Comparative agrobiological and technological characteristics of grape varieties with increased resistance to fungal diseases and low winter temperatures

With the use of statistical methods, a comparative ampelographic study was carried out of table grape varieties with increased resistance to diseases and low winter temperatures. It was established that the existing ampelographic specificity among them predetermined their grouping by proximity and distance, depending on the deviation of the parameters of their botanical, agrobiological, and technological indicators. Their grouping into two clusters according to their fertility was determined by two factors: the first principal component consisted of average yield per vine and per decare, and the second one included developed buds, fruit-bearing shoots, and fertility rate. Based on the results of the mechanical and chemical analysis of grape bunches and berries, the varieties were also divided into two clusters, with this group of indicators being distributed into four factors. The indicators with the greatest influence on their differentiation belonged to the first principal component: average bunch weight, bunch length and width, skins and mesocarp, average weight of 100 berries, and theoretical yield.