Impact of tomato black ring virus (TBRV) on quantitative and qualitative feature of Vitis vinifera L. Cv. Merlot and Cabernet franc

Downy and powdery mildew are major issues in grapevine cultivation, requiring many phytosanitary treatments to ensure yield and quality. Climatic changes are also challenging grape cultivation

The advance in maturation of wine grapes is an important climate change risk related effect that could affect warm regions like Portuguese Douro Wine Region. Indeed, the climate analysis over the past years registered a decrease in the precipitation, significant higher average temperatures, and a more frequent occurrence of extreme weather events, including heat waves. In these conditions the length from anthesis until maturation is shortened and the uncoupling of technical and phenolic maturity results in berries with higher sugar concentration (and lower acidity), but lower anthocyanins, tannins, and total phenolic concentration, which produce unbalanced wines.
In this work, an innovative strategy of crop forcing, based on forcing vine regrowth after a second pruning of green shoots, was tested, aimed at delaying ripening until the temperature becomes lower and, therefore, preventing acidity loss and increasing anthocyanin-to-sugar ratio. The experiments were conducted in 2019 and 2020 in a commercial vineyard of ‘Touriga Nacional’ located in the Douro Region. Crop forcing was conducted 15 (CF1) to 30 (CF2) days after fruit set. Vines pruned with conventional methods were used as control (CF0). Results confirmed that fruit ripening was shifted from the hot season (August/September), until a cooler period (October through early-November). At harvest, grapevine berries from CF1 and CF2 presented lower pH and higher acidity, than control, with no significant differences in colour intensity and phenolic levels composition. Sugar content was lower in CF2-treated vines in both seasons. However, in CF-treated vines the number and size of clusters were significantly lower (up to 88% reduction) than in control plants. A metabolomics analysis of mature berries from CF-treated vines and control is underway. Crop forcing was indeed effective in producing a more balance berry composition but severely reduced grapevine yield,

A large genetic diversity exists among V. vinifera varieties, but also among cultivated rootstocks. This diversity is important to adapt plant material to different environmental conditions

In this audio recording of the IVES science meeting 2022, Antonio Morata (Universidad Politécnica de Madrid, Madrid, Spain) speaks about the use of fumaric acid to control pH and inhibit malolactic fermentation in wines.

The wine sector is undergoing considerable transformation, particularly as a result of climate change and increasing consumer expectations for quality products, in a globalised and increasingly competitive market.