Vine phenology and climate in Bordeaux, since the beginning of the XIXth century

The ongoing challenge of climate change is driving the need for novel oenological approaches aimed at finding effective environmental solutions.

The amount of synthetic pesticides applied in viticulture is relatively high compared to other agricultural crops, due to the high sensitivity of grapevine to diseases such as downy mildew (Plasmopora viticola). Alternatives to reduce fungicides are utterly needed to promote a sustainable vineyard-ecosystems and meet consumer acceptance. Essential oils (EOs) are amongst the most promising natural plant protection agents and have shown their antifungal properties previously. However, the efficiency of EOs depends highly on timing and application technique.

Dans une région comme la Toscane, zone dans laquelle sont produits certains des meilleurs vins italiens et du monde, la province d’Arezzo a actuellement une importance relativement marginale

In Valtellina zone (north Italy), the winemaking of ‘Nebbiolo’ grapes leads to the production of two main wine types: classic red wines from fresh grapes, usually classified as Valtellina Superiore DOCG (mandatory oak aging) or Rosso di Valtellina DOC, and the Sforzato di Valtellina DOCG, which is produced using withered grapes according to traditional product specification and subjected to mandatory oak aging process. The withering process influences grape chemical composition and, in turn, the wine sensory profile, which is strongly linked to the wine quality and typicity perceived by consumers.

Barolo DOCG is an economically important wine producing region in Northwest Italy. It is a small region of approximately 70 km2 gross area. The topography is very complex with steep sloped hills ranging in elevation from below 200 m to 550 m. Barolo DOCG wine is made exclusively from the Nebbiolo grape. Bioclimatic indexes are often used in viticulture to gain a better understanding of broader climate trends which can be compared temporally and geographically. These indexes are also used for identifying potential phenological timing, growing region suitability, and potential risks associated with expected climatic changes. Understanding how topography influences bioclimatic indexes can help with understanding of mesoscale climate behaviour leading to improved decision making and risk management strategies. The average monthly maximum and minimum temperatures, the Cool Night Index, the Huglin Index, and the monthly diurnal range (from July to October) were calculated using data from 45 weather stations within a 40 km radius of the Barolo DOCG growing area between the years 1996 and 2019. Linear and multiple regression models were developed using independent variables (elevation, aspect, slope) extracted from a digital elevation model to identify significant relationships. Bioclimatic indexes were then kriged with external drift using independent variables that showed significant relationships with the bioclimatic index using a 100 m resolution grid. The maximum monthly temperatures and the Huglin Index showed consistent significant negative relationships with elevation in all years. The minimum monthly temperatures showed no relationship with elevation but in some months a small but significant relationship was observed with aspect. Due to the lack of a relationship between minimum monthly temperatures and elevation compared to the significant relationship between maximum monthly temperatures and elevation, monthly diurnal range had a negative relationship with elevation.