terclim by ICS banner
IVES 9 IVES Conference Series 9 International Congress on Grapevine and Wine Sciences 9 2ICGWS-2023 9 Impact of temperature and solar radiation on grape composition variability in the Saint-Emilion winegrowing area 

Impact of temperature and solar radiation on grape composition variability in the Saint-Emilion winegrowing area 

Abstract

Grape composition is strongly influenced by climate conditions. Their expected modifications in near future, notably because of increased temperatures, could significantly modify the biochemical composition of berries at harvest, and thus wine typicity and quality. Elevated temperatures favor sugar accumulation in grapes, enhance malic acid degradation and modify the amino acid content. They also reduce significantly anthocyanin accumulation in Merlot,leading to the imbalance between anthocyanins and sugars, while no significant effects on final anthocyanin levels were reported in Tempranillo[1] and finally affect aromas or aroma precursors. However, at local scale, several other environmental factors also contribute to the overall berry composition variability between nearby vineyards and the impact of each individual factor is difficult to identify. In this context, the objective of our study was to clarify the effect of temperature variability across a network of vineyards from the Saint-Emilion and Pomerol wine producing areas, by selecting well-characterized Merlot plots presenting significant temperature differences and gradients at various time scales linked to environmental factors[2].

The selected sites were characterized by similar soils, vine age and training system. The average temperature difference during the ripening period was about 2°C between the coldest and warmest sites. Samples of 20 to 50 berries were collected at different phenological stages from véraison to maturity in 2019 and 2020. In order to further investigate the putative impact of cluster exposure to solar radiation, the biochemical composition of berries in clusters from each side of differently oriented rows (E/W or N/S) was evaluated separately and combined with RNA-seq technology to screen differentially expressed genes at the transcriptome level.

Results showed significant effects on grape composition and gene expression profiles in relation with temperature, site, and bunch azimuth, with a noteworthy impact of temperature and solar radiation exposure on anthocyanin content in grape skins.

Acknowledgements: this project was supported by “Conseil Interprofessionnel des Vins de Bordeaux “ (CIVB) n°51640/18008/9/10

References :

  1. Arrizabalaga-Arriazu, M. et al, (2020). High temperature and elevated CO2 modify berry composition of different clones of grapevine (Vitis vinifera L.) cv. Tempranillo, Front. Plant Sci. dec 2020, 11:603687. doi: 10.3389/fpls.2020.603687
  2. de Rességuier L et al (2020). Temperature variability at local scale in the Bordeaux area. Relations with environmental factors and impact on vine phenology. Front Plant Sci. may 20,11:515. doi: 10.3389/fpls.2020.00515

DOI:

Publication date: October 11, 2023

Issue: ICGWS 2023

Type: Poster

Authors

Ghislaine Hilbert-Masson1, Christel Renaud1, Philippe Pieri1, Laure de Rességuier1, Cécile Thibon2, Céline Cholet2, David Lecourieux1, Sabine Guillaumie1, Nathalie Ollat1

1 EGFV, Univ. Bordeaux, Bordeaux Sciences Agro, INRAE, ISVV, 33882 Villenave d’Ornon, France
2 Univ. Bordeaux, Bordeaux INP, INRAE, OENO, UMR 1366, ISVV, 33140 Villenave d’Ornon, France / Bordeaux Sciences Agro, 33170 Gradignan, France

Contact the author*

Keywords

vineyard, Merlot, climate change, solar radiation, metabolites, anthocyanins

Tags

2ICGWS | ICGWS | ICGWS 2023 | IVES Conference Series

Citation

Related articles…

Identification of several glycosidic aroma precursors in six varieties of winemaking grapes and assessment of their aroma potential by acid hydrolysis

In winemaking grapes, it is known that most aroma compounds are present as non-volatile precursors, such as glycosidic precursors. In fact, there is strong evidence supporting the connection between the content of aroma precursors and the aromatic quality of wine [1]. Acid hydrolysis is preferred to reveal the aroma potential of winemaking grapes, as it predicts more accurately the chemical rearrangements occurring during fermentation in acidic environments [2]. In this study, a method involving a fast fermentation followed by acid hydrolysis at 75ºC was used to evaluate the accumulation of aroma compounds over time in fractions obtained from six different varieties of winemaking grapes.

Foliar application of urea improved the nitrogen composition of Chenin grapes

The nitrogen composition of the grapes directly affects the developments of alcoholic fermentation and influences the final aromatic composition of the wines. The aim of this study was to determine the effect and efficiency of foliar applications of urea on the nitrogen composition of grapes. This study was carried out during 2023 vintage and in the Chenin vineyard located in Estacion Experimental Mendoza (Argentina). Three urea concentrations 3, 6 and 9 Kg N/ha (C1, C2, and C3, respectively) and control (T) were applied in this vineyard at veraison. In all solutions were added 1ml/l of Tween 80 ® surfactant.

Effect of spray with autochthonous Trichoderma strains and its secondary metabolites on the quality of Tempranillo grape

Trichoderma is one of the most widely used fungal biocontrol agents on vineyards due to its multiple benefits on this crop, such as its fungicidal and growth promoting capacity. In this work, we have analyzed the effect on the concentration of nutrients in grapevine leaves and on the quality of the grape must after spraying an autochthonous strain of Trichoderma harzianum and one of the main secondary metabolites produced by this genus, 6-pentyl-α-pyrone (6PP).

Influence of different Lachancea thermotolerans strains in wine acidity

Wine acidity is a parameter of great importance that influences different quality factors of the product such as biological stability or organoleptic characteristics. In the current context of climate change, which gives rise to wines with higher levels of ethanol and lower acidity, the biological acidification with yeast species such as Lachancea thermotolerans could be a solution.
In this work, the effect of the inoculation of different L. thermotolerans on the acidity of wine was studied.

The use of δ13C as an indicator of water use efficiency for the selection of drought tolerant grapevine varieties

In the context of climate change with increasing evaporative demand, understanding the water use behavior of different grapevine cultivars is of critical importance. Carbon isotope discrimination (δ13C) measurements in wine provide a precise and integrated assessment of the water status of the vines during the sugar accumulation period in grape berries. When collected over multiple vintages on different cultivars, δ13C measurements can also provide insights into the effects of genotype on water use efficiency.