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…

LC-HRMS data analysis of natural polymer homologue series Application on wine neutral oligosaccharides

Although oligosaccharides have much impact both on health (prevention of diabetes, cardiovascular disease), and on the perception of wine (sweetness, astringency, acidity or bitterness), information on their composition in wine is still limited.

Climate change impacts: a multi-stress issue

With the aim of producing premium wines, it is admitted that moderate environmental stresses may contribute to the accumulation of compounds of interest in grapes. However the ongoing climate change, with the appearance of more limiting conditions of production is a major concern for the wine industry economic. Will it be possible to maintain the vineyards in place, to preserve the current grape varieties and how should we anticipate the adaptation measures to ensure the sustainability of vineyards? In this context, the question of the responses and adaptation of grapevine to abiotic stresses becomes a major scientific issue to tackle. An abiotic stress can be defined as the effect of a specific factor of the physico-chemical environment of the plants (temperature, availability of water and minerals, light, etc.) which reduces growth, and for a crop such as the vine, the yield, the composition of the fruits and the sustainability of the plants. Water stress is in many minds, but a systemic vision is essential for at least two reasons. The first reason is that in natural environments, a single factor is rarely limiting, and plants have to deal with a combination of constraints, as for example heat and drought, both in time and at a given time. The second reason is that plants, including grapevine, have central mechanisms of stress responses, as redox regulatory pathways, that play an important role in adaptation and survival. Here we will review the most recent studies dealing with this issue to provide a better understanding of the grapevine responses to a combination of environmental constraints and of the underlying regulatory pathways, which may be very helpful to design more adapted solutions to cope with climate change.

New varieties descendant from Monastrell with lower sugar and high phenolic content adapted to warm climates

Given that climate change is a continuous process, it is necessary to constantly search for new strategies that help the viticulturist sector to mitigate its consequences. All adaptation strategies will have a greater or lesser effect that in turn will be marked by the times of action. As a long-term action, a genetic breeding program to obtain new varieties descendant from Monastrell has been developed in the Region of Murcia (more specifically, in the IMIDA Research Center) since 1997. In this program, new red varieties have been developed through directed crosses of the Monastrell variety with other varieties such as Cabernet Sauvignon, Tempranillo and Syrah.

Predictive Breeding for Wine Quality: From Sensory Traits to Grapevine Genome

New pathogen resistant varieties allow an efficient and greatly reduced use of fungicides. These new varieties promise, therefore, an enormous potential to reach the European Green Deal aim of a 50% reduction of pesticides in EU agriculture by 2030.

Applications pratiques du zonage vitivinicole

Le zonage vitivinicole présente toute une série d’applications pratiques. Son importance est en train d’augmenter, soit en fonction des moyens techniques chaque fois plus performants, qui rendent possible le développement des zonages de plus en plus intégrées, consistants et utiles, soit en fonction d’un marché de plus en plus mondialisé. L’article situe la contribution du zonage au niveau de la production vitivinicole et du développement du territoire.