Cover crop influence on water relations, yield, grape and wine composition of Pinot noir

Assyrtiko is a rare ancient grape variety that constitutes one of the most popular in Greece. The objective of the current research was to evaluate indigenous Saccharomyces cerevisiae isolates as fermentation starters and also test the possible strain impact on volatile profile of Assyrtiko wine. 163 S. cerevisiae isolates, which were previously selected from spontaneous alcoholic fermentation, were identified at strain level by interdelta-PCR genomic fingerprinting. Yeasts strains were examined for their fermentative capacity in laboratory scale fermentation on pasteurized Assyrtiko grape must.

Quercetin-3-glucoside, a grape flavonol defence metabolite, is extracted during winemaking and may undergo subsequent degradation in wines. Hydrolysation reactions lead to the formation of the aglycone quercetin, which presents limited solubility in the wine matrix and can induce visible precipitations.

Global warming is one of the biggest environmental, social, and economic threats. In the Douro Valley, change to the climate are expected in the coming years, namely an increase in average temperature and a decrease in annual precipitation. Since vine cultivation is extremely vulnerable and influenced by the climate, these changes are likely to have negative effects on the production and quality of wine.
Adaptation is a major challenge facing the viticulture sector where the choice of plant material plays an important role, particularly the rootstock as it is a driver for adaptation with a wide range of effects, the most important being phylloxera, nematode and salt, tolerance to drought and a complex set of interactions in the grafted plant.
In an experimental vineyard, established in the Douro Region in 1997, with four randomized blocs, with five varieties, Touriga Nacional, Tinta Barroca, Touriga Franca and Tinta Roriz, grafted in four rootstocks, Rupestris du Lot, R110, 196-17C, R99 and 1103P, data was collected consecutively over 20 years (2001-2020). Phenological observations were made two to three times a week, following established criteria, to determine the average dates of budbreak, flowering and veraison. During maturation, weekly berry samples were taken to study the dynamics of sugar accumulation, amongst other parameters. Climate data was collected from a weather station located near the vineyard parcel, with data classified through several climatic indices.
The results achieved show a very low coefficient of variations in the average date of the phenophases and an important contribution from the rootstock in the dynamic of the phenology, allowing a delay in the cycle of up to10-12 days for the different combinations. The Principal Component Analysis performed, evaluating trends in the physical-chemical parameters, highlighted the effect of the climate and rootstock on fruit quality by grape varieties.

Oloroso Sherry is a typical fortified wine from Jerez de la Frontera (south of Spain). It is one of the most used in the seasoning of oak barrels, called Sherry Cask, destined in this area for ageing brandies or condiments as wine vinegars. Brandy de Jerez is an European Geographical Indication for grape-derived spirits. Its special organoleptic characteristics are due to its traditional dynamic ageing in Sherry Casks. American oak is the most common wood employed in Jerez area, where Brandy de Jerez is exclusively manufactured. During ageing period of Sherry and brandies, the wood is not only a container, it is involved in several physicochemical process with the Sherry or the distillate. Oak wood is the responsible of the presence of many compounds in the products, affecting their aroma and chemical composition and having a high influence in their final quality. Moreover, the seasoned wood with Sherry wine could transfer the compounds from wine into the brandy, improving its aroma and flavor.

The current levels of greenhouse gas emissions are expecting to provoke a change on the environmental conditions which, among others, will include a rise of global mean surface temperature and an increment of atmospheric CO2 levels (IPCC, 2014), known as climate change. The response of grapevine (Vitis vinifera L.), one of the most important crops in Europe, from both a cultural and economic point of view, is not completely understood yet and the studies considering the interaction between factors are scarce. Besides, the potential variety of responses among somatic variants needs to be studied in order to be exploited in the avoidance of undesired traits linked to climate change (Carbonell‐Bejerano et al., 2015).