Immunological assessment of winter barley cultivars against leaf net blotch

   Immunological assessment of winter barley varieties sown in the south of Russia in relation to leaf net blotch infestation for further use in agricultural production has been carried out. Barley net blotch is dominant in the pathologic complex of barley diseases worldwide. The pathophysiological processes of infection development depend on the type of resistance of the variety. Net blotch on resistant varieties is noted as small dark rounded spots. Infection often occurs as a result of mechanical damage to the leaf plate. The symptoms of net blotch disease on a susceptible variety have a characteristic reticulate pattern with pronounced necrosis and extensive chlorosis. One of the main ways to protect crops from the disease is the cultivation of resistant varieties. The study was conducted during the  growing seasons of 2020–2022 on artificial infectious background in the sprouting phase phase of the vegetation experiment and in the adult plant on the natural infectious background in field conditions. 10 varieties of winter barley of domestic and foreign selection were selected. Immunological assessment in the sprouting phase revealed two varieties resistant to leaf net blotch, score: Vivat (1.7) and Kvant (1.6); the varieties Artel (3.8), Fox-1 (2.3) of domestic selection and Carioca (2.7) of foreign selection showed moderate resistance. Field moderate resistance was detected in four winter barley varieties, %: Vivat (18.3), Kvant (26.6), Marusya (19.9), Fox-1 (24.9). Immunological assessment of barley varieties recommended for sowing in the south of Russia is one of the main components in the strategy of increasing the efficiency of plant protection measures and improving the ecological component of crops.