Studies on the Effects of Climatic Factors on Dryland Wheat Grain Yield in Maragheh Region

In order to study the effects of climate variables on rainfed wheat grain yield, climate data and wheat yield for 10 years (1995-2005) collected from Dryland Agricultural Research Institute (DARI) in Maragheh as the main station in cold and semi-cold areas. Collected data were analyzed by correlation coefficient, simple regression, stepwise regression and path analysis. The results showed that relationships between grain yield with average relative humidity and total rainfall of growing season was positive and significant at 5% and 1% probabilities, respectively. However, evaluation between grain yield with sunny hours and class A pan evaporation was negative and significant