بررسی آلودگی بیماری لکه خرمایی گندم در مزارع استان گلستان

Tan spot caused by Pyrenophora tritici-repentis (Ptr) is a destructive disease in wheat-producing areas in the world, especially in areas with conservation agriculture and no tillage. This disease has spread in the northern provinces of Iran in recent years, especially in rainy years. In order to study of infection situation of the fields in the province, disease evaluating was carried out in 300 fields in 14 cities of Golestan province during 2023-2024. 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 locations. Maximum of average incidence was observed in the west of the province in Bandar Turkmen (46.6%), Ramian (44.7%), Gorgan (42.1%) and Agh Qala (40.5%), and in the east of the province in Kalaleh (41 percent). Maximum of mean severity was recorded in Bandar Turkmen equal to 4.7% and Kalala 4.5%. It should be mentioned that in the year of study, drought stress and low rainfall reduced the incidence and severity of tan spot and other wheat disease compared to previous years. A total of 20 different varieties of rainfed and water common wheat in the province were monitored, and among the rainfed varieties, the highest average incidence of disease was observed in Kohdasht (56.9%), Line 17 (38.6%) and Qabous (30.8%). Line 17 and Kohdasht had the highest severity of the disease equal to 7.6% and 5%. In water cultivars, Ehsan, Kalate, Pishgam, Morvarid and Araz cultivars were evaluated with the highest occurrence and severity of the disease, and the lowest incidence and severity of the disease were recorded in DH, Noodle, Collector and Basilio cultivars.