Effect of Sowing Date and Nitrogen Fertilization Level on Growth and Productivity of Some Durum and Bread Wheat Varieties

Two field experiments were conducted during the winter seasons of 2013/2014 and 2014/2015 at the Agricultural Research Station, Faculty of Agriculture, Alexandria University, Egypt, to study the response of two durum (Sohag 3 and Karim) and two bread (Misr1 and Casino) wheat varieties to three sowing dates (November 1st, November 15th and December 1st) and two nitrogen fertilization levels (95.2 and 190.4 kg N/ha). The experimental design was a split- split plot, with five replications, and the main, sub-and sub-sub- plots were assigned to sowing dates, nitrogen levels and varieties, respectively. The November 15th sowing date was the most suitable sowing date which gave the highest values for phonological characters and grain yield and its components, whereas, December 1st showed an apparent increase in grain protein content, compared to the two other sowing dates. Increasing N fertilization level from 95.2 to 190.4 kg N/ha significantly increased all phonological traits, grain yield and its components and grain protein content characters. Misr1 variety was superior to the other cultivars in phonological characters and grain yield and its components, except for the number of spikes/m^2, harvest index and protein content where Sohag 3 showed significantly higher values than the other varieties. The three-factor interaction was insignificant, while, the twofactor interactions, D*N, V*D and V*N were significant for different characters in the two seasons. The best combination of the three factors for grain yield was Misr1, sown on November 15th and fertilized with 190.4 kg N/ha.