Interactive Effect of Zinc Fertilization and Cultivar on Yield and Nutritional Attributes of Canola (Brassica napus L.)

Zinc (Zn) is an important micronutrient for plants, but mostly, soils do not have enough amounts of Zn available. This necessitates the application of supplementary Zn for proper growth and development of plants. Canola is an important oilseed crop of the world, but its yield attributes, protein and oil contents, and fatty acid composition are always being investigated for improvement under various agroclimatic conditions, which was the major objective of this study. This 2-year field experiment was conducted to evaluate the efficiency of soil applied Zn and cultivars for yield attributes and seed oil quality of canola. Treatment included four canola cultivars viz., Faisal canola, Pakola, PARC canola, and Rainbow factorally combined with three zinc levels (0, 5, and 10 kg ha(-1)). Zn fertilization improved yield attributes and yield of the canola cultivars, but cultivars differed in their response to Zn fertilization. Rainbow cultivar produced 24-27% higher seed yield at 10 kg ha(-1) Zn as compared with control treatment. In addition, Pakola cultivar attained 0.5-1.5% higher oil contents at 5 kg ha(-1) Zn when compared with the control treatment. However, soil applied 5 and 10 kg ha(-1) Zn did not show any significant influence on protein contents of all canola cultivars. Zinc fertilization increased the seed yield and yield components of canola cultivars and significantly enhanced the oil contents. Rainbow cultivar was found to be the most responsive to Zn fertilization regarding the seed yield and oil contents and its fatty acid composition and economic returns.