Phenology and maturation of Cabernet Sauvignon grapes from young vineyards at Santa Catarina state, Brazil – a survey of vineyard altitude and mesoclimat influences

Cabernet Sauvignon grapes from recently planted vines in Santa Catarina State (Brazil), were sampled during ripening from the 2005 and 2006 vintages. The grapes were from five vineyards at different altitudes (774, 960, 1160, 1350 and 1415 m above sea level). Samples were analyzed for total soluble solids (TSS), titratable acidity (TA), Maturation Indices (TSS/TA and TSS x pH²), pH, total anthocyanins, total polyphenol index (TPI) and berry weight at 10-day intervals from véraison to harvest. Glories parameters were evaluated at maturity. Regression analysis and principal components analysis (PCA) were used to relate harvest data (berry composition at maturity and phenological events: budbreak, floraison and véraison) as a function of mesoclimate and vineyard altitude.
For the vintages studied, titratable acidities ranged from 0.59 to 0.955 g/100 mL of tartaric acid and pH from 3.42 to 3.85. In every instance titratable acidities were lower in 2005 than in 2006. At the commencement of ripening the titratable acidity was always much greater at the two highest vineyards. TSS values at harvest were 21.35-23 and 20.77-24.17 for the 2005 and 2006 vintages, respectively. At maturity, total anthocyanins ranged from 310 to 401 in 2005 and from 304 to 477 (mg of malvidin-3-glicoside) in 2006 vintage. TPI levels (mgGAE/100 g of grapes skins) ranged from 652 to 906 in 2005 and from 739 to 966 in 2006 vintage. PCA clearly separated the different sites in relation to berry composition at maturity. Climate was strongly correlated with indices of phenological precocity and with vineyard altitude. A positive relationship was observed between the altitude – air temperature climate parameters and the duration of the grapevine phenological cycle (IPCY). Thus the vineyard at 774 m had the shortest IPCY while the vineyard at 1415 m had the longest IPCY. Other important relationships were observed during maturation of berry grapes: increases in pH and polyphenols and anthocyanins and a decrease in total acidity. Winkler Scale classifications (degree-days from budbreak to harvest) for the five vineyards have approximate values of 1380 to 2000. Thus the vineyards at 1415, 1350 m are in Regions I and II respectively, while the vineyards at 960 and 1160 m are in Region III and the vineyard at 774 m is in Region IV. Rainfall registered at meteorological stations from budbreak to harvest (2005 and 2006 vintages) ranged from approximately 450 to 980 mm. In general, it was concluded that Santa Catarina State is suitable for Cabernet Sauvignon growing.