Understanding the impact of rising temperatures due to climate change on aromatic compositions in Malbec wines from Mendoza, Argentina

The effects of climate change in viticulture are currently a major concern, with heat waves and drought affecting yield, wine quality, and in extreme cases, even plant survival. Ancient grapevine varieties have high intravarietal genetic variability that so far has been explored successfully to improve yield and must quality. Currently, there is little information available on intravarietal variability regarding responses to stress. In the current work, the intravarietal genetic variability of several Portuguese varieties was studied for yield, must quality, and tolerance to abiotic stress, through indirect, rapid, and nondestructive measurements carried out in the field.

Every year, viticulture is facing several outbreaks caused by established diseases, such as downy mildew and grey mould, which possess different life cycles and modes of infection. To cope with these different aggressors, grapevine must recognize them and arm itself with an arsenal of defense strategies.
The regulation of secondary metabolites is one of the first reactions of plants upon pathogen challenge. Their rapid biosynthesis can highly contribute to strengthen the defense mechanisms allowing the plant to adapt, defend and survive.

Light is a fundamental part at sales points which influences in the conservation of wines, particularly in those that are sold in transparent glass bottles such as rosé wines and increasingly white wines. The photochemical effect known as “light-struck taste” can cause changes in the aromatic characteristics of the wine. This “light-struck taste” is due to reactions triggered by the photochemical sensitivity of riboflavin (RBF).

The interest in sustainable and ecologic agricultural practices in grapevine has grown significantly in recent years in the context of ecological transition. Organic mulches are treatments that support the circular economy and positively affect the soil and the plant. They are an alternative to herbicides and other conventional practices since they may influence soil moisture, erosion, structure and weed control. However, their effects on the soil and must microbiota remain unknown.

The global warming phenomenon involves the frequency of extreme meteorological events accompanied by a change in rainfall distribution. Irrigation frequency (IF) affects the spatial and temporal soil water distribution but its effects on the phenolic composition of the grape have been scarcely studied. The aim of this work was to evaluate the effects of four deficit irrigation frequencies of 30 % ETo: one irrigation per day (T01), two irrigations per week (T03), one irrigation per week (T07) and one irrigation every two weeks (T15) on berry phenolic composition at harvest.