Grape development revisited through the single-berry metabolomic clock paradigm

Aroma and mouthfeel cues are the main characteristics defining red wine quality. During wine tasting, perceptual and physical-chemical phenomena leading to mutual interactions between volatiles and non-volatiles sensory active compounds, can occur. Aroma perception depends on the release of volatiles from wine, that is affected by wine constituents present in the medium (Pittari et al. 2021; Lyu et al. 2021). Our aim was to evaluate the effect of the non-volatile wine matrix composition (polyphenols, PPh) on the release and perception of red wine aromas by an experiment of matrix enrichment.

Un vasto programma si riferisce alla verifica di 28 selezioni clonali di Pinot nero atte a vini base spumante. Gli impianti sono stati realizzati in diversi ambienti delle Langhe e del Monferrato nel periodo 1992-1996, in 57 vigneti diversi e su una superficie complessiva di circa 50 Ha.

During alcoholic fermentation, nitrogen is one of essential nutrient for yeast as it plays a key role in sugar transport and biosynthesis of and wine aromatic compounds (thiols, esters, higher alcohols). The main issue of a lack in yeast assimilable nitrogen (YAN) in winemaking is sluggish or stuck fermentations promoting the growth of alteration species and leads to economic losses. Currently, grape musts are often characterized by low YAN concentration and an increase of sugars concentration due to global warming, making alcoholic fermentations even more difficult. YAN depletion can be corrected by addition of inorganic (ammonia) or organic (yeast derivatives products) nitrogen during alcoholic fermentation.

Monitoring vine water status is a major challenge for vineyard management because it influences both yield and harvest quality. It is also a challenge at the territorial scale for identifying periods of high water restriction or zones regularly impacted by water stress. This information is of major importance for defining collective strategies, anticipating harvest logistic or applying for irrigation authorisation. At this spatial scale, existing tools and methods for monitoring vine water status are few and often require strong assumptions (e.g. water balance model). This paper proposes to consider a collaborative collection of observations by winegrowers and wine industry stakeholders (crowdsourcing) as an interesting alternative. Indeed, it allows the collection of a large number of field observations while pooling the collection effort. However, the feasibility of such a project and its interest in monitoring vine water status at regional scale has never been tested.

The objective of this article is to explore the possibility of making a regional map of vine water status based on crowdsourcing observations. It is based on the study of the free mobile application ApeX-Vigne, which allows the collection of observations about vine shoot growth. This information is easy to collect and can be considered, under certain conditions, as a proxy for vine water status. This article presents the first results obtained from the nearly 18,000 observations collected by winegrowers and wine industry stakeholders during 2019, 2020 and 2021 seasons. It presents the vine shoot growth maps obtained at regional scale and their evolution over the three vintages studied. It also proposes an analysis of the factors that favoured the number of observations collected and those that favoured their quality. These results open up new perspectives for monitoring vine water status at a regional scale but above they provide references for other crowdsourcing projects in viticulture.

Context and purpose of the study. The vine is generally a very fertile plant when compared to other tree species.