Calibration of CERES-Maize model and study of thermal requirements of Sweet corn under Tarai region of Uttarakhand
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Date
2020-12
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G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand)
Abstract
The present study was conducted at the Norman E. Borlaug Crop Research Centre of G.B Pant University of Agriculture and Technology, Pantnagar during kharif 2019 to analyze the effect of different sowing dates and nitrogen levels on the growth and development of Sweet corn as well as to study the thermal requirements of the crop in Tarai region of Uttarakhand. The experiment with two factors; sowing dates (8th August, 23rd August and 7th September) and nitrogen levels (150 kg N ha-1, 120 kg N ha-1, 90 kg N ha-1 and 60 kg N ha-1) was laid out in Split Plot Design with three replications keeping the sowing dates in main plot and nitrogen levels in sub-plot. The variety taken for the experiment was Sweet corn hybrid Sweet 77. All recommended cultural practices were followed during the crop growth period. The various growth parameters under observations were periodically recorded to evaluate the treatment effect on the growth and yield of crop. The heat unit requirement study shows that the various thermal indices i.e., GDD, HTU, PTU and HUE reduced with delay in planting dates. Higher values of thermal units were positively
correlated with good crop growth parameters and higher grain production. Experimental analysis suggests that the crop sown on 8th August with 120 kg N ha-1 performed better among all the treatments. The growth parameters such as crop height, leaf area
index and dry matter accumulation were at par in N1 (150 kg N ha-1) and N2 (120 kg N ha-1) treatments. The yield contributing parameters and grain yield were found to be reducing with delay in sowing date and lowering nitrogen doses. The CERES-Maize model was satisfactorily calibrated against the emergence (DAS), anthesis (DAS) and dry matter grain yield. The simulated dry matter grain yield was comparable with the actual observation with R2 of 0.96 and % RMSE of 9.14. Maize crop is grown throughout the country according to the climatic suitability. Weather variables play an important role in deciding the crop growth and productivity. The sensitivity analysis of the CERES-Maize model was performed to see the effect of the changing weather variables i.e., mean air temperature (°C), CO2 concentration (ppm) and solar radiation (MJ m-2 day-1) on the dry matter grain yield production of the crop. The results showed that the crop was highly sensitive to the changes in mean air temperature and solar radiation and responded differently under different growing environment. The simulated grain yield increased with increase in CO2 concentration and vice-versa.