Organic Acids and Sugars in Musts of Irrigated Grapevines in Northeast Portugal

Abstract

In northeast Portugal traditionally the vineyards are non-irrigated and produce musts with high sugar content and very low acidity, quite below the preferred 6 to 7 mg l−1 equivalent of tartaric acid, thus, it is a common commercial practice to correct the wine acidity adding tartaric acid. As the practice of irrigation is now more widespread, we have set up an experimental field to evaluate the potential of altering soil water content at different timings and rates on producing musts with higher content of organic acids and to determine the best irrigation strategy to achieve that purpose with the least impact on the sugar content. Moderate amounts of irrigation from flowering to veraison improve productivity and limited the negative impacts on must quality.