Climatological variables and their influence on the quality of Vitis vinifera grapes in Dom Pedrito, region of Campanha, Brazil

Abstract

The climatic aspects influence the physicochemical characteristics of the grapes, interfering in the quality of the grapes, mainly in the period of cluster maturation. The objective of this study was to analyze the influence of climatic conditions and climatological variables, correlating with the physicochemical quality of viniferas Chardonnay and Tannat, from the 2019, 2020, 2021 and 2022 harvests, to evaluate a possible interference in the composition of these grapes, and consequently, in the wines to be produced, in the municipality of Dom Pedrito, Region of the Campanha. The Chardonnay and Tannat grapes were harvested at the stage of full maturation, and then physicochemical analysis were carried out to assess the quality of the must: SS (°Babo, °Brix), pH, Total acidity, Sugar and Probable alcohol. Climate data were collected 90 days before the date of harvest, for each cultivar, these being maximum, average and minimum temperatures and precipitation for each day. All DeltaT correlated positively with °Babo, °Brix and sugar for Chardonnay. As a negative correlation, P30 and minimum temperatures influenced the sugar contents. Delta6030 was negatively correlated with total acidity. For Tannat, all the variables linked to the sugar content in the grapes were positively correlated with the pH and the Tmed30. P9060 correlated positively with all sugar-related variables. Tmin9060 was negatively correlated with sugar content. Total acidity correlated positively with Tmax6030 and Tmax9060. The weather conditions when related to the cultivation of viniferas grapes directly influence the quality of the grapes.