Berries variability: Causes and effects on the quality of ‘Cabernet Sauvignon’

Abstract

In this study the objective was to investigate if differences in berry size (within a population of berries from different bunches) and flowering process would lead to differences in qualitative parameters and berries variability. The trial was conducted during the 2009 vegetative season at an irrigated ‘Cabernet Sauvignon’/1103 P vineyard. At the beginning of flowering, for 100 inflorescences, all open flowers were marked by red ink while 5 days later, closed flowers were marked by black ink. Open and closed flower distribution was investigated along the rachis. At pea size, 20 marked bunches were sampled. The diameter and weight of all berries was measured and Gaussian distribution was performed. The smallest (≤7 mm) and the largest (≥9 mm) berries, representing the lateral of the Gaussian distribution of the berry population, were taken into account. Large berries belonged to “red flowers” while small berries belonged to “black flowers”. Development of the two berry categories was evaluated from pea size (June 12) to harvest (September 16) in terms of berry mass, equatorial berry diameter, soluble solid, pH, titratable acidity, total anthocyanin and flavonoids content (mg kg-1 of grapes, mg berry-1). Significant differences were recorded between the two berry categories in terms of morphological and qualitative parameters. Results confirmed that differences in berry size can exist within a cluster and berries from the same bunch do not have similar metabolic process behavior. The sink strength relationships are mainly influenced by progressive flowering on the same bunch, modifying berry parameters.