutrients Content in Seeds of High Yielding Rapeseed (Brassica napus L.) Varieties as Affected by Nitrogen Sources

To select high yielding rapeseed varieties, at the first phase of research, two field experiments were performed in 2006-2008 cropping seasons at experimental field of Agricultural and Natural Resources Research Center of Markazi Province, Arak (34? 5´ N; 49? 42´ E, and 1708 m above sea level), Iran. In this research, 15 winter rapeseed varieties were compared in a randomized complete block design with three replications. Results showed that Licord, Modena and Okapi varieties had the greatest seed yield, respectively. At the second phase of research, two experiments carried out during 2008-2010 cropping seasons at the same site in order to assess the effects of nitrogen sources on yield and micro nutrient contents in seeds of selected high yielding Rapeseed (Brassica napus L.) varieties. Experimental design was a factorial arrangement based on randomized complete block with three replications. Three rapeseed varieties (V1: Okapi, V2: Modena and V3: Licord) and three sources of nitrogen (N1: Azocompost, N2: 50% Azocompost plus 50% Urea and N3: Urea) comprised the experimental factors. In this research, Licord variety showed the highest seed yield and the greatest ratio of Iron (Fe), Zinc (Zn), Copper (Cu) and Manganese (Mn) in seeds. Integrated nutrition system and Licord variety showed superiority for seed yield, content of Cu and Mn to other treatments. In general, integrated nutrition system enhanced seed yield per unit area and micronutrient content in seeds of rapeseed.