Papers by Cornelis van Leeuwen
HAL (Le Centre pour la Communication Scientifique Directe), Mar 29, 2023
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
IVES technical reviews, Oct 28, 2020
How to measure and manage the soil effect in terroir expression >>> Terroir relates the taste of ... more How to measure and manage the soil effect in terroir expression >>> Terroir relates the taste of wine to the place where it was produced. It involves the influence of climate, soil, cultivar and viticultural practices on wine. A lot of progress has been made over the years in understanding how soil can shape the quality and style of a wine. To observe and explain the soil effect, it needs to be broken into measurable factors. Once these are quantified by appropriate approaches, a terroir can be mapped and managed. By fine-tuning the choice of plant material (rootstock and variety) and viticultural techniques according to local soil conditions, it is possible to optimise terroir expression. <<<
HAL (Le Centre pour la Communication Scientifique Directe), Jan 14, 2016
Il y a aujourd'hui un consensus de la communauté scientifique sur la réalité du changement climat... more Il y a aujourd'hui un consensus de la communauté scientifique sur la réalité du changement climatique. Celui-ci se manifeste principalement par une augmentation des températures. Le phénomène est observé sur l'ensemble du globe, même si l'amplitude de l'augmentation des températures présente des différences régionales majeures. Les climatologues prévoient une continuation de cette évolution, mais avec des différences marquées en fonction des scenarii des émissions de gaz à effet de serre, avec de 1 à 4°C supplémentaires d'ici la fin du siècle. Il est plus difficile de prévoir une tendance pour les précipitations. Les modifications des régimes de pluie connaîtront probablement des différences régionales et saisonnières marquées. Il est probable que des phénomènes extrêmes, comme des épisodes de précipitations diluviennes, deviendront plus fréquentes. La sécheresse perçue par les cultures dépend à la fois des précipitations et de l'Evapo Transpiration Potentielle (ETP). Comme l'ETP augmente mécaniquement avec la température, la durée et l'intensité des périodes de sécheresse sera accrue, même en l'absence d'une diminution des précipitations. Le changement climatique s'accompagne enfin d'une augmentation du rayonnement, en particulier dans les longueurs d'onde correspondant aux UV-B.
HAL (Le Centre pour la Communication Scientifique Directe), Dec 11, 2008
Le matériel végétal est un élément majeur de la notion de terroir. Les Vitacées comptent plus de ... more Le matériel végétal est un élément majeur de la notion de terroir. Les Vitacées comptent plus de 1 000 espèces dont la plus cultivée, Vitis vinifera, possède plus de 6 000 variétés. Depuis 40 ans, la sélection de la vigne s'est opérée de manière à produire des clones pour les principaux cépages. Seulement 300 d'entre eux possèdent au moins un clone. Une douzaine de variétés sont très répandues et considérées comme internationales. L'extrême rigueur sanitaire qui accompagne la sélection clonale a conduit à éliminer la majorité des plants jugés performants mais porteurs de virus ou phytoplasme. L'évolution climatique va modifier les conditions environnementales des terroirs, le comportement des cépages en un lieu donné et donc le profil des vins produits. Il est donc essentiel de pouvoir à l'avenir sélectionner de nouveaux clones mieux adaptés à ces nouvelles conditions de production. La préservation de la biodiversité passe par la mise en oeuvre d'une sélection massale performante. Si la filière vitivinicole ne prend pas de mesures pour la mettre en oeuvre rapidement, il ne restera plus que l'hybridation ou l'obtention d'OGM comme voie de sélection à l'avenir. Il est urgent de préserver les parcelles de plus de 40 ans, de sélectionner les plants performants de ces parcelles et de ne les complanter qu'avec leur propre matériel végétal sélectionné. La sélection massale nécessite une prise en compte individuelle sur chaque propriété et un investissement de la filière en terme d'aide technique et financière.
HAL (Le Centre pour la Communication Scientifique Directe), Dec 11, 2008
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Sep 17, 2020
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
HAL (Le Centre pour la Communication Scientifique Directe), Dec 8, 2011
HAL (Le Centre pour la Communication Scientifique Directe), Jul 17, 2022
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
OENO One, Jun 24, 2022
Nitrogen (N) is an essential element for vine development and yield; it is also involved in the w... more Nitrogen (N) is an essential element for vine development and yield; it is also involved in the winemaking process and significantly affects wine composition. It is therefore essential to control and optimise plant N use to ensure an adequate N composition of the grapes at harvest. An improved understanding of the impact of cultivation practices on plant N metabolism would allow a better orientation of technical choices with the objective of quality and sustainability (i.e., fewer inputs, more efficiency). Our trial focused on the impacts of fertilisation and crop thinning on grape N composition. A wide crop load gradient was set up in a homogeneous plot of Chasselas (Vitis vinifera L.) in an experimental vineyard in Switzerland. Foliar urea was applied at veraison in order to compare it with an unfertilised control. Vine development and grape composition were evaluated over two years, with particular attention to the carryover effects of both fertilisation and crop thinning. Foliar N fertilisation effectively increased the amount of N in grapes at harvest in the same year, but had no impact on grape ripeness or carryover effect on year n + 1. Conversely, crop thinning improved grape maturity by reducing fruit N and C demand. Interestingly, amino N proportions could be distinguished according to crop load, while the global grape N concentration at harvest remained unchanged. Some amino acids were more affected by crop thinning than others. The concentrations of alanine, γ-aminobutyric acid (GABA), serine and threonine were reduced by crop thinning. Crop thinning had a strong carryover effect on year n + 1. The carryover impact of crop thinning on grapes in terms of both maturation index and N composition could be observed at the onset of grape ripening on year n + 1. This experiment highlighted the influence of the previous year's agricultural practices on grape C and N accumulation before and during the ripening phase. Consequently, the modulation of grape composition at harvest should be considered over two consecutive years. These results will contribute to the improvement of predictive models and sustainable agronomic practices in perennial crops.
OENO One, Dec 31, 2005
This paper deals with the technical and/or practical treatment of terroir as a study concept, tog... more This paper deals with the technical and/or practical treatment of terroir as a study concept, together with related functional aspects. Functioning of the terroir relies on the relation between climate, soil and vine. In addition to this interaction, a comprehensive study concept for terroir requires the consideration of viticultural and enological sciences and techniques necessary to ensure the assurance of wine quality, together with spatial aspects of the grapevine response to environmental factors, as required for vineyard management. In order to comprehend the quality of the harvest, it is necessary to understand the relationship « whole plant -berry ». An easy field and laboratory method to study the relationship between the whole plant and berry and the consequences thereof for wine quality is proposed. Knowledge of grapevine water status and the biochemical evolution within the grape berry from berry set onwards are important issues for the understanding of the role that terroir plays with respect to the quality of the harvest and the wine style or « typicality ». Résumé : Le terroir est un concept qui nécessite une approche globale permettant une étude combinée du climat, du sol, de la vigne et du rôle de l'homme. Les sciences de la viticulture et de l'oenologie sont alors nécessaires pour comprendre les déterminants de la qualité du vin en relation avec les facteurs de l'environnement. En connexion aux études de terroir qui portent sur le climat et le sol, nous proposons une approche globale qui intègre l'étude des relations «vigne -raisin -vin ». L'état hydrique de la vigne est l'un des éléments clefs du fonctionnement de la vigne et de la qualité du raisin en relation avec le style de vin. Cet article rappelle les méthodes de référence pour la mesure de l'état hydrique de la vigne et les conséquences possibles des déficits hydriques sur le fonctionnement de la plante et de ses fruits.
HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific r... more HAL is a multi-disciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
OENO One
Measurement of carbon isotope discrimination in berry juice at maturity (δ13C) provides an integr... more Measurement of carbon isotope discrimination in berry juice at maturity (δ13C) provides an integrated assessment of vine water status and water use efficiency (WUE) during the period of berry ripening, and when collected over multiple seasons, can provide an indication of drought stress responses. Berry juice δ13C measurements were carried out on 48 different varieties planted in a common garden experiment in Bordeaux, France from 2014 through 2020 and found important differences across this large panel of varieties. Cluster analysis showed that δ13C values are likely affected by the differing phenology of each variety, resulting in berry ripening of different varieties taking place under different conditions of soil water availability within the same year. Accounting for these phenological differences, the cluster analysis created a classification of varieties that corresponds well to our current empirical understanding of their relative drought tolerance. In addition, using measur...
Grape rootstocks were first developed to address the phylloxera crisis during the late 1800s, and... more Grape rootstocks were first developed to address the phylloxera crisis during the late 1800s, and many of these rootstocks continue to be used. However, changes in the climate, water availability, pest pressure, and pest control practices require the development of new and better adapted rootstocks. Many of the traits we need to address these issues are from Vitis species that have not been widely used in the past, either because they rooted poorly or had marginal phylloxera resistance.
HAL (Le Centre pour la Communication Scientifique Directe), Dec 31, 2022
Functional Plant Biology, 2020
Nitrogen deficit affects both crop production and composition, particularly in crops requiring an... more Nitrogen deficit affects both crop production and composition, particularly in crops requiring an optimal fruit N content for aroma development. The adaptation of cultural practices to improve N use efficiency (NUE) (i.e. N uptake, assimilation and partitioning) is a priority for the sustainable production of high-quality crops. A trial was set on potted grapevines (Vitis vinifera L. cv. Chasselas) to investigate the potential of crop limitation (via bunch thinning) to control plant NUE and ultimately fruit N composition at harvest. A large crop load gradient was imposed by bunch thinning (0.5–2.5 kg m–2) and N traceability in the plant was realised with an isotope-labelling method (10 atom % 15N foliar urea). The results indicate that the mobilisation of root reserves plays a major role in the balance of fruit N content. Fertiliser N uptake and assimilation appeared to be strongly stimulated by high-yielding conditions. Fertilisation largely contributed to fulfilling the high fruit...
Adaptation to climate change : which are the main challenges for the French wine industry?. 36. S... more Adaptation to climate change : which are the main challenges for the French wine industry?. 36. South African Conference on Enology and Viticulture
Climate is a key variable for grapevine development and berry ripening processes. At mesoscale le... more Climate is a key variable for grapevine development and berry ripening processes. At mesoscale level, climate spatial variations are often determined empirically, as weather station networks are generally not dense enough to account for local climate variations. In this study, climate spatial variations of Bordeaux winegrowing area were assessed by means of solar radiation cartography using satellite sensing and Digital Elevation Model (DEM) information, daily temperature interpolation using weather station and terrain information, spatialized rainfall using rain gauge data and kriging techniques. Temperature and solar radiation data were used to generate evapotranspiration maps at daily time step. Spatialized data was used to characterize the production potential of several zones of Bordeaux winegrowing areas, according to their agroclimatic characteristics. Temperature differences within Bordeaux vineyards induce considerable discrepancies in vine phenology, as is shown by means of a degree.day model. Solar radiation data and potential evapotranspiration are mostly governed by terrain characteristics (slope and aspect). Rainfall data spatial patterns indicate that the northwestern part of Bordeaux vineyards is recurrently drier and the southwestern receives higher rainfall amounts during the grapevine growing season. However, spatial distribution of summer rainfall events changes considerably from one year to another. The results of this study offer useful information to adapt grapevine cultivars and vineyard management to local climate.
American Journal of Enology and Viticulture, 2011
Berry fresh weight and composition are under the control of complex interactions among genotype, ... more Berry fresh weight and composition are under the control of complex interactions among genotype, environmental factors, and viticulture practice, which all affect not only the mean value but also the ranges of variation in berry traits. Both mean values and variation range in berry composition play a role in berry quality and, subsequently, wine typicity. This review examines recent ecophysiological, genetic, and molecular knowledge to provide better understanding of the mechanisms that influence variability in berry weight and composition. We specifically reviewed the variation range in berry weight and composition (including sugars, organic acids, and anthocyanins) among Vitis genotypes, the environmental and viticulture practices that cause variability for a given cultivar, the genetic clues underlying the genotypic variation, and the putative genes controlling berry weight and composition. Despite numerous studies comparing differences in the mean value of a berry trait among different environment conditions and viticulture practices, very few studies have explored the level of variation in response to those factors. Present genetic and molecular studies are mainly focused on identifying genes involved in the control of berry weight and composition, with few considerations of environmental factors that affect their expression. In the future, more effort should be directed toward integration of genetic and molecular work with ecophysiological approaches in an effort to gain novel insights into the cause of variability in grape fresh weight and composition.
Australian Journal of Grape and Wine Research, 2011
Background and Aims: Phenological models, which are based on responses of the plant to temperatur... more Background and Aims: Phenological models, which are based on responses of the plant to temperature, are useful tools to predict grapevine (Vitis vinifera L.) phenology in various climate conditions. This study aimed to develop a single process-based phenological model at the species level to predict two important stages of development for V. vinifera L.: flowering and veraison. Methods and Results: Three different phenological models were tested and the model that gave the best results was optimised for its parameters. The chosen model Spring Warming was found optimal with regard to the trade-off between parsimony of input parameters and efficiency. The base temperature (Tb) of 0°C calculated from the 60th day (t0) of the year (for the Northern hemisphere) was found to be the most optimal parameter set tested. This model henceforth referred to as the Grapevine Flowering Veraison model (GFV) was successfully validated at the varietal level using an independent dataset. Conclusions: A general phenological model, GFV, has been successfully developed to characterise the timing of flowering and veraison for the grapevine. Significance of the Study: The model is simple for the user, can be successfully applied to many varieties and can be used as an easy predictor of phenology for different varieties under climate change scenarios.
IVES Technical Reviews, vine and wine
Harvesting grapes at the appropriate maturity is key to the production of high quality red wines.... more Harvesting grapes at the appropriate maturity is key to the production of high quality red wines. Viticulturists, oenologists and winemakers define several types of maturity: technological, phenolic and aromatic. Aromatic maturity is probably the most important for determining wine quality and typicity, including terroir expression. This article (part II) reviews the influence of terroir factors and management practices on aromatic maturity; the latest knowledge regarding compounds that underpin aromatic maturity was addressed in a previous article (Part I).
Uploads
Papers by Cornelis van Leeuwen