One of the main challenges of current agriculture to ensure food security is the development of strategies to deal with potential negative impacts and adaptation to climate variability. This study has conducted to determine climatic and management factors in§uencing wheat yield variability throughout a temperate region in Northeastern Iran in the period of 1980–2010. The growth stages and yield of wheat crop were simulated with DSAAT model, using AgMERRA gridded dataset and the effect of climatic variables on yield was identi¦ed using Panel Data Regression (PDA). According to the results, 63% of the changes in irrigated wheat yield are explained by environmental factors (temperature and precipitation) and 37% by management factors. PDA revealed that among the climatic variables, the number of temperatures above 30 oC during the growing season, mean temperature, amount and frequency of precipitation have a signi¦cant effect on irrigated wheat yield (p ≤ 0.05). The length of wheat growing season throughout the study region were decreased by 26 days during the study period. The management practices, including the provision of inputs such as chemical fertilizers, modi¦ed seeds, tillage machinery and equipment, information transfer and the penetration of knowledge in the ¦eld, increase yields by averaged if 5 kg per year in study region. In general, employing the effective management methods, in particular selecting the appropriate planting date that could be resulted in better adaptation of the phenological stages of wheat to environmental conditions, can improve wheat yield. The results of this research indicate that using valid AgMERRA meteorological dataset as input for DSSAT crop model could produce reliable simulations which in turn could be employed by food policy and decision makers, farmers and managers in a temperate region.

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