Terroir 2004 banner
IVES 9 IVES Conference Series 9 Climatic zoning of viticultural production periods over the year in the tropical zone: application of the methodology of the Géoviticulture MCC system

Climatic zoning of viticultural production periods over the year in the tropical zone: application of the methodology of the Géoviticulture MCC system

Abstract

L’objectif de cette recherche est le zonage climatique des périodes viticoles de l’année dans la Vallée du São Francisco, région brésilienne productrice de vins située en climat tropical semi-aride. Dans cette région, la production peut être échelonnée sur tous les mois de l’année. La région est placée sur climat viticole à variabilité intra-annuelle, qui correspond aux régions qui, sur des conditions climatiques naturelles, changent de classe de climat viticole en fonction de la période de l’année au cours de laquelle le raisin peut être produit. La méthodologie adoptée est celle du Système de Classification Climatique Multicritères Géoviticole (Système CCM Géoviticole) (Tonietto & Carbonneau, 2004), en utilisant les fonctionnalités de modulation des indices (indices homologues appliqués sur la phénologie locale des cépages). Les indices climatiques viticoles du Système (thermique, nycthermique et hydrique) ont été adaptés aux conditions biologiques du cépage Syrah de la région, qui présente un cycle moyen débourrement-récolte (d-r) de 4 mois. L’étude utilise une base de données climatiques journalières de la période 1976-2002, avec la simulation de 36 récoltes théoriques par an (une récolte théorique a chaque décade), soit un totale de 972 sur l’ensemble de la période étudiée. Ainsi, l’Indice Héliothermique (IH12d) à été calculé sur 4 mois tout au long de l’année. L’Indice de Fraîcheur des Nuits (IF3d) a été calculé sur les 3 décades précédentes la date théorique de récolte (période de maturation). La quantité de pluie en période de maturation (P3d) a également été prise en compte en fonction des effets sur l’incidence de pourriture. Les résultats ont permis de caractériser 3 périodes climatiques viticoles distincts dans l’année : Période “a” – conditions thermiques moins chaudes pendant le cycle d-r pour l’IH12d, conditions nycthermiques (IF3d) plus fraîches et très sec (P3d) en période de maturation ; Période “b” – climat intermédiaire entre la période “a” et “c” pour l’IF3d et l’IH12d et sec à très sec pour P3d (la période “b” peut être subdivisée en 2 sous-périodes : l’une que s’initie en sortant de la période chaude et humide “c”, avec une réserve hydrique utile au niveau du sol, et évolue avec la chute des températures ; et l’autre sous-période qui débute avec l’augmentation des températures et que finie juste avant la rentrée de la période humide “c”) ; Période “c” – Le plus chaud pour l’IF3d et l’IH12d et sub-humide pour P3d. Les résultats montrent que la production de raisin de cuve pour un même cépage présente des caractéristiques potentielles distinctes en fonction des périodes de production “a”, “b” et “c”. D’une façon générale, la période “c” est la plus susceptible a une maturité du raisin incomplète en fonction du risque de pourriture (pluie et température élevée), qui peuvent amener à une récolte avant la complète maturation du raisin. Déjà les périodes “a” et “b” sont les plus aptes a une bonne maturation du raisin. La période “a” est celle qui présente le moindre risque de pluie et des températures les plus fraîches, avec la possibilité du contrôle total de la disponibilité hydrique du sol par l’irrigation. La probabilité d’occurrence des indices climatiques à été caractérisé par décade et par quartile comme information d’aide à la décision (risque ou avantages) des périodes de production. Des études complémentaires, notamment l’estimation de la réserve hydrique potentielle (Indice de Sécheresse – IS) du sol seront développées. On peut conclure que le concept de climat viticole à variabilité intra-annuelle du Système CCM Géoviticole peut être utilisé comme élément de zonage pour l’établissement, dans un même vignoble, des périodes de l’année avec un potentiel climatique supérieur de production de raisin de cuve. Ce critère climatique va être utilisé dans le zonage intégré de la région, notamment avec les facteurs édaphiques.

The objective of this research is the viticultural climatic zoning of the production periods over the year in the São Francisco Valley, a Brazilian grape-growing region located in semi-arid tropical climate. In this region, the production can be spread over all months of the year. The region is situated in climate with intra-annual variability, that corresponds to the regions which, under natural climatic conditions, change the class of viticultural climate according to the period of the year during which the grape is produced. The methodology adopted is that of the Géoviticulture Multicriteria Climatic Classification System (Géoviticulture MCC System) (Tonietto & Carbonneau, 2004), employing the modulation functions of the indices. The viticultural climatic indices of the System have been adapted to the biological conditions of the Syrah variety, which has an average cycle of 4 months from bud burst to harvest (d-r) in the region. The study is based on a daily climate database from 1976 through 2002, simulating 36 theoretic harvests per year (one theoretic harvest at every ten 10 days), amounting to a total of 972 harvests in the whole period covered by the study. In this way, the Heliothermal Index (HI12d) was calculated over 4 months throughout the year. The Cool Night Index (IF3d) was calculated over the 30 days that preceded the theoretic harvest (maturation period). The amount of rain (P3d) in the maturation period was equally been taken into account according to the potential effect of the incidence of bunch rotting. The results have allowed to distinguish 3 climatic viticultural periods during the year: Period “a” – less warm during d-r cycle (IH12d) and for night temperatures (IF3d) and very dry (P3d); Period “b” – intermediate climate between “a” and “c” period for IF3d and IH12d and dry to very dry for P3d (the period “b” can be subdivided into 2 sub-periods: one which starts with the end of the warm and sub-humid period “c”, with a useful water reserve of the soil, and evolves with the fall of the temperatures, and another which starts with the increase of the temperatures and finishes before the sub-humid period “c” returns); Period “c” – the warmest for the IH12d and IF3d, and sub-humid for P3d. The obtained results allow defining the periods “a” and “b”, even with different climatic viticultural potential, as being the most favorable for the production of grapes for wine. The probability of occurrence of the values of the climatic indices (climatic risk or advantages) was characterized at a ten-day level throughout the year. Other index to complement the study will be included, especially the potential water balance of the soil (dryness index – IS). It can be concluded that the concept of the viticultural climate with intra-annual variability of the Géovitivulture MCC System can be used as a zoning element for establishing, in the same vineyard, periods of the year with a higher climatic potential for the production of quality grapes for wine. This climatic criterion will be used in the integrated zoning of the region, especially with the edaphic factors.

DOI:

Publication date: January 12, 2022

Issue: Terroir 2004

Type: Article

Authors

J. Tonietto (1) and A.H. de C. Teixeira (2)

(1) Embrapa – Centre National de Recherche de la Vigne et du Vin – Cnpuv, Rua Livramento, 515 ; 95700-000 – Bento Gonçalves, Brésil
(2) Embrapa – Centre de Recherche du Tropique Semi-Aride – Cpatsa

Contact the author

Keywords

Tropical, intertropical, vin, raisin, qualité, climat avec variabilité intra-annuelle, zonage climatique, Système CCM Géoviticole 

Tags

IVES Conference Series | Terroir 2004

Citation

Related articles…

Adaptation to soil and climate through the choice of plant material

Choosing the rootstock, the scion variety and the training system best suited to the local soil and climate are the key elements for an economically sustainable production of wine. The choice of the rootstock/scion variety best adapted to the characteristics of the soil is essential but, by changing climatic conditions, ongoing climate change disrupts the fine-tuned local equilibrium. Higher temperatures induce shifts in developmental stages, with on the one hand increasing fears of spring frost damages and, on the other hand, ripening during the warmest periods in summer. Expected higher water demand and longer and more frequent drought events are also major concerns. The genetic control of the phenotypes, by genomic information but also by the epigenetic control of gene expression, offers a lot of opportunities for adapting the plant material to the future. For complex traits, genomic selection is also a promising method for predicting phenotypes. However, ecophysiological modelling is necessary to better anticipate the phenotypes in unexplored climatic conditions Genetic approaches applied on parameters of ecophysiological models rather than raw observed data are more than ever the basis for finding, or building, the ideal varieties of the future.

How can historical cultivars mitigate the effects of climate change?

IFV, INRAe and the national network “Partenaires de la Sélection Vigne” representing 37 organizations from the different wine regions, have been working increasingly closely over the last 2 decades towards the preservation of the French varietal patrimony. There are approximately 600 patrimonial varieties according to INRAe and SupAgro Montpellier experts, including ancient cultivars (400) and intravarietal crossbreeds obtained since the 19th century. In the context of a drastic reduction in such varieties from the mid 1980’s in favor of mainstream varieties, it was essential to carry out an inventory of old vines and vineyards. INRAe Vassal collection plays a key role here as it holds the largest diversity available, along with a rich bibliography and herbariums, offering us the opportunity to document and double check the identity of a cultivar, consolidating the expertise of ampelographers. The work is carried out in several stages, from verifying the existence of a variety in a small region, through to rehabilitation. During this session, the authors present the process that leads to the official registration of a variety. After this, IFV selection center takes over to initiate the process of selection and propagation. A specific focus within regions such as the Alps, Champagne and the South-West will provide details of the full procedure. Bia, Bouysselet, Chardonnay rose, Mecle and the aptly named Tardif, are some of the cultivars that have followed this procedure. Furthermore, a recent regulation established by INAO on “varieties of interest for adaptation purposes” might boost uptake by growers. Since 2006, 36 historical cultivars have been registered. Most of these have been neglected in the past due to late maturity, lack of sugar and high titratable acidity at harvest time. Such characteristics are today considered as positive qualities, not only in mitigation of the effects of climate change, but also as an opportunity for restoring diversity…

Photoselective shade films affect grapevine berry secondary metabolism and wine composition

Grapevine physiology and production are challenged by forecasted increases in temperature and water deficits. Within this scenario, photoselective overhead shade films are promising tools in warm viticulture areas to overcome climate change related factors. The aim of this study was to evaluate the vulnerability of ‘Cabernet Sauvignon’ grape berry to solar radiation overexposure and optimize shade film use for berry integrity. A randomized complete block design field study was conducted across two years (2020-2021) in Oakville, Napa Valley, CA, with four shade films (D1, D3, D4, D5) differing in the percent of radiation spectra transmitted and compared to an uncovered control (C0). Integrals for gas exchange parameters and mid-day stem water potential were unaffected by the shade films in 2020 and 2021. By harvest, berries from uncovered and shaded vines did not differ in their size or primary metabolism in either year. Despite precipitation exclusion during the dormant season in the shaded treatments, yield did not differ between them and the control in either season. In 2020, total skin anthocyanins (mg/g fresh mass) in the shaded treatments was greater than C0 during berry ripening and at harvest. Conversely, flavonol concentrations in 2020 were reduced in shaded vines compared to C0. The 2020 growing season highlighted the impact of heat degradation on flavonoids. Flavonoid concentrations in 2021 increased until harvest while flavonoid degradation was apparent from veraison to harvest in 2020 across shaded and control vines. Wine analyses highlighted the importance of light spectra to modify wine composition. Wine color intensity, tonality and anthocyanin values were enhanced in D4 whereas antioxidant properties were enhanced in C0 and D5 wines. Altogether, our results highlighted the need of new approaches in warm viticulture areas given the impact that composition of light has on berry and wine quality.

Permanent cover cropping with reduced tillage increased resiliency of wine grape vineyards to climate change

Majority of California’s vineyards rely on supplemental irrigation to overcome abiotic stressors. In the context of climate change, increases in growing season temperatures and crop evapotranspiration pose a risk to adaptation of viticulture to climate change. Vineyard cover crops may mitigate soil erosion and preserve water resources; but there is a lack of information on how they contribute to vineyard resiliency under tillage systems. The aim of this study was to identify the optimum combination of cover crop sand tillage without adversely affecting productivity while preserving plant water status. Two experiments in two contrasting climatic regions were conducted with two cover crops, including a permanent short stature grass (P. bulbosa hybrid), barley (Hordeum spp), and resident vegetation under till vs. no-till systems in a Ruby Cabernet (V. vinifera spp.) (Fresno) and a Cabernet Sauvingon (Napa) vineyard. Results indicated that permanent grass under no-till preserved plant available water until E-L stage 17. Consequently, net carbon assimilation of the permanent grass under no-till system was enhanced compared to those with barley and resident vegetation. On the other hand, the barley under no-till system reduced grapevine net carbon assimilation during berry ripening that led to lower content of nonstructural carbohydrates in shoots at dormancy. Components of yield and berry composition including flavonoid profile at either site were not adversely affected by factors studied. Switching to a permanent cover crop under a no-till system also provided a 9% and 3% benefit in cultural practices costs in Fresno and Napa, respectively. The results of this work provides fundamental information to growers in preserving resiliency of vineyard systems in hot and warm climate regions under context of climate change.

Effect of multi-level and multi-scale spectral data source on vineyard state assessment

Currently, the main goal of agriculture is to promote the resilience of agricultural systems in a sustainable way through the improvement of use efficiency of farm resources, increasing crop yield and quality under climate change conditions. This last is expected to drastically modify plant growth, with possible negative effects, especially in arid and semi-arid regions of Europe on the viticultural sector. In this context, the monitoring of spatial behavior of grapevine during the growing season represents an opportunity to improve the plant management, winegrowers’ incomes, and to preserve the environmental health, but it has additional costs for the farmer. Nowadays, UAS equipped with a VIS-NIR multispectral camera (blue, green, red, red-edge, and NIR) represents a good and relatively cheap solution to assess plant status spatial information (by means of a limited set of spectral vegetation indices), representing important support in precision agriculture management during the growing season. While differences between UAS-based multispectral imagery and point-based spectroscopy are well discussed in the literature, their impact on plant status estimation by vegetation indices is not completely investigated in depth. The aim of this study was to assess the performance level of UAS-based multispectral (5 bands across 450-800nm spectral region with a spatial resolution of 5cm) imagery, reconstructed high-resolution satellite (Sentinel-2A) multispectral imagery (13 bands across 400-2500 nm with spatial resolution of <2 m) through Convolutional Neural Network (CNN) approach, and point-based field spectroscopy (collecting 600 wavelengths across 400-1000 nm spectral region with a surface footprint of 1-2 cm) in a plant status estimation application, and then, using Bayesian regularization artificial neural network for leaf chlorophyll content (LCC) and plant water status (LWP) prediction. The test site is a Greco vineyard of southern Italy, where detailed and precise records on soil and atmosphere systems, in-vivo plant monitoring of eco-physiological parameters have been conducted.