Abstract: The correlation between the occurrence grade of the over-summer stripe rust of wheat and the key meteorological factors in the East of Gansu Province was analyzed.The results showed that the occurrence grade of the over-summer stripe rust of wheat was related to the temperature,precipitation,sunshine and relative humidity.The temperature in August,the precipitation in July and the relative humidity in August had significant impacts on the occurrence grade of the over-summer stripe rust of wheat.The ten days average temperature in the last ten day of July and the last ten days of August,the total precipitation in the last ten day of July and the last ten days of August,and the relative humidity in the last ten day of July and the last ten days of August were the key factors and critical period which affected the occurrence grade of the over-summer stripe rust of wheat.Based on the above results,a prediction equation for the occurrence grade of the over-summer stripe rust of wheat was established.The occurrence grade of the over-summer stripe rust of wheat for 2006 and 2007 was forecasted and the results was well accorded to the investigation results by the local plant protection station.

Key words: Over-summer stripe rust of wheat, Over-summer stripe rust of wheat, Grade forcast, Key meteorological factor