Abstract

An experiment was conducted in the Assosa university farm during 2019 and 2020 on maize cultivars with the objective of calibrating and validating maize cultivar coefficients using DSSAT software version 4.7.5. Five-cultivar coefficient was calibrated and evaluated using 2019 and validated using the 2020 crop data. The Genetic coefficient among cultivar showed, SHONE is highest in grain filling rate, while SHONE, BH545 and MH138 are highest in delay in development due to photo-period sensitivity, and highest in the number of kernels. Normalized difference RMSE (nRMSE) was Zero for days to anthesis, days to maturity and grain yield, while it was between 0-20% for leaf number and dry biomass yield as calculated by DSSAT during calibration. Time serious crop growth showed higher R2 (>90) and d-stat (>85) for most measured crop parameters during validation. The calibration results of 2019 showed that the observed and simulated values of maize cultivars are similar with ratio of near 1, for at least five measured values: days to anthesis, physiological maturity, dry biomass yield, grain yield and unit grain weight. The sensitivity analysis also showed that the performance of the different cultivars can vary depending on the climatic condition that could occur in study site. The day of planting when changed, starting from May 1 through to May 10 and May 20 continuously, increased the grain and dry biomass yield, but yield on May 1 was lower compared to actual time of planting (June 1-15), while planting in June 25 decreased the grain and biomass yields. Under stress conditions improving the plant density between 9-12 plant per m2 and the date of planting to May 10 to 20 could increase the yield of maize cultivars. The more cultivar coefficients are well calibrated and validated the more the yield estimation of the DSSAT software.