Temperature variability inside a wine production area and its effect on vine phenology and grape ripening. An example from the Saint-Emilion-Pomerol

The purpose of the study was to monitor berry development as a function of site, vine water status and climate in order to improve our understanding of the role played by climate change on secondary metabolites relevant to wine quality.

During the 1985 harvest, I was able to notice in the taste perception a break in the harmony of the wine during even partial blends of grapes from different plots. At the same time, I noted a good reaction from customers for greater product customization. As a result, I was led to seek the objective limits of the terroir of a cuvée and by a constant and permanent refinement of the parameters specific to each of the terroirs.

Majority of California’s vineyards rely on supplemental irrigation to overcome abiotic stressors. In the context of climate change, increases in growing season temperatures and crop evapotranspiration pose a risk to adaptation of viticulture to climate change. Vineyard cover crops may mitigate soil erosion and preserve water resources; but there is a lack of information on how they contribute to vineyard resiliency under tillage systems. The aim of this study was to identify the optimum combination of cover crop sand tillage without adversely affecting productivity while preserving plant water status. Two experiments in two contrasting climatic regions were conducted with two cover crops, including a permanent short stature grass (P. bulbosa hybrid), barley (Hordeum spp), and resident vegetation under till vs. no-till systems in a Ruby Cabernet (V. vinifera spp.) (Fresno) and a Cabernet Sauvingon (Napa) vineyard. Results indicated that permanent grass under no-till preserved plant available water until E-L stage 17. Consequently, net carbon assimilation of the permanent grass under no-till system was enhanced compared to those with barley and resident vegetation. On the other hand, the barley under no-till system reduced grapevine net carbon assimilation during berry ripening that led to lower content of nonstructural carbohydrates in shoots at dormancy. Components of yield and berry composition including flavonoid profile at either site were not adversely affected by factors studied. Switching to a permanent cover crop under a no-till system also provided a 9% and 3% benefit in cultural practices costs in Fresno and Napa, respectively. The results of this work provides fundamental information to growers in preserving resiliency of vineyard systems in hot and warm climate regions under context of climate change.

Grapevine, Vitis vinifera, requires grafting on Phylloxera tolerant rootstocks of American origin in most viticultural areas of the world. The most commonly used species in rootstock creation are V. berlandieri, V. riparia and V. rupestris. Rootstocks not only provide tolerance to Phylloxera but assure the supply of water and mineral nutrients to the scion. The objective of this work was to determine to what extent rootstocks of different parentages alter the mineral composition of petioles of grapevine.

La caractérisation objective des terroirs viticoles est nécessaire pour mieux comprendre les relations existantes entre les sols, la plante et la qualité de la production vinicole. Dans le cadre d’une recherche sur les terroirs viticoles du canton de Vaud – Suisse, un géorépertoire pédologique et agronomique a été conçu et réalisé.