TY JOUR TI SEASONAL DYNAMICS OF SUGAR CONTENT AND ACIDITY IN BERRIES OF THE DON NATIVE GRAPE VARIETY VARYUSHKIN KW grapes KW ampelographic collection KW native Don variety KW sugar content of berry juice KW titratable acidity KW correlation analysis KW regression analysis KW agrometeorological dependence KW seasonal dynamics JO Bulletin of KSAU AU Novikova, L.Y. AU Naumova, L.G. AU Ganich, V.A. PY 2023 IS 0 PB Krasnoyarsk State Agrarian University