Thermal Requirements, Phenology, and Maturation of Juice Grape Cultivars Subjected to Different Pruning Types

Abstract

The purpose of this study was to assess the impacts of pruning methods (short and mixed pruning) on the duration of phenological phases and thermal requirements of juice grape cultivars (‘Bordô’, ‘BRS Cora’, and ‘BRS Violeta’), as well as to confirm the development of chemistry throughout berry ripening. The duration of the following phenological phases was measured in days after pruning over two production cycles: budburst, full-bloom, setting, veraison, and ripening. Degree days were used to compute the thermal requirements. Soluble solids, pH, titratable acidity, and maturation index were all measured as the berries ripened. There was no impact on the length of the phenological cycle or the thermal necessities of the vines due to the various types of pruning. In terms of cultivars, ‘BRS Violeta’ was found to be earlier than ‘Bordô’ and ‘BRS Cora’. In terms of chemical evolution, the berries achieved 16 °Brix at 21 and 28 days following the veraison, and the greatest values obtained were 17.0 (‘BRS Violeta’) and 18.4 °Brix (‘BRS Cora’). Furthermore, ‘BRS Cora’ produced more acidic berries. However, regardless of cultivar, the grapes were of high quality, making them a viable option for Brazilian subtropical viticulture.

Keywords

• subtropical viticulture
• BRS Violeta
• BRS Cora
• Bordô
• mixed pruning
• short pruning