Maturation curves of 'Tannat' grape (Vitis vinifera L.) for red winemaking

Abstract

The objetive of this research was to characterize the maturation of 'Tannat' grape (Vitis vinifera L.) produced in the northwest of Parana state, for red winemaking. The experimental area was established in a commercial vineyard of Vinícola Intervin®, Maringá, PR. The vineyard was planted in August of 2000 and the vines were trained in a pergola system, in a 4.0 x 1.0 m spacing, budded on 'IAC 766 Campinas' rootstock. The evaluations started from the winter pruning of 2003. The random design was used as the statistical model with 20 replications and each plot was composed by one tree. The maturation curves of 'Tannat' grape were determined through chemical characteristic analysis of berries, such as total soluble solids (TSS), titratable acidity (TA) and maturation index (TSS/TA), which were evaluated weekly from early ripening to 7 days after harvest, processing 300 berries per sampling. Through regression analysis, the performance of these chemical characteristics was evaluated over time. It was possible to conclude that: the curves of TSS, TA and TSS/TA were well-fitted to the cubic model and; the 'Tannat' grape reached 21.20 oBrix, 1.04% of tartaric acid and 20.38 of maturation index during harvest, what indicates a good performance of this cultivar for red winemaking at the local condition.