Effects of nitrogen and sulfur on growth, seed yield and quality in winter canola

Nutritional requirement of nitrogen (N) and sulfur (S) in canola is vital because of high protein and oil contents. Research information on quantitative requirement of N and S for winter canola in the southeastern US is needed. Therefore, field experiments were conducted to determine the effect of four N (57, 114, 171, and 228 kg ha⁻¹) and four S (0, 11,22, and 33 kg ha⁻¹) rates on canola yield parameters, quality of canola crop for two crop growing seasons and seed yield for three growing seasons. Results showed that N and S rates significantly influenced number of pods per plant and seed yield during both growing seasons. In 2004, application of 228 kg N ha⁻¹ and 33 kg S ha⁻¹ produced highest seed yields of 3205 kg ha⁻¹ and 3259 kg ha⁻¹ respectively. Interaction of nitrogen and sulfur rates on yield was not significant. The percent oil content decreased with increase in rates of nitrogen and was highest (39.04%) with application of 57 kg N ha⁻¹. Sulfur rates did not influence protein and oil content, but increase in N rates significantly increased protein content in canola during both growing seasons.