Terroir 2020 banner
IVES 9 IVES Conference Series 9 International Terroir Conferences 9 Terroir 2020 9 History and innovation of terroir 9 Building new temperature indexes for a local understanding of grapevine physiology

Building new temperature indexes for a local understanding of grapevine physiology

Abstract

Aim: Temperature corresponds to one of the main terroir factors influencing grapevine physiology, primarily evidenced by its impact on phenology. Numerous studies have aimed at expressing time with thermal indices such as growing degree days (GDD) and have thus enabled a better modelling of grapevine responses to temperature. However, some works have highlighted the need to adapt GDD to the considered pedo-climatic context and grape variety or to refine the time step at which temperature variables are computed. The present study aims to investigate the hypothesis that grapevine response to temperature depends on the production context, ie. plant material, pedo-climate, topography, orientation and cultural practices, and that thermal indices should then be locally adapted. 

Methods and Results: GDD with different base temperatures but also other indices based on other algebraic equations on daily average temperature were calculated starting from the bud break date and using data from weather stations located in the Bordeaux region (France), California (USA) and Israel. The dates of flowering and veraison were expressed according to each of these indices for three commercial blocks located near each weather station. For each block, the relative differences in the flowering and veraison dates were calculated for any couple of years and summed squared. The number of studied years considered ranged from fifteen to five depending on the blocks. The relative difference between two dates was computed as their difference in index-related degrees divided by the average index-related amount of degrees to reach veraison. The thermal index which minimizes the sum of the relative differences of flowering and veraison dates for all the years of the same block is considered to best illustrate the temperature local effect. As such, this local effect includes both grapevine physiological response to temperature and the difference between the weather station data and the conditions actually experienced by the vines.

Dates of flowering and veraison of all years coincide when expressed in a given thermal index for most of the blocks. The hypothesis whereby temperature is a predominant factor in grapevine phenology may thus be confirmed. Moreover, the thermal indices allowing such an adjustment are different between blocks of different locations, thus demonstrating that temperature effects on grapevine phenology are better captured when considered according to locally calibrated indices. 

Conclusion:

Temperature effects may be better captured by different thermal indices depending on the local context. 

Significance and Impact of the Study: In a precision viticulture context, a growing access to local and higher resolution weather data and grapevine observations enables models to be used locally. The present study therefore corresponds to a first attempt to highlight the importance of calibrating a local thermal index to improve the performance and operational relevance of any temperature-based model.

DOI:

Publication date: March 23, 2021

Issue: Terroir 2020

Type: Video

Authors

Cécile Laurent1,2,3*, Thibaut Scholasch1, Bruno Tisseyre3, Aurélie Metay2

1Fruition Sciences, Montpellier, France
SYSTEM, Univ Montpellier, CIHEAM-IAMM, CIRAD, INRAE, Institut Agro, Montpellier, France
3ITAP, Univ. Montpellier, Institut Agro, INRAE, Montpellier, France

Contact the author

Keywords

Local thermal index, precision viticulture, terroir factors

Tags

IVES Conference Series | Terroir 2020

Citation

Related articles…

PHENOTYPIC DIVERSITY AND BIO-PROTECTION CAPABILITY OF METSCHNIKOWIA SP. IN OENOLOGY

Nowadays, the trend is to reduce the use of chemical inputs in the food sector, including in oenology. One of the inputs widely used in the wine making process are sulfites, for its several properties: antimicrobial and antioxidiant. This use isn’t without consequences on consumer’s health and environment, it can lead for example to allergic reactions and pollution. To limit the addition of chemical inputs, microbial alternatives are used. It consists to inoculate in grape must, a micro-organism able to inhibit the growth of the negative indigenous flora during the phase before the fermentation and to guarantee the sensory qualities of wines.

Study of wine-growing land (“terroir”) characteristics in the canton of Vaud (Switzerland): ecophysiological behaviour of the vine (cv. Chasselas)

A study of the physiological and agronomical behaviour of the vine (cv. Chasselas) was conducted between 2001 and 2003 by the Swiss Federal Research Station for Plant Production at Changins (Agroscope RAC Changins) on various wine-growing farms (terroirs) in the Canton of Vaud (Switzerland), as part of a study project on Vaudois

Biovi: a research program for reducing chemical input in vine and wine

Decrease of chemical inputs during vine management and winemaking is of great importance from a political and societal point of view. In our ongoing project we propose alternative tools to chemicals in the vineyard and the cellar. We have compared a conventional vineyard protection strategy to an alternative strategy using copper and biocontrol products (Biocontrol) against downy

Current climate change in the Oplenac wine-growing district (Serbia)

Serbian autochthonous vine varieties Smederevka (for white wines) and Prokupac (for rosé and red wines) are the primary representatives of typical characteristics of wines and terroir of numerous wine-growing areas in Serbia. In the past, these varieties were the leading vine varieties, however, as the result of globalization of winemaking and the trend of consumption of wines from widely prevalent vine varieties, they were replaced by introduced international varieties. Smederevka and Prokupac vine varieties are characterized by later time of grape ripening, and relative sensitivity to low temperatures. Climate conditions can be a restrictive factor for production of high-quality grapes and wine and for the spatial spreading of these varieties in hilly continental wine-growing areas.
This paper focuses on the spatial analysis of changes of main climate parameters, in particular, analysis of viticultural bioclimatic indices that were determined for the purposes of viticulture zoning of wine-growing areas in the period 1961-2010, and those same parameters determined for the current, that is, referential climate period (1988-2017). Results of the research, that is, analysis of climate changes indicate that the majority of examined climate parameters in the Oplenac wine-growing district improved from the perspective of Smederevka and Prokupac vine varieties. These studies of climate conditions indicate that changes of analyzed climate parameters, that is, bioclimatic indices will be favorable for cultivation of varieties with later grape ripening times and those more sensitive to low temperatures, such as the autochthonous vine varieties Smederevka and Prokupac, therefore, it is recommended to producers to more actively plant vineyards with these varieties in the territory of the Oplenac wine-growing district.

Post-plant nematicide timing for northern root-knot nematode in Washington wine grapes

Vigor declines in older vineyards and poor vine establishment in replant situations have been attributed to plant-parasitic nematodes. The northern root-knot nematode, Meloidogyne hapla, is the most prevalent plant-parasitic nematode species found in Washington wine grape vineyards. Management for nematodes in established vineyards is limited to the application of post-plant nematicides. We are evaluating new nematicides that are currently not registered in grape for their efficacy in controlling M. hapla and a part of that evaluation includes improving the alignment of nematicide application timing with the vulnerable second-stage juvenile (J2) life stage of M. hapla.