NITROGEN APPLICATION IMPROVED NITROGEN USE EFFICEINCY, PHOTOSYNTHETIC CHARACTERISTICS AND YIELD COMPONENTS OF FIELD GROWN WINTER WHEAT

摘要

Grain yield response to nitrogen nutrition has been well examined, but dynamics of total biomass, nitrogen use efficiency, photosynthetic rate and chlorophyll contents of winter wheat in response to N nutrition are not well understood. The study was planned to investigate the effects of the different nitrogen fertilization levels on photosynthetic parameters, N use efficiency, and growth and yield traits of winter wheat. The treatments comprised of seven nitrogen levels viz; 0 kg ha-1,75 kg ha-1, 100 kg ha-1, 150 kg ha-1, 200 kg ha-1, 225 kg ha-1, and 300 kg ha-1. Nitrogen nutrition expressively enhanced growth, biomass production, and yield components of winter wheat plants. Results revealed that 225 kg ha-1 nitrogen significantly improved the growth and biomass characteristics by 11-120% than control. Similarly, in contrast to control, 225 kg ha-1 augmented the photo synthetic rate and total chlorophyll by 20% and 50%, respectively. Winter wheat under 225 kg ha-1 had significantly 149% and 54% higher nitrogen uptake and use efficiency than other treatments. Moreover, Nitrogen nutrition with 225 kg ha-1 demonstrated the maximum grain yield (6404.50 kg ha-1) and leaf area index (17.52) of winter wheat crop. Grain yield of winter wheat had a significant positive correlation with N uptake, N use efficiency, chlorophyll contents, and growth components. However, the negative relationship of grain yield was perceived with the photosynthetic rate. The results of the present study concluded that cultivation of winter wheat with high rate at 225 kg N ha-1 was remarkably beneficial with most favourable agronomic performance and grain yield as related to control.