Addition of glutathione-rich inactivated yeasts to white musts: effects on wine composition and sensory quality

Plant roots fulfil important functions as they are responsible for the acquisition of water and nutrients, for anchorage and stability, for interaction with symbionts and, in some cases, for the storage of carbohydrates. These functions are associated with the Root System Architecture (RSA, i.e. the form and the spatial arrangement of the roots in the soil). The RSA results from several biological processes (elongation, ramification, mortality…) genetically determined but with high structural plasticity.

The increased intensity and frequency of heatwaves, coupled with prolonged periods of drought, are a significant threat to viticulture worldwide. During these conditions the more exposed leaves can show visible symptoms of heat damage. We monitored the functionality of photosystem II (PSII) in the field to better understand the impact of heatwaves on canopy performance. A factorial experiment was established in summer 2023 using Shiraz grapevines in the Barossa valley of South Australia, involving water-stressed and well-watered vines.

The main phenological stages (budburst, flowering, veraison, and ripeness) and the fruit composition of 34 Spanish minority varieties were studied to determine their cultivation potential and help winegrowers adapt their production systems to climate change conditions. In total, 4 control cultivars, and 30 minority varieties from central Spain were studied during a period of 3 campaigns, in the ampelographic collection “El Encín”, in Alcalá de Henares, Madrid. Agronomic and oenological characteristics such as yield, and total soluble solids concentration have been monitored.

Reducing sugar accumulation in grape (Vitis vinifera L.) berries may be a way to mitigate the effect of climate change. Managing canopy and crop load is an effective way to do so, however, reducing canopy size has been demonstrated to induce undesirable effects on anthocyanins. The aim of this study was to test if an application of exogenous ABA on the grape berries of defoliated vines (⅔ of the leaves removed) can result in slower sugar accumulation while maintaining grape and wine quality. An experiment with defoliation and exogenous ABA application on directly on clusters (factorial design 2×2) was performed with ‘Tempranillo’ fruit-bearing cuttings.

In the context of climate change with increasing evaporative demand, understanding the water use behavior of different grapevine cultivars is of critical importance. Carbon isotope discrimination (δ13C) measurements in wine provide a precise and integrated assessment of the water status of the vines during the sugar accumulation period in grape berries. When collected over multiple vintages on different cultivars, δ13C measurements can also provide insights into the effects of genotype on water use efficiency.