GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 A pragmatic modeling approach to assessing vine water status

A pragmatic modeling approach to assessing vine water status

Abstract

Context and purpose of the study – Climate change scenarios suggest an increase in temperatures and an intensification of summer drought. Measuring seasonal plant water status is an essential step in choosing appropriate adaptations to ensure yields and quality of agricultural produce. The water status of grapevines is known to be a key factor for yield, maturity of grapes and wine quality. Several techniques exist to measure the water status of soil and plants, but stem water potential proved to be a simple and precise tool for different plant species. The interpretation however of this value remains difficult because it is influenced by both soil water content and climatic conditions at the time of measurement. Where soil water content usually follows a decreasing curve during the summer season and climatic conditions follow a more erratic evolution. With predawn leaf water potentials (PLWP) serving as a proxy for soil water content and midday stem water potentials (SWP) reflecting water supply and climatic conditions, it becomes possible to separate the effect of soil water content and climatic conditions on vine water status. Direct use of PLWP measurements on soils with heterogeneous water content is not an option because it is less accurate than SWP measurements and a late-night measurement is not practical. The objectives of this study are (i) to provide a model that separates the effect of soil water content from the effect of climatic conditions on the SWP value and (ii) to standardize the SWP value to a value under predefined reference climatic conditions to better reflect soil water availability, and to compare SWP values under different climatic conditions.

Material and methods – Vine water status was assessed on three soil types in the AOC Saint-Émilion in 2015 and on 5 soil types in the AOC Margaux in 2018. Over the growing season, SWP and PLWP were measured on mature leaves using a pressure chamber.

Results – New models with easily accessible variables can separate the effect of soil water content from the effect of climatic conditions on the SWP values. The measurement of the PLWP is no longer necessary. More research is needed however to understand the changing relationship between SWP and daily maximum temperature over time. SWP values can be brought back to a theoretical value representative of standard climatic conditions. This standardization can be particularly interesting in a context of climate change, where a greater variability of climatic conditions between years is observed. A more precise interpretation allows the winegrower and consultant to more adequately decide on adaptations to implement in both the short- and long term to ensure yields and grape quality.

Download the PDF

DOI:

Publication date: September 28, 2023

Issue: GiESCO 2019

Type: Poster

Authors

Bruno SUTER1,2, Roberta TRIOLO1, David PERNET1, Zhanwu DAI2, Cornelis VAN LEEUWEN2

1 SOVIVINS, Site Montesquieu, 4 allée Isaac Newton, 33650 Martillac, France
2 EGFV, Bordeaux Sciences Agro, INRA, Univ. of Bordeaux, ISVV, 33882 Villenave d’Ornon, France

Contact the author

Keywords

grapevine water status, stem water potential, predawn leaf water potential, maximum temperature, vapour pressure deficit, evapotranspiration

Tags

GiESCO | GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Characterization of 25 white grape varieties from the variety collection of ICVV (D.O.Ca.Rioja, Spain)

The effects of climate change produce an increase in sugar concentration and a decrease in acidity, without reaching the optimum grape phenolic maturity [1]. The aim of this work was to characterize 25 white grape varieties
Read More

Wine labelling with the list of ingredients: context, consumer’s perception and future challenges

In this video recording of the IVES science meeting 2024, Stéphane La Guerche (Œnoppia, Paris, France) speaks about wine labelling with the list of ingredients: context, consumer’s perception and future challenges. This presentation is based on an original article accessible for free on IVES Technical Reviews.

Read More

The plantation frame as a measure of adaptation to climate change

The mechanization of vineyard work originally led to a reduction in planting densities due to the lack of machinery adapted to the vineyard. The current availability of specific machinery makes it possible to establish higher planting densities. In this work, three planting densities (1.40×0.80 m, 1.80×1 m and 2.20×1.20 m, corresponding to 8928, 5555 and 3787 plants/ha respectively) were studied with four varieties autochthonous of Galicia (northwestern Spain): Albariño and Treixadura (white), Sousón and Mencía (red). The vines were trained in a vertical shoot positioning system using a single Royat cordon, and pruned to spurs with two buds each. Agronomic data (yield, pruning wood weight, Ravaz index) and oenological data in must were collected. The higher planting density (1.40×0.80 m) had no significant effect on grape yield per vine in white varieties, although production per hectare was much higher due to the greater number of plants. In red varieties, this planting density resulted in a significantly lower production per vine, compensated by the greater number of plants. In addition, it significantly reduced the Brix degree in the must of the Albariño, Treixadura and Sousón varieties, and increased the total acidity in the latter two and Mencía. It also caused an increase in extractable and total anthocyanins and IPT in red grapes. The effects of high planting density on grapes are of great interest for the adaptation of varieties in the context of climate change. In the future, it could be advisable to modify the limits imposed by the appellations of origin on the planting density of these varieties in order to obtain more balanced wines.

Read More

Déterminisme de l’effet terroir: influence de la surface foliaire primaire de la vigne en début de cycle sur le potentiel vendange

ln the Mid-Loire Valley, in France, for the fast twenty years a network of experimental plots has been used to analyse the terroir effect on the behaviour of the Cabernet franc variety of grape. The study of the primary leaf area (SFI) for several vintages shows that it differs greatly from one terroir to another.

Read More

Cartography of « Terroir Units » is a Tool to Improve the Ré Island Vineyard Management (France)

A study of « terroirs » was achieved from 2003 to 2005 in the whole vineyard of the Ré island (17, France). Over more than 1,990 ha, a cartography at the 1/10.000 scale, including characterization of climatic, pedological, geological and hydrogeological components of « Basic Terroir Units » (B.T.U.) was made. Also, a survey among wine growers was conducted. All data were treated together in a G.I.S. connected to a data base. 22 kinds of map were built (B.T.U. and components, soil water reserve, vine functioning potentials, varieties, rootstocks, viticultural practices and soil management).

Read More