Effect of foliar spray of urea on the growth and yield of wheat (Triticum aestivum L.)

The soil of experimental area was clayey in texture, non-saline (EC 0.29 and 0.31 dSm-1) at upper and lower depths, moderately alkaline in reaction (pH 7.86 and 8.18) at both depths, poor in organic matter (0.85% at 0-15 cm and 0.65% at 15-30 cm) and total nitrogen (0.046% at 0-15 and 0.035% at 15-30 cm) respectively. The available phosphorous (3.96 and 2.00 mg per kg) was low and exchangeable potassium (194.25 and 145.25 mg per kg) at 0-15 and 15-30 cm depths was high. The effect of foliar spray of urea on number of productive tillers at maturity, plant dry weight at ear head emergence, grain yield and biological yield were significant at P 0.05 level of significant by LSD. Whereas the plant height at ear head emergence, maturity stages, number of tillers at ear head emergence, length of ear head, seed index, straw yield, harvest index were non-significant with foliar spray of urea. However, 75 kg N per ha + 2.5% foliar spray of urea increased growth, yield and yield components of wheat as compared to 150 kg N per ha soil as well as 1.0% and 2.0% of urea through foliar spray. The foliar application of urea significantly increased the nitrogen content in plant at tillering, ear head emergence, straw and grain as compared to soil application. Also significant increase in crude protein content in grain was determined, but non-significant effect on phosphorous and potassium concentrations in plant at tillering, ear head emergence, straw and grain was observed. Foliar application of urea significantly increased the nitrogen uptake in plant at ear head emergence, straw and grain, whereas phosphorous uptake at tillering, ear head emergence and in straw was non-significant, as well as potassium uptake at tillering was non-significant. However, slight increase was obtained with 75 kg N per ha + 2.5% foliar spray of urea. The data regarding value cost ratio (VCR) was higher (5.13) in case of 75 kg N per ha + 2.5% foliar spray of urea, while lower VCR (4.28) was determined with 150 kg N per ha soil application. From the above findings it is concluded that combined application of nitrogen fertilizer of 75 kg N per ha with 2.5% foliar spray of urea is beneficial and economical for wheat crop. It is also suggested that more research may be conducted to find out the beneficial and economical level of N fertilizer with foliar spray of urea.