Abstract To account for the effect of water stresses in the various growth stage, the multiplicative, seasonal and minimal approach are integrated in the model. To evaluate the model, the simulated yields for winter wheat under various levels of water stress were compared with observed yields. The result showed, simulated crop yields agreed well with observed yields for this location using multiplicative approach. The correlation coefficient (R2) between observed and simulated yields ranged from 0.81 to 0.92 with very high modeling efficiencies. The root mean square error (RMSE) values are relatively small and ranged between 6 to 14%. The seasonal and minimal approaches performed significantly less accurately in the Sharif Abad district. A sensitivity analysis showed that the model is robust and that good estimates can be obtained by using indicative values for the required crop and soil parameters. The minimal input requirement, the robustness of the model and its ability to describe the effect on seasonal yield of water stress occurring at particular moments in the growing period, make the model very useful for the design of deficit irrigation strategies. Keywords: aquacrop, Seasonal approach, Minimal approach and Multiplicative approach. پرونده مقاله