Sclerotinia stem rot of canola in Golestan province

Sclerotinia stem rot (SSR)، caused by Sclerotinia sclerotiorum، is the most important disease of canola (Brassica napus). This disease has been observed in different regions of Golestan province since the first years of canola planting. In order to study of infection situation of the fields in the province، disease evaluating was carried out in 80 fields in four locations (Gorgan، Ali Abad، Kalaleh and Gonbad) during 2006 and 2007. Statistical analyses of disease data were performed based on disease incidence (I) and mean severity (S) of the fields. The results revealed that the incidence (P=0. 05) and severity (P=0. 02) are significantly different in the four locations. Minimum and maximum of average incidence was observed in Kalaleh (10. 7%) and AliAbad (22. 11%)، respectively، but Minimum and maximum of mean severity was recorded in Gonbad (5. 6%) and Ali Abad (17. 2%)، respectively. Minimum and maximum of disease incidence was observed in Gorgan in 2006 (1%) and Ali Abad in 2006 (81. 5%)، respectively، that were equivalent to 0. 6% and 66. 75% disease severity.