NEW FUNGAL POTATO PATHOGENS: RESISTANCE TO FUNGICIDES

New pathogenic to potato fungal strains were found on potato tubers grown in the Kostroma and Moscow regions in 2018. These strains were isolated into axenic cultures and analyzed by cultural, morphological and molecular methods. They were identified as Ilyonectria crassa and Septotinia populiperda . The pathogenicity of these species has been proven by the Koch triad. The slices of potato tubers were inoculated with macroconidia of I. crassa and mycelium of S. populiperda . Mycelium from the slices were isolated into axenic culture. These fungal strains were completely identical to the parent strains. Previously, these species of fungi were not reported as potato pathogens. Resistance of I. crassa and S. populiperda to fungicides fludioxonil (preparation Maxim), azoxystrobin (Quadris), colloidal silver (Zeroxxe) and difenoconazole (Score) were tested. I. crassa was sensitive to Maxim and Quadris; S.populiperda to Maxim and Zeroxxe.