Bunchstem and berry development in Merlot and Cabernet Sauvignon and their effects on berry ripening and composition

Abstract

The project was conducted to investigate the relationship between bunchstem and berry development and consisted of four experiments on Cabernet Sauvignon and Merlot. Bunch size influenced not only berry and bunchstem size, but also some basic compositional parameters. The degree of reduction in flowers led to an increase in berry size and most often amino acids concentrations. An induced alteration of fruit set had implications on bunchstem and fruit composition, often altering berry amino acid and nutrient concentrations. Seasonal changes in xylem sap composition were also observed in a further investigation. The study underlines the interactive association between bunch berry number and the bunchstem structure and its vascular system influencing the final berry composition.

Summary

Bunch size and bunchstem structure of a particular variety can be quite variable, the bunchstem acts as a pathway for nutrient and carbohydrate flow to the berry via the vascular bundles. The development of the bunchstem and its relationship to berry composition is investigated in this study.