Abstract
The study aimed to evaluate the influence of specific viticultural and winemaking practices on the yield and physicochemical composition of wines from the Pinot Noir variety, clone 777, grown under non-irrigated conditions in the Sliven region of Bulgaria. Three variants were examined to assess how vine regulation practices affect grape and wine quality parameters. The findings demonstrated significant effects of inflorescence and bunch thinning on the accumulation of sugars, pH, and phenolic compounds. Variant V1, involving early inflorescence regulation, showed improved sugar content, balanced acidity, and higher anthocyanin concentration, resulting in wines with greater alcohol levels and extract content. Variant V2, characterized by bunch thinning during berry growth, enhanced phenolic and anthocyanin composition, contributing to more intense color and better aging potential. The control variant V0 displayed lower values across most qualitative parameters. Overall, the results confirm that moderate yield reduction through inflorescence or bunch regulation is an effective viticultural strategy to improve grape ripeness and wine quality in Pinot Noir under dry climatic conditions. These findings provide practical guidance for optimizing vineyard management to produce well-balanced, high-quality wines adapted to local terroir and climate variability.
Keywords: chemical compounds, Pinot Noir, anthocyanins, phenols