Effects of S, B, Zn, and their interaction on quantitative and qualitative yields of rapeseed as second crop in the paddy field

In order to the effects of elements zinc, boron and sulfur on quantitative and qualitative agronomic characteristics of rapeseed var. Hyola 401, an experiment was conducted in Rice Research Institution of Iran, Rasht province in 2010. A field experiment with completely randomized block design was performed with eight treatments in three replicates. Treatment consisted of control, Zn, B, S, Zn+S, Zn+B, B+S, and S+B+Zn. Sulfur treatment was added at the rate of 100 kg ha-1 before sowing; Boron was added as Borax (Na2B4O7, 10H2O) at the rate of 1.5 kg ha−1, and zinc was added as Zn 15% EDTA at the rate of 1.5 kg ha−1 to the soil. Analysis of variance showed that the effects of treatments on siliques total number at plant, grain number at siliques thousand-seed weight and seed yield were significant (P<0.01). Minimum grain oil and seed yield were obtained from control treatments and the highest seed yields were obtained from S+B+Zn treatments. The maximum oleic acid (229.6 mg g-1) and linolenic acid (27.14 mg g-1) were obtained from B+Zn+S treatment. Maximum of linoleic acid (55.55 mg g-1) were obtained from B+Zn treatment. Maximum stearic and palmitic acid was obtained from B+Zn and S+Zn treatments which were 6.527 and 15.47 mg g-1, respectively. The highest erucic acid content was (0.878 mg g-1) at control treatment. Based on the results, application of B, S and Zn fertilizers with NPK fertilizer can help increase the yield and yield components in rapeseed.