The warmer and drier climate will challenge Portuguese viticulture negatively impacting the economy, particularly for renowned winemaking regions such as the Douro Demarcated Region. In the context of climate change, the production of grapes and the sustainability of the vineyard are vulnerable to the effects of high radiation, heat and drought during the summer period. These conditions affect negatively the vines at the phenological, physiological and biochemical levels. The shortage of water resources makes irrigation practically unsustainable from an economic and environmental point of view, being crucial to implement alternative and eco-friendly measures for a better balance between vines and the environment, helping to mitigate the effects of climate change. In this work, we applied a suspension of silicon (2.5 %) in a commercial vineyard located in the Douro Superior sub-region (Santa Comba da Vilariça) to understand its effects on increasing tolerance to water stress in Touriga-Franca cv. grapevines. The experiments were divided into three treatments: i) positive control - with a deficit irrigation (25% of ETc), ii) negative control - without irrigation and iii) silicon - SiO2, applied in pré veraison. After the statistical analysis, the results showed that at veraison silicon treated plants presented fruits with higher significant values of total phenols, pH and brix°, when compared with both irrigated and non-irrigated ones. At maturation, the silicon treated plants showed fruits with higher anthocyanins, alcohol, pH and brix° content than the negative control. Accordingly, we can suggest that silicon foliar treatment could be an alternative to deficit irrigation strategies to mitigate water stress without negative impact on berry quality. This work was supported by National Funds by FCT - Portuguese Foundation for Science and Technology, under the project UIDB/04033/2020, and by the project I&D&I AgriFood XXI (NORTE-01-0145-FEDER-000041), cofunded by the European Regional Development Fund (FEDER) through NORTE 2020 programme (2014/2020). We also want to thank the TECNIFERTI enterprise for their support to provide us the silicon. info:eu-repo/semantics/publishedVersion
