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…

Sustaining wine identity through intra-varietal diversification

With contemporary climate change, cultivated Vitis vinifera L. is at risk as climate is a critical component in defining ecologically fitted plant materiel. While winegrowers can draw on the rich diversity among grapevine varieties to limit expected impacts (Morales-Castilla et al., 2020), replacing a signature variety that has created a sense of local distinctiveness may lead to several challenges. In order to sustain wine identity in uncertain climate outcomes, the study of intra-varietal diversity is important to reflect the adaptive and evolutionary potential of current cultivated varieties. The aim of this ongoing study is to understand to what extent can intra-varietal diversity be a climate change adaptation solution. With a focus on early (Sauvignon blanc, Riesling, Grolleau, Pinot noir) to moderate late (Chenin, Petit Verdot, Cabernet franc) ripening varieties, data was collected for flowering and veraison for the various studied accessions (from conservatory plots) and clones. For these phenological growing stages, heat requirements were established using nearby weather stations (adapted from the GFV model, Parker et al., 2013) and model performances were verified. Climate change projections were then integrated to predict the future behaviour of the intra-varietal diversity. Study findings highlight the strong phenotypic diversity of studied varieties and the importance of diversification to enhance climate change resilience. While model performances may require improvements, this study is the first step towards quantifying heat requirements of different clones and how they can provide adaptation solutions for winegrowers to sustain local wine identity in a global changing climate. As genetic diversity is an ongoing process through point mutations and epigenetic adaptations, perspective work is to explore clonal data from a wide variety of geographic locations.

Effect of Candida zemplinina oak chips biofilm on wine aroma profile

Candida zemplinina (synonym Starmerella bacillaris) is frequently isolated in grape must in different vitivinicultural areas. The enological significance of C. zemplinina strains used in combination with S. cerevisiae has been demonstrated, being wines produced by the above-mixed starter, characterized by higher amounts of glycerol and esters.

The exploitation of Croatian grapevine genetic resources for the breeding of new resistant cultivars 

Croatian viticulture is mainly based on native grapevine varieties susceptible to various diseases and pests, which leads to unsustainable use of large amounts of pesticides. The sustainable development of viticulture in the future will only be possible by increasing the resistance of the grapevine through the development of new resistant varieties. Breeding programs have been launched in the leading wine-growing countries to develop resistant varieties possessing high-quality levels. Native cultivars from Croatia are not included in the breeding programs of other countries.

Impact of heating must before fermentation on Chardonnay wines

Prefermentation steps of white winemaking are very important for controlling the stability and the sensory attributes of wines. Usually musts are clarified by cold settling to prevent the start of the fermentation, before racking big lees and thus limiting the appearance of vegetable or reduction off flavour while favouring an aromatic expression with low turbidity. Besides, to reach the protein stability, some white wines further require a bentonite fining, sometimes associated with negative effects on the sensory quality. This study aims to know the impact of musts heating after pressing on a Chardonnay wine in northern conditions by comparison with a classic cold racking of the must.

Profiling and evaluating wine lees by-products from various yeast strains against grapevine pathogens

Wine lees are the sediment that settles at the bottom of wine barrels, tanks, or bottles during the winemaking process and represent the second most significant by-product of wineries.