SUSCEPTIBILITY OF DIFFERENT GRAPEVINE VARIETIES TO WHITE ROT ON DON AMPELOGRAPHIC COLLECTION
The paper summarizes the results of study of grapevine varieties affected by white rot on Don ampelographic collection. The white rot distribution is noted mainly in the southern regions with high humidity and frequent hail. Without protective measures, crop losses can be 20-50%, and in some cases up to 80%. The symptoms of the disease directly dependent on vegetative stage of berries - from the end of the period of herbaceous growth till veraison. Under conditions favorable for the disease spread, white rot can infect shoots, stems and leaves. Meteorological conditions during the growing season 2019, 2020 were favorable for the development of white rot. The highest intensity of white rot damage to vineyards in 2019, (more than 2.5 points), was found in the varieties: Tsimlyanskiy belyy, Sivolistnyy, Risling reynskiy, Sibirkoviy, Cabernet Sauvignon, Pukhlyakovskiy belyy, Olkhovskiy, Varyushkin. The development of white rot in 2020, despite the meteorological conditions favorable for its spread, was restrained by the use of Horus, VDG in herbaceous growth and veraison phases. Therefore, the intensity of white rot in 2020 in most varieties was absent or did not exceed 1 point. To the greatest extent (1.0 ... 1.8 points) the following varieties were affected by the phytopathogen: Tsimlyanskiy chernyy, Olkhovskiy, Neizvestnyy donskoy, Risling reynskiy, Krasnostop zolotovskiy, Bessergenevskiy №1, Silnyak, Durman, Bezymyannyy donskoy, Sibirkovyy, Cabernet Sauvignon. Varieties Burgundskiy, Buriy, VIR-1, Nakutvneuli, Pochatochnyy, Tavrosi, Tashkentskiy had no symptoms of white rot damage both in 2019 and 2020.