Thierry Dufourcq

L’Institut Français de la Vigne et du Vin | IFV · Pôle Sud-Ouest

Nowadays the rapidly increasing organic vineyard management with the utilization of copper as sole fungal control pesticide against downy mildew raises once again the question of copper impact on varietal thiols in wine. For this purpose, Colombard and Gros Manseng grape juices were fermented under different copper levels (from 0.2 to 3.88 mg/l) to...

As elsewhere, southwestern France vineyards face more recurrent summer heat waves these last years. Among the possibilities of adaptation to this climate changing parameter, the use of net shading is a technique that allows for limiting canopy exposure to radiations. In this trial, we tested net shading installed on one face of the canopy, on a nor...

The gradual change in rainfall patterns experienced in the south of France vineyards, especially around the Mediterranean Sea, means that the vines are increasingly subject to summer drought. The winegrowers developed the use of irrigation techniques to ensure the maintenance of competitive yields in the production of wines under Protected Geograph...

The development of fertigation could be a possible solution to adapt PGI Côtes de Gascogne (south-western France) wine production to climate change. The goal would be to limit the negative effects of water stress on yield performance expectation (around 15 tons per hectare) and to make the use of fertilizers more efficient. This study aimed to comp...

Background and Aims The thiol aromatic potential of the grape cultivars, Colombard and Gros Manseng, from Côtes de Gascogne was characterised for the first time. Methods and Results We demonstrated that both cultivars contained a concentration of glutathionylated and cysteinylated precursors of 3-sulfanylhexan-1-ol up to 454 and 21 μg/kg, respecti...

The aim of this study was to evaluate the role played by climatic conditions during grape ripening in the protein instability of white wines produced in the French southwest region. For this purpose, basic wine analyses were carried out on 268 musts and the corresponding wines, all produced during the 2016, 2017, 2018, and 2019 vintages, with disti...

Vitiforest is an exploratory project. The objectives were to assess and describe the effects of trees on the agronomic behavior of the vine, on the microclimate, as well as on the aerial and soil biodiversity. The technical and economic aspects were also assessed. A multidisciplinary team of researchers set up various protocols and measurement tool...

Aim: Rotundone and 3-isobutyl-2-methoxypyrazine (IBMP) are two potent aroma compounds responsible for pepper and bell pepper notes in red wines, respectively. The aim of the study was to modulate, through common viticultural practices, the volatile composition in these two molecules of Fer red wines from a temperate climate wine region with very co...

Aim: Rotundone and 3-isobutyl-2-methoxypyrazine (IBMP) are two potent aroma compounds responsible for pepper and bell pepper notes in red wines, respectively. The aim of the study was to modulate, through common viticultural practices, the volatile composition in these two molecules of Fer red wines from a temperate climate wine region with very co...

Phenology is concerned with the periodic phenomenon of the vine growing cycle (bud burst, flowering, veraison (color change), in relation to the climate. It is a veritable biological clock of the vines. The timing of the numerous operations in the vineyard (phytosanitary protection, defoliation, crop thinning….) is undertaken in accordance with the...

Aim: A study was carried out in 2013 and 2014 to determine the key environmental and viticultural variables affecting the concentration of rotundone, the black pepper aroma compound, in Vitis vinifera L. cv. Duras red wines at 10 different vineyard blocks. Methods and Results: For each block, data for fruit quality attributes, as well as climatic a...

Today winegrowers involved in mechanical winter pruning are applying this viticultural technique on two main training systems, the free cordon, appearing to be the more efficient, and the trellised vertical shoot positioning (VSP) system. The main reasons for maintaining the trellis are generally due to common habits in vineyard management, risk of...

Temperature is a key environmental factor affecting grape primary and secondary metabolites. Even if several mesoscale studies have already been conducted on temperature especially within a Protected Designation of Origin area, few data are available at an intra-block scale. The present study aimed at i) assessing the variability in bunch zone air...

In a context of reducing the environmental footprint of the wine sector, the European project WETWINE (2016-2019) aims to validate an innovative natural-based technology for winery wastewater treatment. The WETWINE valorisation system associates an anaerobic pre-treatment unit with a combination of subsurface flow constructed wetlands. A circular e...

Winter pruning is today the longest operation for hand workers in the vineyard. Over the last years, mechanical pruning practices have become popular in southern France vineyards to respond to competitiveness issue especially for the basic and mid-range wine production. Wine farmers have developed different vineyard management techniques associated...

Ce numéro est constitué d’articles de synthèse des projets DEPHY EXPE publiés à l’occasion du Colloque National DEPHY EXPE, qui s’est déroulé le 28 mai 2019 à l'Assemblée Permanente des Chambres d'Agriculture (Paris).

In 2015 and 2016, a field trial was carried out to determine the effect of three viticultural practices (leaf removal 10 days after berry set, removal of lateral shoots and delayed harvest 7 days after the control) on 2-methoxy-3-isobutylpyrazine (IBMP) and rotundone in Fer wines from a cool climate region located in the South West of France. Among...

Sustainability of agricultural production systems is nowadays considered as a major challenge to face. Viticulture is particularly affected by environmental issues, especially because of its consumption in pesticides. Besides, the social demand in environment-friendly products is increasing, and the reputation of wines produced under Protected Deno...

The main objectives of this study was to decrease wine alcohol content by combining several techniques, from the vineyard to the cellar. The combination of these techniques should allow to decrease alcohol in wine by 2% in volume. A two years trial was focused on two main cultivars of the southwest of France vineyard: Tannat N and Gros Manseng B. B...

Sustainability of agricultural production systems is nowadays considered as a major challenge to face. Viticulture is particularly affected by environmental issues, especially because of its consumption in pesticides. Besides, the social demand in environment-friendly products is increasing, and the reputation of wines produced under Protected Deno...

Prod 2018-253f EA BIOmE INRA

This study seeks to assess viticultural factors having an effect on the dimethyl sulfide precursor concentration in grapes of Vitis vinifera L. cv. Malbec N. This odorless precursor, remaining in young wines after fermentation, releases dimethyl sulfide in wine during aging and contributes to a reductive and complex aromatic bouquet, with reminisce...

Planting intercropped trees with grapevines is a practice that have recently been developed in French vineyards in order to bring beneficial effects to the parcel and its environment. The expected positive effect are an improvement in aerial and soil biodiversity and mitigation of climate extremes like wind or temperature. The competition for resou...

Avec près de 600 000 hl, le vignoble des Côtes de Gascogne est la première région française sous indication géographique protégée (IGP) pour la production de vins blancs. La région a bâti sa réputation et son succès commercial sur le marché intérieur et à l’international autour de ses vins blancs frais, fruités surexprimant le caractère thiolé. L’e...

Intecroping trees within vineyards modify the microclimate and potentially the grapevine responses to water stress through three mechanisms: shading, wind breaking and evapotranspiration. In this context, we investigate the impacts of agroforestry on grapevine water status and the potential consequences on grapevine performances. Different types of...

Des travaux récents ont mis en avant une importante variabilité de concentration en rotundone - le principal composé responsable de l'arôme poivré des vins rouges - au sein d'une même parcelle, en lien avec les caractéristiques du sol et le niveau de contrainte hydrique. Afin de développer une méthode pour cartographier de manière indirecte et simp...

Between 2005 and 2011, the impact of foliar application of nitrogen alone or with sulfur on grape and wine characteristics was assessed on six French grape varieties (Sauvignon Blanc, Colombard, Gros Manseng, Négrette, Fer and Melon) grown in the south-west of France and the Loire Valley, and on Carignan in northern Spain. Nitrogen applications wer...

Aim: Few recent studies have been investigating the effect of clone on aroma compounds. The aim of this research work was to study the impact of certified clones from Vitis vinifera L. cv. Duras N on grape quality and rotundone, a sesquiterpene responsible for peppery aroma which has been reported recently in red wines made from this cultivar. Meth...

Recent research works highlighted large variability in rotundone concentration - the main compound responsible for peppery aroma in red wines - within a vineyard block associated with variation in land underlying the vineyard and vine water deficit. In order to further study and determine practical ways to map rotundone spatial variability, a study...

Environmental benefits of permanent cover crop in vineyard are well known. Nevertheless, permanent cover cropping is quite rare in French Mediterranean vineyards, because there is a risk of severe drought during summer, and consequently yield losses. Over the past few years, irrigation has developed in this area, offering new possibilities for bett...

In the framework of a French network of researchers working on the phenology of forest trees, fruit trees and grapevine (PERPHECLIM ACCAF project), methods of observations and sampling strategies were discussed and compared. The objective was a harmonisation of data acquisition strategies for grapevine phenology. The BBCH scale was chosen as a refe...

Ce travail s'inscrit dans une approche d'adaptation de la viticulture locale aux évolutions du climat dans un objectif de maintien de la caractéristique aromatique typique des vins produits sur la zone. La maitrise de l'expression variétale d'un vin blanc est dans ce cas un enjeu essentiel pour son accès au marché. Le vignoble des Côtes de Gascogne...

Background and AimsRotundone, a potent aroma compound responsible for peppery aroma and flavour in Shiraz, was detected recently in Vitis vinifera L. cv. Duras wines. In 2011 and 2012, two separate experiments were carried out to determine the effect of ripeness and viticultural techniques on rotundone concentration in Duras wine.Methods and Result...

Résumé : L’extraction des jus au cours du pressurage est une étape déterminante dans la production de vins blancs aromatiques. Les pressoirs pneumatiques classiques peuvent être une porte d’entrée aux phénomènes oxydatifs, notamment au cours du rebêchage. Les auteurs testent ici un système d’injection fractionnée d’anhydride sulfureux directement a...

Les premiers travaux scientifiques répertoriés sur le traitement thermique de la vendange ont été conduits en laboratoire et de manière artisanale il y a plus de 60 ans en Californie (Berg 1950). Dans les années soixante-dix, le développement de systèmes industriels de chauffage et le nombre important d’articles scientifiques sur le sujet (Poux 197...

L’un des volets du projet VINAROMAS a permis de caractériser finement cinq itinéraires de macération en rouge. Certaines de ces techniques, comme la macération préfermentaire à chaud ou la macération carbonique par exemple, ont fait l’objet d’études il y a de nombreuses années. Ces recherches s’étaient alors orientées plus sur l’optimisation du pot...

RÉSUMÉ Le modèle WaLIS (WAter baLance for Intercropped Systems) est un modèle de bilan hydrique qui simule l'évolution de la teneur en eau du sol au pas de temps journalier. Il est adapté pour tenir compte, en viticulture, de la compétition vis-à vis de l'eau due à la présence d'un enherbement sur la parcelle. Il existe une relation entre la fract...

Proceedings 18th International Symposium of the GiESCO, Porto, 7-11 juillet 2013

Depuis 2004, l’IFV Sud-Ouest étudie l’intérêt de pulvérisations foliaires d’azote réalisées à la véraison afin d’améliorer le fruité des vins issus de cépages dont le potentiel aromatique s’exprime par la présence de thiols variétaux comme le Colombard ou le Sauvignon. La technique, qui a fait l’objet de nombreuses communications ces dernières anné...

The aim of this study was to use the dimethyl-sulfide (DMS), a volatile reminiscent of truffle, as an indicator of the aging potential of Malbec wines from the French Cahors "Appellation d'Origine". This sulfur compound appears slowly during wine aging. Furthermore, it is now possible to estimate the DMS potential release (PDMS) in grapes or young...

In order to reduce the use of herbicides, total grass cover (between and under the rows of vine) could be an interesting solution if the competition for nitrogen and water supply is controlled. Since 2007, in South-West of France, natural and sown grass covers under the row have been compared, on experimental plots, to chemical weeding. Several gra...

Dans le cadre d’un projet Interbio financé par la région Midi-Pyrénées, l’IFV Sud-Ouest a testé en 2010, l’efficacité de 3 préparations biologiques (d’origine marine, végétale et animale) appliquées par voie foliaire sur vigne, pour corriger le statut azoté des moûts. Malgré des formulations azotées (à base d’ion ammonium et d’acides aminés) moins...

Since their discovery in white Sauvignon wines by teams from the Bordeaux oenology faculty (Tominaga, 1998), varietal thiols have been the object of numerous studies. Four varietal thiols are currently recognized in wines: 4-methyl-4-mercaptopentan-2-one (4MMP), 4-methyl-4-sulfanylpentan-2-ol (4MMPOH), 3-mercaptohexanol (3MH) and 3-mercaptohexyl ac...

RÉSUMÉ La perception aromatique des vins de Colombard produits dans le vignoble de Gascogne provient principalement d'une surexpression de deux thiols variétaux : le 3-mercaptohexan-1-ol (3MH) et le 3-mercaptohexylacetate (3MHA). Le but de cette étude est de comprendre les leviers qui influencent la qualité aromatique d'un vin blanc de Colombard. A...

Increasing varietal thiols concentration in Sauvignon blanc wines using a skin contact enzyme. Varietal thiols are pleasant odorant molecules found in varieties such as Sauvignon blanc and Colombard (Tominaga, 1998). These molecules have also been identified in other varieties such as Gros and Petit Manseng (Dagan, 2006), Melon, Semillon, Muscat an...

The aim of these studies is to evaluate the impact of nitrogen and sulfur foliar applications at the vineyard on the presence of varietal thiols in white and rosés wines. Nitrogen pulverization at the veraison phenological stage improves significantly grape nitrogen status which is known to be a key factor of the varietal thiols release in wine. Al...

The aromatic sensing of Colombard wine produced in the Gascony vineyard, mainly comes from two varietal thiols: 3-mercaptohexan-1-ol (3MH) and 3-mercaptohexylacetate (3MHA). The analysis of these compounds in wine needs very specific high performance equipments and methodologies which are very efficient for research and experiment but not available...

RESUME : Cette étude a pour objectif de tester l'effet au champ de l'exposition des grappes sur le potentiel aromatique des raisins et des vins issu de deux variétés blanches, le Melon B en Val de Loire et le Colombard B dans le Sud-Ouest de la France. L'exposition des grappes est la conséquence d'une opération en vert au vignoble (effeuillage), d'...

L'originalité de l'étude repose sur la faisabilité d'une vendange mécanique de vignes ayant subit une taille de la branche à fruit dans le cadre d'une production de vins blancs secs. Les essais ont été menés en 2006 sur une de cépages Mauzac blanc conduite en Guyot simple présentant des rendements naturels élevés. La récolte constituée de raisins p...

This experiment tries to characterize the role of soil, climate and harvest date on the composition of grape-derivated thiols, 3-mercapto-hexanol (3MH) and 3-mercapto-hexile acetate (A3MH), in the white wines from Colombard varieties in Gascony (SouthWest of France). A network of 6 plots has been observed since 1999 on different pedologic units. Th...

Cette étude compare la conduite de la vigne en Espalier habituelle de la région Midi-Pyrénées (taille guyot double) avec deux systèmes déployés adaptés des systèmes Scott-Henry et Smart-Dyson utilisant une division verticale du feuillage dans le plan de palissage. Les parcelles expérimentales sont constituées de dix pieds par bloc et de six blocs e...

The study uses 8 experimental places trained on vertical trellis system in 4 vineyards of the south –west of France : AOC Gaillac (cv Duras), AOC Fronton (cv Négrette), AOC Cahors (cv Malbec), VDP Côtes de Gascogne (cv Colombard). The exposed leaf area is estimated by the measurement of the canopy external area (SECV). This study shows differences...

This paper aims at providing an easy, fast and non-destructive method for the early estimation of vineyard yield. The proposed method takes advantage of the correlation between the bunch volume at different phenological stages and its weight at harvest. Experimental measurements of the grape bunch height and circumference were carried out manually,...

Correspondance : vidaljc@supagro.inra.fr Article également publié dans la Revue Française d'Oenologie 2001 n°190 : 24-31

Abstract part 1 The aim of this study is the characterization of addition of oxygen in wine during the sequence of bottling operations. The work was performed in the Languedoc-Roussillon region at three bottling companies that handle large volumes of wine. The use of Clark type polarography probes upstream and downstream of the apparatus tested ena...