terclim by ICS banner
IVES 9 IVES Conference Series 9 Mechanisms involved in the heating of the environment by the aerodynamic action of a wind machine to protect a vineyard against spring frost

Mechanisms involved in the heating of the environment by the aerodynamic action of a wind machine to protect a vineyard against spring frost

Abstract

One of the main consequences of global warming is the rise of the mean temperature. Thus, the heat summation by the plants begins sooner in the early spring, and by cumulating growing degree-days, phenological development tends to happen earlier. However, spring frost is still a recurrent phenomenon causing serious damages to buds and therefore, threatening the harvests of the winegrowers. The wind machine is a solution to protect fruit crops against spring frost that is increasingly used. It is composed of a 10-m mast with a blowing fan at its peak. By tapping into the strength of the nocturnal thermal inversion, it sweeps the crop by propelling warm air above to the ground. Thus, stratification is momentarily suppressed. Furthermore, the continuous action of the machine, alone or in synergy, or the addition of a heater allow the bud to be bathed in a warmer environment. Also, the punctual action of the tower’s warm gust reaches the bud directly at each rotation period. All these actions allow the bud to continuously warm up, but with different intensities and over a different period. Although there is evidence of the effectiveness of the wind machines, the thermal transfers involved in those mechanisms raise questions about their true nature. Field measurements based on ultrasonic anemometers and fast responding thermocouples complemented by laboratory measurements on a reduced scale model allow to characterize both the airflow produced by the wind machine and the local temperature in its vicinity. Those experiments were realized in the vineyard of Quincy, in the framework of the SICTAG project. In the future paper, we will detail the aeraulic characterization of the wind machine and the thermal effects resulting from it and we will focus on how the wind machine warms up the local atmosphere and enables to reduce the freezing risk.

Download the PDF

DOI:

Publication date: May 31, 2022

Issue: Terclim 2022

Type: Poster

Authors

Clara Le Cap1,2,3, Johan Carlier2, Hervé Quénol3, Dominique Heitz2 and Emmanuel Buisson1

1Weather Measures, Clermont-Ferrand, France
2INRAE, UR OPAALE, Rennes, France
3CNRS, UMR 6554 LETG, Université Rennes 2, Rennes, France

Contact the author

Keywords

spring frost, wind machine, thermal processes, vineyard, protection

Tags

IVES Conference Series | Terclim 2022

Citation

Related articles…

THE ODORIFEROUS VOLATILE CHEMICALS BEHIND THE OXIDATIVE AROMA DEGRADATION OF SPANISH RED WINES

It is a well-established fact that premature oxidation is noxious for wine aromatic quality and longevity. Although some oxidation-related aroma molecules have been previously identified, there are not works carrying out systematic research about the changes in the profiles of odour-active volatiles during wine oxidation.

Read More

The moment of preharvest elicitor application influence its final effect on winegrapes quality

Phenolic compounds are secondary metabolites of grapes. Plants produce a wide variety of this type of metabolites through diverse biosynthesis pathways and their production is sometimes a response to external stimuli, either environmental or biotic stresses. Some of them may act as chemical defenses against pathogens or herbivores and their synthesis is increased when the attack exists. However, it is remarkable that the synthesis of these interesting compounds can be activated even when the stimulus is not present, with the use of elicitors. These are substances that when applied exogenously trigger the biosynthetic pathways conducting to the synthesis of these defense compounds.

Read More

Viticulture between adaptation and resilience: the role of the Italian long-term observatories for vineyard energy, water and carbon budgets

Viticulture is exposed to a range of new stressors, that are challenging its sustainability and disrupting famous and well-established production regions. Steady increase of average temperature, recurring heat waves, altered rainfall seasonal distribution, drought spells, increased pathogens pressure, they all mix up with increased frequency, making every growing season a special challenge and calling for new approaches to cope with worrying scenarios.

Read More

The evolution of wine tourism: trends, challenges and opportunities for the future

The wine tourism industry has experienced significant transformation over the past years, accelerated by the COVID-19 pandemic.

Read More

ASSESSMENT OF ‘DOLCETTO’ GRAPES AND WINES FROM DIFFERENT AREAS OF OVADA DOCG

Dolcetto (Vitis vinifera L.) is one of the traditionally cultivated varieties in Piedmont (north-east Italy). Dolcetto wines have long been associated with local consumption and they are little known internationally. In particular, the Ovada area (south-east Piedmont), even if it represents a small share of the regional PDO Dolcetto production, is one of the oldest and vocated territory, giving wine also suitable for aging. In this study, the basic composition and phenolic content of Dolcetto grapes for Ovada DOCG wines have been investigated in three different vintages (2020-2022), as well as the main aspects of the derived commercial and experimental wines (basic parameters, phenolics, volatile compounds, sensory properties).

Read More