Poda curta e mista e sua influência nos aspectos fisiológicos e fenológicos da uva carbernet sauvignon

Abstract

Vinifera cultivars (Vitis vinifera), like Cabernet Sauvignon, possess some compounds that are responsible for stabilization and harmony of wines through the years as likely help on the combat of cardiovascular diseases, cancer and favor longevity. In this work morphometric, physico-chemical and biochemical characteristics of mature Cabernet Sauvignon grapes were analyzed, collected from plants managed in two distinct ways, short pruning (spur) and cane and spur pruning (Sylvoz), both of them with the same number of gems per plant. Experiments were conducted during 2005 and 2006. The analyses of the phenolic compounds (anthocyanins, tannins and resveratrol) were made by high performance liquid cromatography (HPLC) and spectrophotometric analysis. The physico-chemical analyses (pH, acidity and sugar) were made as determined by the Ministério da Agricultura e do Abastecimento. The results showed significant morphometrical, physco-chemical and biochemical differences among grapes collected in 2005 and 2006, as well as among grapes obtained from short and spur and cane pruning. In general, means from short pruning treatments were higher than those from mixed pruning. The concentrations of total anthocyanins and tannins were highers in 2005, a year characterized by high temperatures and sunny days, and low rainfall. However, despite the annual variations, grapes obtained from short pruning treatments exhibited higher total tannin, but not total anthocyanin content. The concentration of the anthocyanins cianydin and peonidin showed interaction year vrs. pruning. But, the concentration of malvidin and delphinidin did not varied between pruning systems, indicating that the synthesis of specific anthocyanins is differently affected by physiological conditions. Procyanidins B1, B2, B3 and B4, as well as catechin and epicatechin stayed quantitatively higher in short pruning. However, procyanidins B2 and B3 exhibited higher concentrations in 2005, and procyanidins B1 and B4 in 2006. Resveratrol concentrations were significantly higher in 2006, but it did not exhibited difference between the pruning systems. Considering all parameters evaluated in this study, the short pruning system showed advantages when compared with the spur and cane pruning conventionally used in the Rio Grande do Sul vineyards, being an alternative for the obtention of high quality wine grapes.