GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Staying hydrated – not easy when it’s hot!

Staying hydrated – not easy when it’s hot!

Abstract

Context and purpose of the study – Heat and drought episodes during the growing season are becoming more frequent and more severe in many of the world’s grape‐growing regions. However, the responses of grapevines to a combination of these stress factors are incompletely understood, which hampers the implementation of deficit irrigation and heat mitigation strategies. Our team is investigating impacts of water deficit and temperature alone or in combination on physiology, growth, fruit production and composition of different grape cultivars. In addition, we are also testing different deficit irrigation strategies and novel approaches to canopy heat mitigation.

Material and methods ‒ Experiments are conducted with both field‐ and pot‐grown cultivars of own‐ rooted wine grapes in an arid climate. Drydown and rewatering cycles were applied to 18 cultivars in a vineyard, and changes in soil moisture, leaf water potential, and stomatal conductance were monitored during 4 growing seasons. In another experiment, pot‐grown Cabernet Sauvignon and Riesling vines were exposed in environmentally controlled growth chambers to episodes of water stress, heat stress, and combined water and heat stress, followed by recovery periods. Changes in growth, leaf physiology, and fruit composition were compared with non‐stressed control vines. Finally, a novel mist‐type evaporative cooling system was installed in a Cabernet Sauvignon vineyard and is currently being tested for its ability to mitigate heat stress while maintaining fruit quality.

Results ‒All cultivars tested in the vineyard decreased their leaf water potential as the soil dried. Some cultivars behaved in classic anisohydric fashion, while others only decreased their leaf water status once soil moisture had declined below a threshold, and yet others showed highly variable responses. Irrespective of their hydraulic behavior, all cultivars also responded to soil drying by decreasing stomatal conductance. In the growth chambers, water stress dominated the responses of shoot growth and leaf physiology in both cultivars, but heat stress exacerbated the adverse impact of water stress. By contrast, heat stress dominated the responses of fruit composition, reducing titratable acidity and increasing the pH and total soluble solids. The evaporative cooling system effectively controlled canopy temperatures during heat waves with a minimum supply of water and without adverse effects on disease incidence, fruit yield, and composition. 

DOI:

Publication date: June 19, 2020

Issue: GiESCO 2019

Type: Article

Authors

Markus KELLER (1), Joelle MARTINEZ (1), Esther HERNÁNDEZ‐MONTES (1), Yun ZHANG (1,2), Ben‐Min CHANG (1)

(1) Irrigated Agriculture Research and Extension Center, Washington State University, 24106 N. Bunn Road, Prosser, WA 99350, USA
(2) Ste. Michelle Wine Estates, 660 Frontier Road, Prosser, WA 99350, USA

Contact the author

Keywords

Heat stress, water stress, irrigation, anisohydric, isohydric, gas exchange

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Building of a hierarchy of wines based on terroirs: an initiative from the producers of Muscadet

The Muscadet area is situated in the southeast of Nantes, close to the Atlantic coast. It constitutes the western extension
of the French vineyard “Loire Valley”. The Muscadet is renowned and often spontaneously linked to a white wine.
However it remains misconceived as an ordinary wine, lacking authenticity.

How the physical components of the terroir can differently intervene in French wines DPO definitions.Example of Côte de Nuits in Burgundy

European regulations describe what elements must be given in the specifications of DPO determination ; mainly production conditions, links between quality and products characteristics and the physical traits of the production area. These elements are given in the “link to terroir” paragraph relating natural and human factors, detailed product characteristics linked to the geographical area and at last interactions between product originality and the geographical area.

Vignobles sur les pentes en Bourgogne : l’aube d’un nouveau modèle de l’Antiquité au Moyen Âge

La découverte d’une vigne gallo-romaine en plaine à Gevrey-Chambertin (Côte-d’Or) constitue un point important pour la compréhension de la construction des terroirs viticoles de Bourgogne. Sa situation en plaine constitue pour nous le point de départ d’une large réflexion sur la mise en place du modèle de viticulture de coteau qui prévaut en Bourgogne et sur les facteurs de ce changement de norme de qualité viticole. Les sources mobilisées pour cette approche interdisciplinaire et diachronique sont géomorphologiques, archéologiques et textuelles.

Everything else, it’s work ”Socio-cultural dimensions of terroir among Bordeaux winemakers

In 2010, the OIV adopted a resolution that defines ‘terroir’. The OIV definition understands terroir as the result of the interactions between the physical specificities of a space and human labor, with an emphasis on the subsequently produced collective knowledge (OIV-VITI 333-2010); by doing so, it alludes to the social and cultural dimensions of terroir.

Swiss program for the creation of fungal disease resistant grape varieties in Switzerland

Grapevine breeding is part of the research program of Agroscope in Switzerland since 1965. From 1965 to 1995, the aim of the Vitis vinifera crosses was to obtain a high resistance to grey rot (Botrytis cinerea), one of the most virulent fungal pathogens in the Swiss vineyard. In 2021, the grape varieties released from this first breeding program covered 936 ha of the 15’000 ha of the Swiss vineyard.
In 1996, a second breeding program aimed at obtaining, by classical interspecific hybridization, grape varieties resistant to downy mildew (Plasmopara viticola) and powdery mildew (Erisyphe necator) and less sensitive to grey rot (Botrytis cinerea). In order to accelerate and make the selection process more reliable, an early biochemical test was developed based on the natural defense mechanisms of the vine against downy mildew (stilbene phytoalexins). The synthesis of stilbenes (i.e., resveratrol and its oxidized dimers - and -viniférine) and pterostilbenes (methylated derivative) is among the most efficient induced defense mechanisms of grapevine against fungal pathogens on both the leaves and the clusters.