Abstract: Correlation analysis was performed between data about appearance of central infected plants, prosperous beginning stage, occurrence degree for sunflower Sclerotinia sclerotiorum in hetao irrigation district from 2000 to 2009 and meteorological data in corresponding period. And corresponding predictive equations were established. The results showed that, precipitation was the key factor for the occurrence of sunflower Sclerotinia sclerotiorum. And temperature, humidity, evaporation, gale days, sunshine duration also had significant impacts on the occurrence time and degree of the disease. Six forecast models for November and May of next year were established through the 0.05 level of significance test in use of stepwise regression, and historical materials fit better. There were small difference between the predicted value and the actual value by forecasting for 2010 and 2011, as a result, the forecast models could be put into operation.

Key words: Sunflower Sclerotinia sclerotiorum, Meteorological condition, Forecast methods