Techniques for sunburn reduction in bunches in Vitis vinifera L. cv. Graciano

Viticulture is a key economic sector in the mediterranean region. However, climate change is affecting global viticulture, increasing the frequency of heatwaves and drought events.

For wine areas around the world, nature and climate are becoming factors of production whose endowment becomes a stake beyond the traditional economic factors: labor, capital, land. They strongly influence agricultural and environmental conditions for production.

Trunk diseases and esca in particular, represent a major threat to the sustainability of the vineyards. The percentages of unproductive vines in a plot could vary from 4% to over 20 % depending on local conditions and vintages.

The seasonal’s climatic conditions determine the composition of grapes at harvest as they affect the vine’s physiology and development. High temperatures during the grape ripening period cause a high accumulation of sugars and degradation of fruit acidity ,and alter the synthesis of polyphenols. Therefore, some vineyard management can be applied in order to modify grapevine impact on climate variability. One example is the pre-pruning at the beginning of grape ripening, which can delay the ripening period and modify the composition of the grapes at harvest. This work aims to evaluate the pre-pruning field technique on yield components and alcohol content in wines of Tannat and Merlot varieties.

The aim of this work is to determine the influence of viticultural and oenological factors to the aromatic potential of white wines from Colombard variety in the south west of France Gascony vineyard.