Analysis of Temperature and Rainfall Characterteristics on the Attacking Date of Sunnpest in Isfahan Township

Sunnpest is the main pest of wheat and it is the most important plant medical problems in Iran. In this research, we analyzed the relationship between temperature characteristics (Min, Max, Ave Tem Peratmre, as wall as the number and degree of frost), precipitation and drought-wet years with attacking date in Isfahan during the years 1999-2000 to 2009-2010. The research results showed that the attacking date of sunnpest is depended on the climatic conditions before attacking date of the pest. If the Autumn and Winter temperatures at are higher than the average temperature, and S.P.I. indices are normal, the sunnpest attacking date begins to take place sooner. There is a strong and significant correlation between the yearly and seasonal frost numbers, different frost thresholds, minimum, maximum and average temperature, and the attacking dates of sunnpest at 0.05 and 0.01 significant levels. The R2=97 % shows that 97% of variance depended variable (attacking dates of sunnpest) corresponds with the independed variables (min. and max. temperature, total precipitation during the cold period (Autumn and Winter), and the number of annual frost). This shows that these parameters are important in predicting the attacking date of sunnpest in the regression model.