Abstract: Based on the field experiments of two field experiment sites and the daily meteorological data of 11 meteorological stations evenly distributed in the winter wheat planting area of Guanzhong region in Shaanxi Province, the DSSAT model was used to determine the genetic parameters of winter wheat cultivars, and then the key phenological periods and yield of winter wheat at each station from 2001 to 2019 were simulated. The M−K test and the Sen trend analysis method were used to reveal the spatial and temporal evolution characteristics and laws from the station and regional scales. On this basis, the gray correlation method and multiple linear regression analysis method were used to explore the sensitive meteorological factors and their contribution rates affecting the simulated yield at each growth period. The results showed that: (1) the average RRMSE values of winter wheat flowering period, mature period and yield simulation results were 0.91%,0.98% and 7.87% in Yangling (Guanzhong Plain) field experiment site, and 2.39%,1.35% and 9.30% in Changwu (Weibei Dryland) field experiment site. In the regional phenological simulation, the RRMSE of winter wheat in the Guanzhong Plain and the Weibei Dryland were 3.2% and 3.0% at the flowering and mature periods, R² were 0.71 and 0.73, and the RRMSE of regional yield were 23.6% and 11.2%, respectively.(2) The sowing to flowering period and mature period of winter wheat in Wugong station showed a delayed trend, and the rates were 0.70d·10y⁻¹ and 0.22d·10y⁻¹, respectively, while the other stations showed an earlier trend. The advance trend of phenological period in Guanzhong Plain was higher than that in Weibei Dryland, and the advance trend from sowing to flowering period reaches 2.30d·10y⁻¹ and 1.20d·10y⁻¹ respectively, and the advance trend from sowing to maturity was 0.60d·10y⁻¹. The simulated yields showed a decreasing trend at Pucheng and Weicheng stations, while an increasing trend at other stations. The lowest and highest values of regional yield appeared in 2013 and 2017, respectively. (3) The increase of daily average temperature and daily minimum temperature in most stations would promote the increase of winter wheat yield in the pre-winter growth period. The increase of daily maximum temperature and total precipitation contributed greatly to the increase of yield in the overwintering period. The increase of daily maximum temperature at greening and heading period would lead to serious yield decrease of winter wheat, but the increase of daily relative humidity would promote the increase of yield. The increase of daily average temperature, daily minimum temperature and daily maximum temperature at most stations would lead to a decrease in winter wheat yield during the filling and mature period. Temperature was the main controlling factor affecting the yield of winter wheat in Guanzhong region, and its influence on yield varies greatly at different growth periods.

Key words: DSSAT, Guanzhong region, Meteorological factors, Phenological period, Winter wheat yield