Response of Three Bread Wheat to Nitrogen Fertilizer with or Without Ascorbic Acid Grown on a Clay Soil

A field experiment was conducted at Bahtim Agricultural Research Station Farm during 2012/2013 and 2013/2014 seasons. The experimental site is located at lat. 30.80, long 31.16 and 14.00 m above the mean sea level.The objective of this study was to evaluate the effect of nitrogen fertilizer rates (40, 60 and 80 kg N fed-1, with or without foliar application of ascorbic acid) on maximizing wheat yields and its attributes and grain quality of three wheat cultivars as a main-plots. The Egyptian bread wheat cultivars were Misr1, Misr2 and Gemmiza11. The experiment was designed in a split plot design with three replicates. The results indicated that: The highest significant value of spike number m-2 was noticed when wheat cultivar Mesr1 was planted compared to other bread wheat cultivars in both seasons. Also, 1000 grain weight and N uptake by wheat were significantly increased by planting Misr2. The number and weight of grain spike-1 were significantly increased when wheat cultivar Misr1 or Misr2 were planted compared to Gemmiza11 in the first season and vice versa in the 2nd one. Cultivar of Misr2 gave higher grain, straw, biological yield and harvest index as well as N, P and K uptake in grains than other cultivars in the first season only. Meanwhile, the grain, straw and biological yield as well as N, P and K uptake of wheat straw were significantly improved by planting Misr1 compared to the other cultivars in the second season. Also, data reveal that the planting of Misr1 and Gemmiza11gave the highest increase of N, P and K uptake of grain and biological yield compared to Misr2 in the second season only. Generally, in most cases, application of both nitrogen level (80 or 60 kg Nfed-1) with ascorbic acid gave the highest significant values of most yield components, grain, straw, biological yield and harvest index as well as N, P and K uptake of grain, straw, and biological as well as protein % in grain compared with other treatments in both seasons. Over all, the application of 80 or 60 kg N fed-1 with ascorbic acid to any bread wheat cultivars gave a significant increase of wheat yield components, grain, straw biological yield and harvest index as well as N, P and K uptake in grains, straw and biological and also protein % of grain in both seasons.