Terroir 2014 banner
IVES 9 IVES Conference Series 9 A generic method to analyze vine water deficit continuously

A generic method to analyze vine water deficit continuously

Abstract

In the context of global warming, water scarcity is becoming an increasing issue worldwide. However, the reference method to characterize vine water deficit is based on water potential measurement, which is a destructive and discontinuous method. The current climatic context emphasizes the need for more precise and more continuous vineyard water use measurements in order to optimize irrigation and vine water deficit monitoring.

Our work proposes a quantitative method to characterize vine water deficit variations in a continuous fashion. Combining sap flow and climatic raw data, the framework uses expert knowledge and mathematical modeling to characterize dry soil crop coefficient (KcB) and automatically compute a daily water deficit index Ks. As a case study we used an experimental design set in French vineyards where contrasted vine water deficit profiles were obtained by using differential irrigation treatments.

We analyzed Tr/ETref ratio variations to identify the timing and value of maximal KcB. After that preliminary step, we computed and aggregated Ks profiles for each treatment and compared irrigation effects on Ks profiles. Because sap flow and climatic sensors are installed outdoor, determination of maximal KcB value is particularly sensitive to environmental variations. As such, we studied the effect of measurement uncertainties on KcB computation and Ks profile by imposing variations in the timing and value of KcB. Implications and perspectives to improve irrigation practices are discussed.

DOI:

Publication date: August 18, 2020

Issue: Terroir 2014

Type: Article

Authors

Scholasch T. (1), Charnomordic B. (2), Hilgert N. (2)

(1) Fruition Sciences, SAS. MIBI, 672 rue du Mas de Verchant 34000 Montpellier,France 
(2) INRA-SupAgro, UMR 729 MISTEA, F-34060 Montpellier, France 

Keywords

sap flow, Ks, water use, irrigation, dry soil crop coefficient

Tags

IVES Conference Series | Terroir 2014

Citation

Related articles…

Update knowledge about the presence of condensed tannins in grapes and their contributions to astringency perception

Condensed tannin is a principle group of polyphenol compounds derived from grape, greatly contributing to the bioactivity and the sensory perception of wine. Condensed tannins present as a heterogeneous mixture in nature involving various degrees of both polymerization and galloylation. Even though multiple attempts focusing on fractionation of grape condensed tannins by solid-phase have been conducted over the past decades, few individual tannins have been purified and identified. Hence, our knowledge on grape and wine condensed tannin moleculars has to be limited at the several known monomeric, dimeric and trimeric proanthocyanidins

IBMP-Polypenol interactions: Impact on volatility and sensory perception in model wine solution

3-Isobutyl-2-methoxypyrazine (IBMP) is one of the key molecules in wine aroma with a bell pepper aroma and a very low threshold in wine, 1-6 ng/L for white wine and 10-16 ng/L in red wine1. The differences in these thresholds are likely due to IBMP-non volatile matrix interactions. It has indeed been shown that polyphenols may influence the volatility of flavor compounds2. In the present study, we focus on IBMP-polyphenols interactions in relation to volatility and sensory perception in model wine solution. Methods: 1. GC-MS Static Headspace Analysis: Samples were analyzed by Static headspace analysis with an Agilent 7890A gas chromatograph coupled to HP 5975C mass spectrometry detector (Agilent Technologies, Santa Clara, CA, USA).

The role of soil water holding capacity and plant water relations in zone/terroir expression

The spatial variability in soil type and depth and water holding capacity is very high in many viticultural regions of the world. Differences in rooting depths and water extraction profiles and their seasonal dynamics add additional variability and it is extremely difficult to deduct direct causal relationships between these factors and fruit

Polyphenols in kombucha: impact of infusion time on extraction and investigation of their behavior during “fermentation”

Kombucha is a non-alcoholic beverage made of sugared tea that is transformed by a symbiotic consortium of yeasts and bacteria. Polyphenols are expected to be responsible of several health benefits attributed to kombucha consumption, among other metabolites. This study investigated the impact of tea infusion time and of kombucha “fermentation”, on total phenolic content,

Study of the impact of nitrogen additions and isothermal temperature on aroma production in oenological fermentation

Nitrogen and temperature are two important factors that influence wine fermentation and volatile compounds production. Among the different compounds present in the must, nitrogen is an essential nutrient for the management of the fermentation kinetics but it also plays an important role in the synthesis of fermentative aromas. To address the problems related to nitrogen deficiencies, nitrogen additions during alcoholic fermentation have been developed.