Performance of Canola (Brassica napas L.) Seed Yield, Yield Components and Seed Quality under the Effects of Four Genotypes and Nitrogen Fertilizer Rates

This study was conducted at the Agricultural Research Station, Hada El-Sham, King Abdulaziz University during 2006 and 2007 seasons. Four canola varieties, Callypso, Pactole, Sero-4 and Sero-6 varieties were tested under four nitrogen fertilizer rates (0.00, 92,138 and 184 kg N/ha) to determine the effect of nitrogen fertilizer on the canola (Brassica napus L.) seed yield, yield components and seed quality. The results showed that as nitrogen fertilizer rate increased, plant height, number of fruit / plant, 1000-seed weights, seed weight / plant and protein content increased. However oil content (%), was the highest under 92 kg nitrogen rate, then significantly decreased under the higher nitrogen rates. In terms of variety differences, the plant height data revealed that Sero-4 was the taller, followed by Sero-6, and then Callypso and Pactole varieties and Pactale and Sero-6 varieties produced the highest number of fruits / plant and significantly dominated over the Sero-4 and Callypso variety. In addition, Pactale and Sero-4 had the highest 1000-seed weights without significant differences between them, while Callypso variety was the lowest. Pactole variety was also the highest in seed weight / plant, while Sero-4 and Sero-6 varieties were not significantly different in seed weight / plant. Pactole variety was the highest in protein content followed with a significant difference by Sero-4, then Sero-6, while the lowest variety in protein content was Callypso variety. The rate of 138 kg N / ha produced the highest seed yield / ha (1550.51 kg), protein content (28%) and had 34.10% oil content. Oil content of the studied varieties ranged from 37.80% for Callypso variety to 32.04% for Sero-4 variety, and the statistical comparisons showed significant differences among the four studied varieties. Furthermore, iodine value and refractive index of the oil under the effects of nitrogen fertilizer rates were not significantly different from