An evaluation of the physiological responses of young grapevines planted and maintained under water constraint 

The classification of enological tannins has gained importance following the OIV’s requirement to include their botanical origin on product labels (OIV-OENO 624-2022).

The year-on-year rise in temperatures and the increase in extreme weather events due to climate change are already having an impact on agriculture. Among the perennial fruit species, grapevine is already negatively impacted by these events through an acceleration of its phenology, more damage from late frosts or through an increase in the sugar level of the berries (and therefore the alcoholic degree of the wine) and a decrease of acidity, impacting the wine quality. Sun’Agri, in partnership with INRAE, Chambre d’agriculture du Vaucluse, Chambre d’agriculture des Pyrénées-Orientales and IFV, developed a protection system based on dynamic agrivoltaics to protect grapevine. It consists of photovoltaic solar panels positioned above the crop, high enough not to impede the passage of agricultural machinery, and tiltable from +/- 90° to adjust the level of shading on the vineyard. These smart louvers, driven by artificial intelligence (physical models & plant growth models), are steered according to the plant’s needs and provide real climate protection.

Copper is listed among the active substances candidates for substitution (Regulation EU 2015/408). Yet still, because of the lack of valid alternatives, the European Commission recently confirmed its usage authorization by limiting the maximum amount to 28 Kg per hectare in 7 years, i.e. an average of 4 kg/year (Reg. EU 2018/1981).This restriction is due to copper accumulation in soils and surface waters both caused by a steady application, especially on perennial crops (Riepert et al., 2013). The aim of this work is to determine if treatments with reduced copper dosages are able to reach different grapevine’s organs, with particular focus on the core of bunches, and if these small amounts can ensure the respect of the legislative prescription, without compromising the phytosanitary conditions of the vineyards, thus grape yields.

The chemistry of wine is notably complex and is modified by ageing of the bottles. The composition of wines is the result of vine production (under the influence of vintage, climate and soils); yeast production (under the influence of juice composition and fermentation management); lactic bacteria production (under the influence of young wine composition and malolactic fermentation management); and of the ageing process either in vats, barrels or bottles or both. The composition is linked to the quality perceived by consumers but also to their origin, sometimes associated to the “terroir” concept.

This interaction is primarily due to an acidic attack on the ceramic by the wine. It results in (1) the dissolution of the ceramic into the wine and the release of a wide variety of elements; and (2) an increase of the wine pH. The extent of these effects depends on the mineralogical and chemical composition of the ceramic, as well as the hydraulic ratio of the ceramic-wine system (the term hydraulic ratio (ρ) defines here the volume of wine over the surface area of the ceramic in contact with the wine).