Application of nitrogen forms such as nitrate, urea, and amino acids effects on leaf and berry physiology and wine quality

Irrigation is an essential tool for grape production, especially where rainfall does not meet the optimal water requirements needed to achieve yield and quality targets. Increased evaporative demand of grapevines due to changing climate conditions, and a growing awareness for sustainable farming, require the improvement of irrigation techniques to maximize water use efficiency, i.e. using less water to achieve the same yields or the same water but larger yields. In this study, the performance of Cabernet Sauvignon vines was compared under three irrigation techniques: conventional aboveground drip irrigation, subsurface irrigation installed directly under the vine row, and partial rootzone drying in which two subsurface lines were buried in the middle of the two interrow spacings on each side of the vine row with irrigation alternated between the two lines based on soil moisture content.

The production of grapes with a balanced composition is one of the main goals that agronomists and oenologists pursue to produce premium quality wines.

L’aire des A.O.C. Madiran et Pacherenc du Vic-Bilh est située sur le piémont nord-occidental des Pyrénées, au nord du cône de Ger.

Tannin, anthocyanins and their reaction products play a major role in the quality of red wines. They contribute to their sensory characteristics, particularly colour and astringency. Grape tannins and anthocyanins are extracted during red wine fermentation. However, their concentration and composition change over time, due to their strong chemical reactivity1. It is also well known that yeasts influence the wine phenolic content, either through the release of metabolites involved in the formation of derived pigments1, or through polyphenol adsorption2,3.

Winegrowing regions recognized as protected designations of origin (PDOs) are closely tied to well defined geographic locations with a specific set of pedoclimatic attributes and strictly regulated by legal specifications. However, climate change is increasingly threatening these regions by changing local conditions and altering winegrowing processes. The vulnerability to these changes is largely heterogenous across different winegrowing regions because it is determined by individual characteristics of each region, including the capacity to adapt to new climatic conditions and the sensitivity to climate change, which depend not only on natural, but also socioeconomic and legal factors. Accurate vulnerability assessments therefore need to combine information about adaptive capacity and climate change sensitivity with projected exposure to new climatic conditions. However, most existing studies focus on specific impacts neglecting important interactions between the different factors that determine climate change vulnerability. Here, we present the first comprehensive vulnerability assessment of European wine PDOs that spatially combines multiple indicators of adaptive capacity and climate change sensitivity with high-resolution climate projections. We found that the climate change vulnerability of PDO areas largely depends on the complex interactions between physical and socioeconomic factors. Homogenous topographic conditions and a narrow varietal spectrum increase climate change vulnerability, while the skills and education of farmers, together with a good economic situation, decrease their vulnerability. Assessments of climate change consequences therefore need to consider multiple variables as well as their interrelations to provide a comprehensive understanding of the expected impacts of climate change on European PDOs. Our results provide the first vulnerability assessment for European winegrowing regions at high spatiotemporal resolution that includes multiple factors related to climate exposure, sensitivity, and adaptive capacity on the level of single winegrowing regions. They will therefore help to identify hot spots of climate change vulnerability among European PDOs and efficiently direct adaptation strategies.