terclim by ICS banner
IVES 9 IVES Conference Series 9 Spatial variability of temperature is linked to grape composition variability in the Saint-Emilion winegrowing area

Spatial variability of temperature is linked to grape composition variability in the Saint-Emilion winegrowing area

Abstract

Elevated temperature during the grape maturation period is a major threat for grape quality and thus wine quality. Therefore, characterizing the grape composition response to temperature at a larger scale would represent a crucial step towards adaptation to climate change. In response to changes in temperature, various physiological mechanisms regulate grape composition. Primary and secondary metabolisms are both involved in this response, with well-known effects, for example on anthocyanins, and lesser known effects, for example on aromas or aroma precursors. At the field scale or at the regional scale, however, numerous environmental or plant-specific factors intervene to make the effects of temperature difficult to distinguish from overall variability. In this study, it was attempted to overcome this difficulty by selecting well-characterized situations with differing temperatures.
A long-term study of air temperature variability across several Merlot vineyards in the Saint-Emilion and Pomerol wine producing area found significant temperature differences and gradients at various time scales linked to environmental factors. From this study area, a few sites were selected with similar age, soil and training system conditions, and with repeated and contrasted temperature differences during the maturation period. The average temperature difference during the maturation period was about 2°C between cooler and warmer sites, a difference similar to that expected under future climate change scenarios. In close vicinity to the temperature sensors at each site, grape berries were sampled at different times until full maturity during 2019 and 2020. Also, berries from bunches on either side of the row were analyzed separately, allowing an investigation of bunch exposure effect associated with the coupling of berry temperature and solar radiation. Four replicates of pooled berries for each time – site – bunch exposure combination were obtained and analyzed for biochemical composition. Analyses of variance of the biochemical composition data collected at different sampling times reveal significant effects associated with temperature, site, and bunch azimuth. For instance, anthocyanins in grape skins are clearly influenced by temperature and solar radiation exposure, with up to 30% reduction in warmer conditions.

DOI:

Publication date: May 31, 2022

Issue: Terclim 2022

Type: Article

Authors

Philippe Pieri1, Laure de Rességuier1, Nathalie Ollat1, Christel Renaud1, Cécile Thibon2, Céline Cholet2, David Lecourieux1, Sabine Guillaumie1 and Ghislaine Hilbert1

1EGFV, Univ. Bordeaux, Bordeaux Sciences Agro, INRAE, ISVV, Villenave d’Ornon, France
2UR Œnologie, Univ. Bordeaux, INRAE, ISVV, Villenave d’Ornon, France

Contact the author

Keywords

climate change, solar radiation, vineyard, network, anthocyanins

Tags

IVES Conference Series | Terclim 2022

Citation

Related articles…

Yeast diversity in Vitis labrusca l. Ecosystems

Although there are detailed studies on the microbiota of Vitis vinifera L. grapes, little is known about the diversity of yeast communities present in non-vinifera Vitis ecosystems (i.e., grapes and spontaneously fermenting grape musts). Potentially scientific and/or enological valuable yeast strains from these non-vinifera Vitis ecosystems might never be isolated from V. vinifera L. Using a standard culture-dependent strategy, we studied the population of yeast species during initial stages of spontaneous fermentation of V. labrusca L. (Isabella) grape musts. Rare non-Saccharomyces yeast species were recognized in Isabella, including Candida azymoides, Pichia cecembensis, Candida californica, Candida bentonensis, Issatchenkia hanoiensis and Candida apicola.

Tuning the pH during the fermentation has a strong effect on the wine protein composition and the stability of the resulting white wines

Previous results have shown the impact of the pH on the stability of white wine proteins. In a context of global warming that implies increases in ethanol content and pH

Apoplastic pH influences Vitis vinifera Barbera recovery responses to short and prolonged drought 

Alteration of sap pH is one of the first chemical changes that occurs within the xylem vessels of plants exposed to drought. Xylem sap acidification accompanied by the accumulation of soluble sugars has been recently documented in several species (Sharp and Davis, 2009; Secchi and Zwieniecki, 2016). Here, Vitis vinifera plants of the anysohydric cultivar Barbera were exposed to either short (no irrigation; SD) or to prolonged drought (continual reduction of 10% water; PD). When comparable severe stress was reached, the potted grapes were re-watered. SD was characterized by fast (2–3 days) stomatal closure and high abscisic acid (ABA) accumulation in xylem sap (>400 μg L−1) and in leaf. In PD plants, the rise in ABA levels was considerably diminished.

Plastic debris at vines: carriers of pollutants in the environment?

Modern agriculture employs large amounts of plastics, such as mulching and greenhouse films, thermal covers, plant protection tubes and tying tape. The latter two types are very common in viticulture. Guard tubes are employed to protect young vines from mechanic and atmospheric damage, whilst polymeric tying tape has replaced natural-origin materials to hold the canopy of vines. Both materials are made on synthetic polymers, which include a range of additives to improve their environmental stability remaining in the environment of vineyards for years. During this time, they are exposed to the range of pesticides (fungicides, insecticides and in a lesser extend herbicides) applied to vines.

Phenolic acid characterization in new varieties descended from Monastrell.

Phenolic acids are phytochemicals that are expansively distributed in daily food intake. Phenolic acids are involved in various physiological activities, such as nutrient uptake, enzyme activity, protein synthesis, photosynthesis, and cytoskeleton structure in seeds, leaves, roots, and stems. Also exhibit antibacterial, antiviral, anticarcinogenic, anti-inflammatory, and vasodilatory activities due to their antioxidant property.