The Effect of Different Rootstocks and Berry Heterogeneity on Phytochemical Properties in Vitis vinifera Papazkarası Grape Variety

There are differences in development and composition between the clusters on the vines and the grape berries on the clusters. Therefore, grouping berries by size in wine grape varieties can help better manage the composition of the wine to be produced. The aim of this research is to reveal the effect of berry heterogeneity on primary and secondary metabolites in the cv. Papazkarası. The Papazkarası vines are grafted onto the rootstocks 1103P, 110R, and 420A and are trained in the double Cordon Royat system. The clusters harvested from each rootstock were separated into individual berries. These berries were then grouped by size using sieves. The size groups were: ≤12.00mm; 12.01-14.00mm; 14.01-16.00mm; 16.01-18.00mm; and ≥18.00mm, forming five groups. A control group was created by taking berries from each size group. In terms of primary metabolites in the must, the Papazkarası/1103P combination and the ≥18.00 mm size group stood out. However, the maturity indices, °Brix, and % alcohol criteria were found to be insufficient for all rootstocks and berry sizes. Regarding secondary metabolites, it was found that the ≤12.00mm and 12.01-14.00mm size groups had high values in all graft combinations. The size group with the highest total anthocyanin and total phenolic content was the ≤12.00mm group. Based on these results, berry size reduction practices will improve quality. The quality of the wines obtained from different size groups should also be supported by sensory analyses. Sorting the berries by size will positively impact grape and thus wine quality.