Effect of Nitrogen Rates and Time of Application On Growth, Yield and Quality of Canola.

Amongst the major nutrients, nitrogen (N) plays an important role in growth and development of field crops like canola. Balanced and timely application of N is one the most important strategies for realizing full potential of canola. Studies were carried out to determine the optimum rate and time of N application for canola in Faisalabad (31°.25 N, 73°.09 E), Pakistan. Five levels of N (0, 30, 60, 90 and 120 kg ha^-1) were maintained at  four growth stages viz. full N as a basal dose, ½ N as a basal dose + ½ N at branching, ½ N as a basal dose + ½ N at flowering and ½ N at branching + ½ N at flowering. Leaf area index (LAI), total dry matter (TDM), crop growth rate (CGR), seed yield, oil yield and protein content were significantly affected by rates of N and time of application. Highest level of N (120 kg N ha^-1) improved the CGR, seed yield, oil yield and protein content of canola when applied in two splits (½ N as a basal dose + ½ N at flowering).  67.28% higher seed yield was observed when N was applied @ 120 kg N ha^-1 over unfertilized control.
Key Words: canola, nitrogen, growth, seed yield, oil yield, protein content