Spatial Distribution of Grapes Sugar Content and its Correlations with Climate Characteristics and Climate Suitability in the Huși (Romania) Wine Growing Region

Abstract

Previous studies have analyzed mainly the spatial distribution of grapes quality parameters at the plot scale, and concluded that grapes sugar content is a variable parameter, with a less predictable spatio-temporal evolution. Our study aimed to identify a pattern of spatial variation of grapes sugar content at a regional scale, under the temperate continental climate of the Huşi (Romania) wine growing region. In order to do this, grapes sugar content was analyzed in relation to climate. The conditioning of grapes sugar content by climatic factors was analyzed based on regression models (Pearson correlation coefficient, coefficient of determination, linear regression). Spatial variation of grapes sugars content was achieved by the regression - kriging approach, using climate suitability as predictor. Spatial variation of obtainable wine types was achieved by classifying the spatial distribution of grapes sugar content, according to DOC wine production regulation for the Huși area. The study revealed that among climatic factors, the actual sunshine duration is the most influential one on grapes sugar content. Mapping grapes sugar content generated a coherent spatial distribution pattern at the vineyard scale, as it significantly correlates with terrain altitude. Based on grapes sugar content spatial variation, two areas with different potential for sugars accumulation into grapes were delineated. The outcomes reveal that grapes sugar content presents significant correlations with climate variables specific to vineyards and with climate suitability for wine production. Knowing these correlations allows revealing patterns that determine the spatial distribution of the grapes sugar content.