عنوان مقاله [English]
Effect of different amounts of foliar- and soil- applied N were evaluated in a factorial arrangement of RCBD with three replications at the Agricultural Research Station of Gorgan in 2004-2005 growing season. Two promising lines of bread wheat, two levels of foliar application of nitrogen (0 and 5%) at tillering and booting stage, with five rates of 0, 45, 90, 135 and 180kg N/ha as urea were used. ANOVA results showed that grain and biological yield increased from 4130 and 9529 kg/ha to 5399 and 13400 kg/ha at 0 and 180kg N/ha, respectively. Foliar application of nitrogen did not affect grain yield of studied lines. Grain yield was not significantly affected by N foliar application, while it increased yield about 120 kg.ha-1. With increasing of N rate, spike length increased significantly. Increasing of grain yield due to soil-applied N might be attributed to increase in number of seeds per spikes.