Effect of Spraying Urea on Winter Wheat, Triticum aestivum

The effects of different concentrations of urea (1 to 12%) sprayed at heading and blooming and after blooming on the components of yield, yield, crude and true protein, gluten, Ca, P, and niacin content of wheat, were studied over 3 years. Foliar application of urea caused an increase in the number of kernels per head and 1000-kernel weight. Concentrations beyond 3% eliminated mottling in grains altogether. Mottling was inversely related to die protein content. Concentrations from 1 to 6% increased the yield of grain irrespective of season and the yield response was linear when spray was given at heading, an increase of 52 pounds per acre (4% of that under check) having been recorded with each increase of 1% in concentration, the maximum increase being of the order 24%. Subsequent sprays were not beneficial. Urea sprays increased the proportion of grain in total dry matter produced. Spraying urea resulted in considerable increase in both crude and true protein contents, the response in protein to different concentrations being linear at all the three frequencies. Increase in total protein content was largely due to that in the true protein fraction. The range of increase in protein varied from 18 to 34%. Spraying after blooming was more efficient than at heading or at blooming for enhancing the rate of accumulation of protein in grain. Increases in protein yield per acre due to N sprays ranged from 24 to 60%. Increases in gluten followed the pattern of protein and were of the order of 53 to 70%. Gluten constituted 70% of crude protein and 80% of true protein in nonsprayed wheat and 82% of crude protein and 90% of true protein in N sprayed wheat. While ash and Ca contents remained unaffected P content increased on account of spraying urea. Foliar sprays of N increased the niacin content of grain.