Grapevine vigour is correlated with N-mineralization potential of soil from selected cool climate vineyards in Victoria, Australia

INTRODUCTION: Foam stability of sparkling wines is significantly favored by the presence of surface active agents such as proteins and polysaccharides [1]. For that reason, the renowned sparkling wines are aged after the second fermentation in contact with the lees for several months (even years). Thereby wines are enriched in these macromolecules due to yeast autolysis. Since this practice is slow and costly, winemakers are seeking for alternative procedures to increase their concentration in base wines. In that sense, the supplementation with inactive yeast during alcoholic fermentation has been proposed [2]. The aim of this study was to determine whether this new strategy is really useful for enriching base wines in macromolecules and for improving foam properties of the base wines.

La D.O. Ribeira Sacra (Galicia, N.O. de España) se distribuye a lo largo de las riberas de los ríos Miño y Sil. Su característica mas destacada son las fuertes pendientes. Desde 1990 se estudia el estado

In order for a spatialized gestion of wine-producing areas, delineation of viticultural zones is needed. Viticultural zoning according to qualitative expression of varieties is a great concern

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,

Nitrogen (N) uptake by grapevine roots in forms like nitrate, ammonium, urea, or amino acids influences vegetative and generative growth, impacting grape quality and wine sensory profile. The study examined nitrogen’s influence on phenolic compounds in leaves, berries, and wine across different scales — hydroponics, soil culture, and vineyard trials. Nitrogen forms altered metabolite patterns in leaves and wine significantly, affecting aroma and flavor. Key nitrogen assimilation enzymes (NR, NiR, GS) in grapevine rootstocks responded to nitrogen forms and timing. Hydroponically grown rootstocks fertilized with various forms showed differences in enzyme expression and activity, suggesting rootstocks can assimilate amino acid glutamine (Gln).