Future projections for chilling and heat forcing for European vineyards

Knowledge of the nitrogen nutrition status of grapevines is essential for the sustainable management of their nutrition for the production of quality grapes. The measurement of the chlorophyll index is a rapid, non-destructive and relatively inexpensive method that provides a good approximation of the nitrogen nutrition status of the vine during the season. Interpretation thresholds are currently insufficient or non-existent for some chlorophyll meters. Ideally, they should be available for each variety and each phenological stage. In order to popularize the use of chlorophyll-meters, measurements were carried out at Agroscope in Switzerland to establish the correlation between the indices obtained by the devices N-tester and SPAD 502.

One of the consequences of global warming is the quick berry development giving rise to a disconnection between sugar accumulation and the formation of important quality minor compounds such as phenolics and volatile compounds being a huge challenge for the oenologist [1]. Thus, this phenomenon is forcing the search on strategies for maintaining the quality of wines despite this situation. One possibility is to make an early harvest with a low sugar concentration (18ºbrix) and advanced harvest for sparkling wine (20-21ºbrix) and afterwards to combine base wines properly and carry out the second fermentation trying to compensate the lack of secondary metabolites due to the quick berry development and higher alcohol degree of the second one, not adequate itself for sparkling wine. The aim of this study was to assess the chemical and physical characteristics, mainly volatile profile, and foaming properties of sparkling wines from grapes of Chardonnay and Sauvignon blanc.

The use of glutathione (GSH) in winemaking has been legitimated recently, according to OIV resolutions OENO 445-2015 and OENO 446-2015 a maximum dose of 20 mg/L is now allowed to use in must and wine. Several studies have proven the benefits of GSH, predominantly in Sauvignon blanc. Thus, oxidative coloration of must and wine is limited, aroma compounds such as volatile thiols are preserved, and the development of ageing flavors such as sotolon and 2-aminoacetophenone is impeded. The protective effect may be explained by the high affinity of GSH to bind o-quinones which are formed during phenolic oxidation and which are known to initiate browning and other oxidative changes. Some researchers have proposed the hydroxycinnamic acid to GSH ratio (HGR) as an indicator of oxidation susceptibility of must and could show that lower ratios yielded lighter musts.

Exposure to solar radiation affects berry composition through photomorphogenesis or changes in temperature. Flavonol synthesis is upregulated by UV‐B radiation

“Vinum debet esse naturale ex genimine vitis et non corruptum”. The Eucharistic wine must be made with pure grapes that must not be contaminated in any way. This is how wine was born in the monastery of the Augustinians, and that is how the genetic improvement of grapevine implemented over the decades at the Agricultural Institute of San Michele all’Adige (since 1874; Trentino – Italy) has been oriented to make the cultivation of grapes always more sustainable. This concept is still current and meets the worldwide urgent need of reducing the use of chemicals, under a climate crisis scenario. Since the beginning of the twentieth century, the varieties introduced in Trentino and the new cultivars produced by pioneer breeders have already embraced the principle of sustainable viticulture.