ASSESSMENT OF THE EFFECT OF CLIMATIC FACTORS ON THE INDICATORS OF RED GRAPE VARIETIES

Heat and moisture supply are key climatic parameters to determine the possibility and efficiency of growing crops including grapes. Climate change causes a significant uncertainty not only in potential adaptive capabilities of grape plants, but also in the prospects of viticulture development in general. This problem assumes a greater importance in the context of global climate change, since this process can lead to a shift in the areas of high-quality viticulture and winemaking. Studying the patterns of influence of climatic factors on the productivity of vineyards and quality characteristics of raw materials, as well as final products will allow optimizing the efficiency of using natural resources, and reducing the negative impact of climate change on agricultural production. The goal of the work is to study the effect of climatic factors on biochemical and physicochemical indicators of red grape varieties. Materials and methods. The objects of the study were red grape varieties ‘Bastardo Magarachskiy’ and ‘Cabernet Sauvignon’, growing in different viticulture and winemaking region of Crimea. As climatic indices characterizing the heat and moisture supply of the territory, we used the total amount of precipitation from the beginning of growing season until harvest, the total amount of precipitation for the last month before harvest, hydrothermal coefficient of Selyaninov, as well as the sum of active temperatures above 10 °C (∑ Т°С10), Huglin heliothermal index (HI), Winkler index (WI), average air temperature from the growing season beginning until harvest (tgr), average air temperature for the last month before harvest (tmonth), cool night index (CI). To assess the carbohydrate-acid complex of grapes, the following indicators were used: mass concentration of sugars, titratable acids and malic acid. Results and conclusion. Distribution of climatic factors characterizing different viticulture and winemaking regions of Crimea, as well as their effect on the quality characteristics of raw materials were assessed. It was established that the Mountain Valley Coastal and Mountain Valley viticulture and winemaking regions were characterized by higher values of Winkler and Huglin indices (by 354-435 and 97-124 units, respectively), than the Crimean Western Coastal Piedmont region and the city of Sevastopol. A similar tendency was observed for the indicators tmonth, tgr and CI. A linear dependence of the mass concentration of sugars in a berry on the level of heat supply in the region during growing season was established (rwi = 0.73). A correlation was estimated between Pgr and the mass concentration of malic acid in a berry (r = 0.88-0.9). Based on the meteorological data, the patterns established will allow oenologists to estimate quality indicators of further harvest, and plan in advance technological aspects of grape processing in order to obtain high-quality wine products.