Aspectos fisiológicos de videiras sob o manejo da duplapoda no Sul de Minas Gerais

Abstract

The cultivation of fine grapes for the production of wine in subtropical and tropical regions has been increasing in Brazil. The biggest management obstacle is related to the high temperatures and the excessive rainfall at harvesting, negatively impacting the wine quality. The cultivation in Southern Minas Gerais State has proven to be possible and allowed the production of fine wines by managing the harvest with a double-pruning procedure, shifting the harvest to late fall when the rainfall decreases and the temperature amplitude increases. Thus, the study aimed at evaluating the physiological and phenological behavior of three varieties of Vitis vinifera, Syrah, Cabernet Sauvignon, and Sauvignon Blanc under double-pruning management grown in the municipality of Três Pontas, Southern Minas Gerais State. The plants have been evaluated with respect to the Phenology, Growth, Leaf Area, Gas Exchange, NDVI, Chlorophyll, and Total Soluble Sugar throughout the production cycle. It was observed that the variety Sauvignon Blanc completed its cycle in 159 days, while the other ones required approximately 200 days to complete their cycle. The variety Syrah had thicker trunk and longer arms as well as larger leaf area throughout the production cycle, indicating greater accumulation of reserves. The three varieties evaluated have shown proper water status in all phenologic stages referring to the values of maximum (approximately -0.20 MPa) and minimum (approximately -1.5 MPa) water potential. The Syrah grape had the highest Photosynthesis and Transpiration values. The varieties exhibited an increased NDVI value at the bunch closure stage and decreased at the maturation stage, even with no reduction of the chlorophyll quantification. The Sauvignon Blanc grape showed a significant increase in Total Soluble Sugar which explains the premature harvesting. We concluded that the varieties have distinct behavior, yet they are well-adapted to the double-pruning management.