GiESCO 2019 banner
IVES 9 IVES Conference Series 9 GiESCO 9 GiESCO 2019 9 Climate change 9 The temperature‐based grapevine sugar ripeness (GSR) model for adapting a wide range of Vitis vinifera L. cultivars in a changing climate

The temperature‐based grapevine sugar ripeness (GSR) model for adapting a wide range of Vitis vinifera L. cultivars in a changing climate

Abstract

Context and purpose of the study ‐ Temperatures are increasing due to climate change leading to advances in grapevine phenology and sugar accumulation in grape berries. This study aims (i) to develop a temperature‐based model that can predict a range of target sugar concentrations for various cultivars of Vitis vinifera L and (ii) develop extensive classifications for the sugar ripeness of cultivars using the model.

Material and methods ‐ Time series of sugar concentrations were collected from research institutes, extension services and private companies from various European countries. The Day of the Year (DOY) to reach the specified target sugar concentration (170, 180, 190, 200, 210, and 220 g/l) was determined and a range of models tested using these DOYs to develop the best fit model for Vitis vinifera L.

Results ‐ The best fit linear model– Growing Degree Days (parameters: base temperature (t0) = 0°C, start date (Tb) = 91 or 1 April), Northern Hemisphere) – represented the model that required the least parameters and therefore the simplest in application. The model was used to characterise and classify a wide range of cultivars for DOY to reach target sugar concentrations.
The model is referred to as the Grapevine Sugar Ripeness Model (GSR). It is viticulturist‐ friendly as it’s simple in form (linear) and its growing degree day units are easily calculated by adding average temperatures (base temperature was optimized at 0°C) derived from weather stations from the 91th day of the year (Northern Hemisphere). The classifications based on this model can inform cultivar choice as an alternative adaptation strategy to climate change, where changing cultivars may prevent the harvesting of grapes at high sugar concentrations which leads to higher alcohol wines.

DOI:

Publication date: June 19, 2020

Issue: GiESCO 2019

Type: Article

Authors

Amber K. PARKER (1), Inaki GARCÍA DE CORTÁZAR‐ATAURI (2), Laurence GÉNY (3), Jean‐Laurent SPRING (4), Agnès DESTRAC (5), Hans SCHULTZ (6), Manfred STOLL (6), Daniel MOLITOR (7), Thierry LACOMBE (8), Antonio GRACA (9), Christine MONAMY (10), Paolo STORCHI (11), Mike TROUGHT (12), Rainer HOFMANN (1), Cornelis VAN LEEUWEN (5)

(1) Department of Wine, Food and Molecular Biosciences, Faculty of Agriculture and Life Sciences, PO Box 85084, Lincoln University, Lincoln 7647, Christchurch, New Zealand
(2) Institut National de la Recherche Agronomique (INRA), US 1116 AGROCLIM, F-84914 Avignon, France
(3) Institut des Sciences de la Vigne et du Vin, Université de Bordeaux, Unité de Recherche Oenologie EA 4577 – USC 1366 INRA, 210 chemin de Leysotte – CS 50008, 33882 Villenave d’Ornon cedex
(4) Agroscope, Av. de Rochettaz 21,1009 Pully, Switzerland
(5) EGFV, Bordeaux Sciences Agro, INRA, Univ. Bordeaux, ISVV, 33883 Villenave d’Ornon, France
(6) Hochschule, Giesenheim University, Von-Lade-Straße 1, D-65366 Geisenheim
(7) Luxembourg Institute of Science and Technology (LIST), Environmental Research and Innovation (ERIN) Department 41, rue du Brill, L-4422 Belva, Luxembourg
(8) Institut National de la Recherche Agronomique (INRA), AGAP, Univ Montpellier, CIRAD, INRA, Montpellier SupAgro, 2 place Viala, F-34060 Montpellier, France
(9) Sogrape Vinhos S.A., R. 5 de Outubro 558, 4430-809 Avintes, Portugal
(10) Bureau Interprofessionnel des Vins de Bourgogne – BIVB, 12 boulevard Bretonnière, 21200, Beaune, France
(11) CREA – Centro di ricerca Viticoltura ed Enologia, Viale Santa Margherita 80 52100 – Arezzo, Italy 12The New Zealand Institute for Plant and Food Research Limited, Blenheim 7240, New Zealand, Department of Wine, Food and Molecular Biosciences, Faculty of Agriculture and Life Sciences, PO Box 85084, Lincoln University, Lincoln 7647, Christchurch, New Zealand

Contact the author

Keywords

modelling, temperature, sugar, cultivars, climate change

Tags

GiESCO 2019 | IVES Conference Series

Citation

Related articles…

Impact of yeast derivatives to increase the phenolic maturity and aroma intensity of wine

Using viticultural and enological techniques to increase aromatics in white wine is a prized yet challenging technique for commercial wine producers. Equally difficult are challenges encountered in hastening phenolic maturity and thereby increasing color intensity in red wines. The ability to alter organoleptic and visual properties of wines plays a decisive role in vintages in which grapes are not able to reach full maturity, which is seen increasingly more often as a result of climate change. A new, yeast-based product on the viticultural market may give the opportunity to increase sensory properties of finished wines. Manufacturer packaging claims these yeast derivatives intensify wine aromas of white grape varieties, as well as improve phenolic ripeness of red varieties, but the effects of this application have been little researched until now. The current study applied the yeast derivative, according to the manufacture’s instructions, to the leaves of both neutral and aromatic white wine varieties, as well as on structured red wine varieties. Chemical parameters and volatile aromatics were analyzed in grape musts and finished wines, and all wines were subjected to sensory analysis by a tasting panel. Collective results of all analyses showed that the application of the yeast derivative in the vineyard showed no effect across all varieties examined, and did not intensify white wine aromatics, nor improve phenolic ripeness and color intensity in red wine.

Biodiversity in the vineyard agroecosystem: exploring systemic approaches

Biodiversity conservation and restoration are essential for guarantee the provision of ecosystem services associated to vineyard agroecosystem such as climate regulation trough carbon sequestration and control of pests and diseases. Most of published research dealing with the complexity of the vineyard agroecosystems emphasizes the necessity of innovative approaches, including the integration of information at different temporal and spatial scales and development of systemic analysis based on modelling. A biodiversity survey was conducted in the Franciacorta wine-growing area (Lombardy, Italy), one of the most important Italian wine-growing regions for sparkling wine production, considering a portion of the territory of 112 ha. The area was divided into several Environmental Units (EUs), defined as a whole vineyard or portion of vineyard homogenous in terms of four agronomic characteristics: planting year, planting density, cultivar, and training system. In each EU a set of compartments was identified and characterised by specific variables. The compartments are meteorology, morphology (altitude, slope, aspect, row orientation, and solar irradiance), ecological infrastructures and management. The landscape surrounding EU was also characterised in terms of land-use in a buffer zone of 500 m. For each component a specific methodology was identified and applied. Different statistical approaches were used to evaluate the method to integrate the information related to different compartments within the EU and related to the buffer zone. These approaches were also preliminarily evaluated for their ability to describe the contribution of biodiversity and landscape components to ecosystem services. This methodological exploration provides useful indication for the development of a fully systemic approach to structural and functional biodiversity in vineyard agroecosystems, contributing to promote a multifunctional perspective for the all wine-growing sector.

Mapping and tracking canopy size with VitiCanopy

Understanding vineyard variability to target management strategies, apply inputs efficiently and deliver consistent grape quality to the winery is essential. However, despite inherent vineyard variability, the majority are managed as if they are uniform. VitiCanopy is a simple, grower-friendly tool for precision/digital viticulture that allows users to collect and interpret objective spatial information about vineyard performance. After four years of field and market research, an upgraded VitiCanopy has been created to achieve a more streamlined, technology-assisted vine monitoring tool that provides users with a set of superior new features, which could significantly improve the way users monitor their grapevines. These new features include:
• New user interface
• User authentication
• Batch analysis of multiple images
• Ease the learning curve through enhanced help features
• Reporting via the creation of colour maps that will allow users to assess the spatial differences in canopies within a vineyard.
Use-case examples are presented to demonstrate the quantification and mapping of vineyard variability through objective canopy measurements, ground-truthing of remotely sensed measurements, monitoring of crop conditions, implementation of disease and water management decisions as well as creating a history of each site to forecast quality. This intelligent tool allows users to manage grapevines and make informed management choices to achieve the desired production targets and remain profitable.

What are the optimal ranges and thresholds for berry solar radiation for flavonoid biosynthesis?

In wine grape production, canopy management practices are applied to control the source-sink balance and improve the cluster microclimate to enhance berry composition. The aim of this study was to identify the optimal ranges of berry solar radiation exposure (exposure) for upregulation of flavonoid biosynthesis and thresholds for their degradation, to evaluate how canopy management practices such as leaf removal, shoot thinning, and a combination of both affect the grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) yield components, berry composition, and flavonoid profile under context of climate change. First experiment assessed changes in the grape flavonoid content driven by four degrees of exposure. In the second experiment, individual grape berries subjected to different exposures were collected from two cultivars (Cabernet Sauvignon and Petit Verdot). The third experiment consisted of an experiment with three canopy management treatments (i) LR (removal of 5 to 6 basal leaves), (ii) ST (thinned to 24 shoots per vine), and (iii) LRST (a combination of LR and ST) and an untreated control (UNT). Berry composition, flavonoid content and profiles, and 3-isobutyl 2-methoxypyrazine were monitored during berry ripening. Although increasing canopy porosity through canopy management practices can be helpful for other purposes, this may not be the case of flavonoid compounds when a certain proportion of kaempferol was achieved. Our results revealed different sensitivities to degradation within the flavonoid groups, flavonols being the only monitored group that was upregulated by solar radiation. Within different canopy management practices, the main effects were due to the ST. Under environmental conditions given in this trial, ST and LRST hastened fruit maturity; however, a clear improvement of the flavonoid compounds (i.e., greater anthocyanin) was not observed at harvest. Methoxypyrazine berry content decreased with canopy management practices studied. Although some berry traits were improved (i.e. 2.5° Brix increase in berry total soluble solids) due to canopy management practices (ST), this resulted in a four-fold increase in labor operations cost, two-fold decrease in yield with a 10-fold increase in anthocyanin production cost per hectare that should be assessed together as the climate continues to get hot.

Deconstructing the soil component of terroir: from controversy to consensus

Wine terroir describes the collectively recognized relation between a geographical area and the distinctive organoleptic characteristics of the wines produced in it. The overriding objective in terroir studies is therefore to provide scientific proof relating the properties of terroir components to wine quality and typicity. In scientific circles, the role of climate (macro-, meso- and micro-) on grape and wine characteristics is well documented and accepted as the most critical. Moreover, there has been increasing interest in recent years about new elements with possible importance in shaping wine terroir like berry/leaf/soil microbiology or even aromatic plants in proximity to the vineyard conferring flavors to the grapes. However, the actual effect of these factors is also dependent on complex interactions with plant material (variety/clone, rootstock, vine age) and with human factors.
The contribution of soil, although a fundamental component of terroir and extremely popular among wine enthusiasts, remains a much-debated issue among researchers. The role of geology is probably the one mostly associated by consumers with the notion of terroir with different parent rocks considered to give birth to different wine styles. However, the relationship between wine properties and the underlying parent material raises a lot of controversy especially regarding the actual existence of rock-derived flavors in the wine (e.g. minerality). As far as the actual soil properties are concerned, the effect of soil physical properties is generally regarded as the most significant (e.g sandy soils being associated with lighter wines while those on clay with colored and tannic ones) mostly through control of water availability which ultimately modifies berry ripening conditions either directly by triggering biosynthetic pathways, or indirectly by altering vigor and yield components. The role of soil chemistry seems to be weakly associated to wine sensory characteristic, although N, K, S and Ca, but also soil pH, are often considered important in the overall soil effect.
Recently, in the light of evidence provided by precision agriculture studies reporting a high variability of vineyard soils, the spatial scale should also be taken into consideration in the evaluation of the soil effects on wines. While it is accepted that soil effects become more significant than climate on a local level, it is not clear whether these micro-variations of vineyard soils are determining in the terroir effect. Moreover, as terroir is not a set of only natural factors, the magnitude of the contribution of human-related factors (irrigation, fertilization, soil management) to the soil effect still remains ambiguous. Lastly, a major shortcoming of the majority of works about soil effects on wine characteristics is the absence of connection with actual vine physiological processes since all soil effects on grape and wine chemistry and sensorial properties are ultimately mediated through vine responses.
This article attempts to breakdown the main soil attributes involved in the terroir effect to suggest an improved understanding about soil’s true contribution to wine sensory characteristics. It is proposed that soil parameters per se are not as significant determining factors in the terroir effect but rather their mutual interactions as well as with other natural and human factors included in the terroir concept. Consequently, similarly to bioclimatic indices, composite soil indices (i.e. soil depth, water holding capacity, fertility, temperature etc), incorporating multiple soil parameters, might provide a more accurate and quantifiable means to assess the relative weight of the soil component in the terroir effect.