Improvement of the protection system of large-seeded sunflower against diseases

The main purpose of the work was to improve elements of the protection system of sunflower seeds and plants against diseases. A system of protective measures was tested, including tank mixtures of fungicides of biological and chemical origin and agrochemicals against a complex of the most common harmful diseases on large-seeded sunflower variety Karavan bred at VNIIMK. The choice of fungicides for pre-sowing seed treatment and sunflower vegetation treatment was based on previously obtained data, which showed the best result in the laboratory conditions. The research was conducted at the V.S. Pustovoit All-Russian Research Institute of Oil Crops (VNIIMK) in 2022 and 2023. The determination of biological efficiency and yield was carried out according to the generally accepted methods of VNIIMK and VISR. The main diseases on sunflower during the years of the research were downy mildew, alternariosis, bacteriosis and phomopsis. The combined use of an insecto-fungicidal tank mixture Scarlet, OE (imazalil, 100 g/l + tebuconazole, 60 g/l), 0.4 l/t + Apron XL, WE (mefenoxam, 350 g/l), 3.0 l/t + Potassium humate, 2.0 l/t + Kruiser, EC (thiamethoxam, 350 g/l), 8.0 l/t, followed by double treatment according with Mystery, OE (diphenoconazole, 40 g/l + pyraclostrobin, 80 g/l + tebuconazole, 80 g/l), 1.0 l/ha during the vegetative period allowed not only to reduce the prevalence of the main pathogens in the crop, but also to obtain the largest amount of saved yield - 0.60 t/ha.