Abstract:To test BarleyGrow model reported in the study I, 14 barley cultivars were grown at different sowing dates in 4 ecological areas (Nanjin, Yangzhou, Wuhan and Kunming). Apical and phenological stages of different cultivars were observed to validate the BarleyGrow model which is compared with YDmodel and SUCROS. The optimum values of the model parameters were obtained through genetic-simulated annealing algorithms. As a whole, BarleyGrow model had an accurate and stable estimation. The root mean square error (RMSE) with the BarleyGrow model was ranged between 1.06 and 8.13 days for various cultivars, compared to 6.26 and 13.35 days with YDmodel, and 8.84 and 20.28 days with SUCROS. BarleyGrow model was quite sensitive to basic temperature in grain filling time, physiological vernalization time, critical daylength and minimum time from emergence to heading. The improved model gave good predictions of apical and phenological development for a diverse range of temperature and photoperiod conditions across China. Especially, effects in anther separation, pollen mother cells, tetrad, heading, grain filling and maturity stages were better predicted.