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


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.


Publication date: September 28, 2023

Issue: GiESCO 2019

Type: Poster


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

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

Contact the author


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


GiESCO | GiESCO 2019 | IVES Conference Series


Related articles…

Physiological and growth reaction of Shiraz/101-14 Mgt to row orientation and soil water status

Advanced knowledge on grapevine row orientation is required to improve establishment, management and outcomes of vineyards on terroirs with different environmental conditions (climate, soil, topography) and in view of a future change to more extreme climatic conditions. The purpose of this study was to determine the combined effect of row orientation, plant water status and ripeness level on the physiological and viticultural reaction of Shiraz/101-14 Mgt.

Effects of mechanical leafing and deficit irrigation on Cabernet Sauvignon grown in warm climate of California

San Joaquin Valley accounts for 40% of wine grape acreage and produces 70% of wine grape in California. Fruit quality is one of most important factors which impact the economical sustainability of farming wine grapes in this region. Due to the recent drought and expected labor cost increase, the wine industry is thrilled to understand how to improve fruit quality while maintaining the yield with less water and labor input. The present study aims to study the interactive effects of mechanical leafing and deficit irrigation on yield and berry compositions of Cabernet Sauvignon grown in warm climate of California.

The effects of cane girdling on berry texture properties and the concentration of some aroma compounds in three table grape cultivars

The marketability of the table grapes is highly influenced by the consumer demand; therefore the market value of the table grapes is mainly characterized by its berry size, colour, taste and texture. Girdling could cause accumulation of several components in plants above the ringing of the phloem including clusters and resulting improved maturity. The aim of the experiments was to examine the effect of girdling on berry texture characteristics and aroma concentration.

Application of a fluorescence-based method to evaluate the ripening process and quality of Pinot Blanc grape

The chemical composition of grape berries at harvest is one of the most important factors that should be considered to produce high quality wines. Among the different chemical classes which characterize the grape juice, the polyphenolic compound, such as flavonoids, contribute to the final taste and color of wines. Recently, an innovative non-destructive method, based on chlorophyll fluorescence, was developed to estimate the phenolic maturity of red grape varieties through the evaluation of anthocyanins accumulated in the berry skin. To date, only few data are available about the application of this method on white grape varieties.

Different yield regulation strategies in semi-minimal-pruned hedge (SMPH) and impact on bunch architecture

Yields in the novel viticulture training system Semi-Minimal-Pruned Hedge (SMPH) are generally higher compared to the traditional Vertical Shoot Positioning (VSP). Excessive yields have a negative impact on the vine and wine quality, which can result in substantial losses in yield in subsequent vintages (alternate bearing) or penalties in fruit quality. Therefore yield regulation is essential. The bunch architecture in SMPH differs from VSP. Generally there is a higher amount but smaller bunches with lower single berry weights in SMPH compared to VSP.