Nitrogen Application Enhances the Radiation Use Efficiency and Quality of Cotton (Gossipum Hirsutum L.) Under Divergent Agro-Ecological Conditions of Pakistan

Cotton being a cash crop plays a pivotal role in the economy of Pakistan. Climate change has a pronounced impact on radiation use efficiency and quality of cotton fiber. To find out how nitrogen affected the radiation use efficiency and fiber quality of cotton cultivars in Punjab, a field study using a split-plot design was carried out. The study under representation was conducted in three different locations over the course of two years (2016 and 2017): Adaptive Research Farm in Dera Ghazi Khan, The Regional Agriculture Research Institute, Bahawalpur and The College of Agriculture, University of Sargodha. Three cotton cultivars viz., FH-Lalazar, FH-142, and MNH-786 were treated to six different nitrogen levels (0, 60, 120, 180, 240, and 300 kg ha-1) at each of the experimental location. The data collected from the experiments were used as input to run the CROPGRO-model. Input data from 2016 and 2017 were used to calibrate the CROPGRO-cotton model, and its evaluation involved comparing the simulated and observed values. This model accurately predicted radiation use efficiency, cotton fiber quality, and nitrogen impact on three cotton cultivars. For cotton productivity, the arid climate of Bahawalpur is far superior to the semi-arid climates of Sargodha and Dera Ghazi Khan, Pakistan.