Saint-Martin-Vésubie, France
Saint-Martin-Vésubie, France

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Petit A.-N.,University of Reims Champagne Ardenne | Vaillant-Gaveau N.,University of Reims Champagne Ardenne | Walker A.-S.,French National Institute for Agricultural Research | Leroux P.,French National Institute for Agricultural Research | And 4 more authors.
Crop Protection | Year: 2010

Botrytis bunch rot of grapes is mainly controlled by applying fungicides at three crop growth stages: the end of flowering (BBCH 68), bunch closure (BBCH 77) and the beginning of veraison (BBCH 81). The hydroxyanilide derivative fenhexamid is among the most effective fungicides registered to control Botrytis cinerea. Its effectiveness was examined in relation to spray timing, fungicide resistance and defense responses of grapevine. Overall, the earlier fenhexamid was applied, the more effective it was at controlling B. cinerea. Frequencies of B. cinerea strains which were resistant to fungicides were evaluated at harvest. The frequencies of resistant phenotypes were similar among treatments and years with the exception of a class of multidrug resistant strain (MDR 2) whose frequency appeared to increase after fenhexamid applications. If current spray programs including fenhexamid appear to control bunch rot at the current MDR frequency, a propagation of MDR 2 strains might lead to a decline in disease control. Finally, defense responses were studied in grapevine flowers/berries following fenhexamid application. None of the defense processes tested was induced in flowers/berries at stages 68 and 77. Only an increase in chitinase activity was observed in treated-berries at stage 81, suggesting that fenhexamid effectiveness was not related to a stimulation of defense responses. © 2010 Elsevier Ltd.


Parker A.,Marlborough Wine Research Center | Parker A.,University of Bordeaux 1 | Parker A.,Lincoln University at Christchurch | Parker A.,Canterbury Agriculture and Science Center | And 27 more authors.
Agricultural and Forest Meteorology | Year: 2013

Understanding differences in phenology for varieties of a given species is important for making informed decisions on variety choice in the context of climate change and breeding new cultivars. Phenological models that incorporate temperature as a key environmental factor can be used to describe the differences in phenological timing between cultivars. This paper outlines a methodology, based on a phenological model, for classifying the timing of flowering and veraison for a substantial number of varieties of the grapevine (Vitis vinifera L.). 95 varieties were characterized for flowering and 104 varieties for veraison. Various statistical measures were used to assess the performance and predictions of the model at the varietal level: model efficiency, root mean squared error and confidence intervals. The methodology might be used to understand varietal differences for other species in future studies. Model outputs can be used in combination with predicted climate change scenarios to assess the suitability of varieties under climate conditions of the future. © 2013 Elsevier B.V.


Petit A.-N.,University of Reims Champagne Ardenne | Vailant-Gaveau N.,University of Reims Champagne Ardenne | Walker A.-S.,French National Institute for Agricultural Research | Leroux P.,French National Institute for Agricultural Research | And 4 more authors.
Phytopathologia Mediterranea | Year: 2011

Botrytis bunch rot of grapes is mainly controlled by applying fungicides at three crop stages: the end of flowering (BBCH 68), bunch closure (BBCH 77) and the beginning of veraison (BBCH 81). The phenylpyrroles derivative fludioxonil is among the most effective fungicides registered to control Botrytis cinerea. Its effectiveness was investigated in relation to spray timing, fungicide resistance and defence responses of grapevine. Frequencies of B. cinerea strains which were resistant to fungicides were evaluated at harvest. The frequencies of resistant phenotypes were similar in all treatments except for a class of multidrug resistant strains (MDR 1) whose frequency increased after fludioxonil applications. None of the treatments tested induced defence responses in flowers/berries after fungicide application, suggesting that fludioxonil effectiveness was not related to a stimulation of plant defence processes. The standard program of three fungicide applications provided the best control of B. cinerea in the Champagne region in comparison with a single treatment of fludioxonil at any of the crop stages tested.


Roullier-Gall C.,University of Burgundy | Roullier-Gall C.,Helmholtz Center for Environmental Research | Roullier-Gall C.,TU Munich | Witting M.,Helmholtz Center for Environmental Research | And 7 more authors.
Food Chemistry | Year: 2016

The oxygenation of Champagne wine after 4 and 6 years of aging on lees in bottle was investigated by FTICR-MS and UPLC-Q-TOF-MS. Three levels of permeability were considered for the stoppers, ranging from 0.2 to 1.8 mg/L/year of oxygen transfer rate. Our results confirmed a good repeatability of ultra-high resolution FTICR-MS, both in terms of m/z and coefficient of variation of peak intensities among biological replicates. Vintages appeared to be the most discriminated features, and metabolite annotations suggested that the oldest wines (2006) were characterized by a higher sensitivity towards oxygenation. Within each vintage, the oxygenation mechanisms appeared to be different for low and high ingresses of oxygen, in agreement with the hormesis character of wine oxygenation. In the particular case of single variety wines and for a given level of stopper permeability, our results also showed that variety discrimination could be easily achieved among wines. © 2016 Elsevier Ltd. All rights reserved.


PubMed | Comite Interprofessionnel du Vin de Champagne, TU Munich, Helmholtz Center for Environmental Research and University of Burgundy
Type: | Journal: Food chemistry | Year: 2016

The oxygenation of Champagne wine after 4 and 6 years of aging on lees in bottle was investigated by FTICR-MS and UPLC-Q-TOF-MS. Three levels of permeability were considered for the stoppers, ranging from 0.2 to 1.8 mg/L/year of oxygen transfer rate. Our results confirmed a good repeatability of ultra-high resolution FTICR-MS, both in terms of m/z and coefficient of variation of peak intensities among biological replicates. Vintages appeared to be the most discriminated features, and metabolite annotations suggested that the oldest wines (2006) were characterized by a higher sensitivity towards oxygenation. Within each vintage, the oxygenation mechanisms appeared to be different for low and high ingresses of oxygen, in agreement with the hormesis character of wine oxygenation. In the particular case of single variety wines and for a given level of stopper permeability, our results also showed that variety discrimination could be easily achieved among wines.


Le Maguet J.,Comite Interprofessionnel du Vin de Champagne | Le Maguet J.,CNRS Vine Health and Wine Quality | Le Maguet J.,University of Strasbourg | Beuve M.,CNRS Vine Health and Wine Quality | And 5 more authors.
Phytopathology | Year: 2012

Grapevine leafroll disease is caused by grapevine leafroll-associated viruses (GLRaVs). These viruses are common in vineyards worldwide and often associated with vitiviruses that are involved in the rugose wood complex of grapevine. Ten mealybug species are known as vectors of one or several of these grapevine viruses, including the apple mealybug Phenacoccus aceris which is widespread in Holarctic regions and able to transmit Grapevine leafroll-associated virus-1 and -3 (GLRaV-1 and -3). Our aim was to characterize the transmission features of leafroll viruses by Phenacoccus aceris in order to better understand the contribution of this mealybug to leafroll epidemics. Results showed that Phenacoccus aceris is able to transmit GLRaV-1, -3, -4, -5, -6, and -9 to grapevine but not GLRaV-7. This is the first report of GLRaV-6 transmission by a mealybug. Also, for the first time it was shown that Phenacoccus aceris could vector vitiviruses Grapevine virus A (GVA) and Grapevine virus B (GVB). First instar nymphs were the most efficient stage in transmitting GLRaV-1, -3, and GVA. This research sheds light on the transmission biology of grapevine viruses by Phenacoccus aceris and represents a step forward to leafroll disease management. © 2012 The American Phytopathological Society.


Pons M.,University of Bordeaux Segalen | Dauphin B.,University of Bordeaux Segalen | La Guerche S.,University of Bordeaux Segalen | Pons A.,University of Bordeaux Segalen | And 7 more authors.
Journal of Agricultural and Food Chemistry | Year: 2011

Analysis of wines from different grape varieties marked by sometimes intense aromatic nuances of fresh mushroom was performed by gas chromatography coupled with olfactometry. This analysis has led to the identification of several odoriferous zones, which were recalling a fresh mushroom odor. Two trace compounds responsible for these odoriferous zones, 1-nonen-3-one and 1-octen-3-one, have been identified and their content has been determined by using either a multidimensional gas chromatography technique coupled to olfactometry and mass spectrometry detection (in the case of 1-nonen-3-one) or the preparation of the derivative with O-2,3,4,5,6- pentafluorobenzylhydroxylamine hydrochloride in the presence of the deuterated form, as the internal standard (in the case of 1-octen-3-one), then gas chromatography coupled to mass spectrometry detection. The assays allowed the quantification of these compounds at concentration levels sometimes well above their detection and recognition olfactory threshold. We show that adding nitrogen compounds to the altered wines, such as an amino acid (glycine) or a tripeptide (glutathione), led to lower concentrations of 1-octen-3-one in wines and diminished smell of fresh mushrooms. The study of the reaction in a model medium, whose composition is close to wine, by liquid chromatography coupled to mass spectrometry demonstrated the formation of adducts between 1-octen-3-one and glycine, and 1-octen-3-one and glutathione characterized by NMR. © 2011 American Chemical Society.


Vaillant-Gaveau N.,CNRS Research Unit on Grapevine and Wines in Champagne | Wojnarowiez G.,CNRS Research Unit on Grapevine and Wines in Champagne | Petit A.-N.,CNRS Research Unit on Grapevine and Wines in Champagne | Jacquens L.,CNRS Research Unit on Grapevine and Wines in Champagne | And 3 more authors.
Journal International des Sciences de la Vigne et du Vin | Year: 2014

Aim: The present study was conducted in grapevines to evaluate the influence of source/sink disturbance on reserve restoration in the entire plant (trunk, roots) and the consequences on reproduction, yield, sugar yield, potential alcohol content and total acidity over four successive years of treatment. Methods and results: At véraison, either total defoliation or total fruit removal was performed on Chardonnay plants grown in vineyards. The impact was measured each year on reproductive parameters and after four years on both plant weight and carbohydrate content. Defoliation induced an alteration in carbohydrate distribution in the entire plant, as revealed by decrease of starch content and parallel increase of soluble sugar content. These modifications affected the number of inflorescences/clusters per plant the year after. By contrast, fruit removal resulted in a significant increase of carbohydrate reserves in the whole plant, although the efficiency of sexual reproduction was not improved the year after. Conclusion: Results confirm the close correlation between carbohydrate reserves and the efficiency of sexual reproduction. Moreover, grapevine is able to adapt the number of both inflorescences and flowers according to the amount of available carbohydrate reserves in perennial organs. Significance and impact of the study: The quality of the crop is affected by defoliation, as shown by the decrease in yield and sugar yield. However, the impact on potential alcohol content and total acidity was less pronounced. © Vigne et Vin Publications Internationales (Bordeaux, France).


Bourgeon M.A.,CNRS Agroecology Lab | Paoli J.N.,CNRS Agroecology Lab | Villette S.,CNRS Agroecology Lab | Debuisson S.,Comite Interprofessionnel du Vin de Champagne | And 3 more authors.
Precision Agriculture 2015 - Papers Presented at the 10th European Conference on Precision Agriculture, ECPA 2015 | Year: 2015

In precision viticulture, multispectral imaging systems are currently used in remote sensing for vineyard vigor characterization but few are employed in proximal sensing. This work presents the potential of a proximal multispectral imaging system mounted on a track-laying tractor equipped with a Greenseeker RT-100 to provide an normalized difference vegetation index (NDVI) index. The camera acquired visible and near-infrared images which were calibrated in reflectance. Vegetation indices were computed and compared to Green seeker data. From two of the resulting datasets, a spatio-temporal study of foliage description through both optical systems is presented. This first study assessed the proximal imagery with regard to the similarity of results.

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