Natural variability and vine-growers behaviour

The climate change is afecting particulary to the South of Spain, with high temperatures. It is important to develop new strategies in order to mantain the quality of wines

In Burgundy, a climat has nothing to do with the weather but accurately designates a named vine plot, often centuries-old, which produces a singular wine. This wine is the combination of history, the natural environment (relief, type of soil, exposure to the sun), a grape variety and know-how going back thousands of years. The grapes of each climat are harvested separately and the wine is made from a single grape variety and has a unique name featured on the bottle. Romanée conti, clos de vougeot, montrachet, musigny, corton…

Heatwaves or extreme heat events can be particularly harmful to agriculture. Grapevines grown in the Douro winemaking region are particularly exposed to this threat, due to the specificities of the already warm and dry climatic conditions. Furthermore, climate change simulations point to an increase in the frequency of occurrence of these extreme heat events, therefore posing a major challenge to winegrowers in the Mediterranean type climates. The current study focuses on the application of the STICS crop model to assess the potential impacts of heatwaves in grapevine yields over the Douro valley winemaking region. For this purpose, STICS was applied to grapevines using high-resolution weather, soil and terrain datasets over the Douro. To assess the impact of heatwaves, the weather dataset (1989-2005) was artificially modified, generating periods with anomalously high temperatures (+5 ºC), at certain onset dates and with specific durations (from 5 to 9 days). The model was run with this modified weather dataset and results were compared to the original unmodified runs. The results show that heatwaves can have a very strong impact on grapevine yields, strongly depending on the onset dates and duration of the heatwaves. The highest negative impacts may result in a decrease in the yield by up to -35% in some regions. Despite some uncertainties inherent to the current modelling assessment, the present study highlights the negative impacts of heatwaves on viticultural yields in the Douro region, which is critical information for stakeholders within the winemaking sector for planning suitable adaptation measures.

Vines are exposed to environmental conditions that cause abiotic stress on the plants (drought, nutrient and mineral deficits, salinity, etc.). Polyamines are growth regulators involved in various physiological processes, as in abiotic plant stress responses. Stressful conditions can modify grape’s composition, and in this work, we have focused on studying the effect of abiotic stress on the composition of polyamines and amino acids in grapes. In addition, the effect of grape variety on these compounds has been studied.

A positive role of mannoproteins on wine stability and red wine mouth sensations has been widely described. Commercial mannoproteins are available and some yeast strains are offered with a higher formation of mannoproteins.