<p style="text-align: justify;"><strong>Aims</strong>: The impact of water deficit stress on vine shoot growth, berry weight, grape composition and overall vintage quality was investigated in Bordeaux vineyards. Methods for assessing water deficit stress were compared.</p><p style="text-align: justify;"><strong>Methods and results</strong>: Vine water status was assessed on three soil types during four vintages by means of stem water potential and carbon isotope discrimination measured on grape sugar. Regional water deficit was compared for a range of over 30 vintages by means of water balance modelling. It was shown that water deficit stress anticipated shoot growth slackening, limited berry weight and enhanced berry anthocyanin content. Berry sugar content was greatest when water deficit was mild. It was shown that stem water potential measurements and carbon isotope discrimination are accurate tools for assessing vine water status at plot scale. Seasonal water deficit at a regional scale can be correctly estimated by water balance models. Vintage quality in Bordeaux is determined by the intensity of water deficit stress rather than by the level of the temperatures.</p><p style="text-align: justify;"><strong>Conclusions</strong>: Vine phenology and grape ripening are highly dependent on water uptake conditions. Mild water deficit stress enhances grape quality for the production of red wines. Vine water status can accurately be assessed by means of stem water potential or carbon isotope discrimination measured on grape sugars. Quality losses through severe water stress can be avoided through the use of drought-adapted plant material, appropriate canopy management, yield reduction or the implementation of deficit irrigation.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This study shows the key role of water deficits in the production of quality grapes for red wine production. Methods for assessing vine water status are compared and discussed. Among many existing methods, the accuracy of stem water potential, carbon isotope discrimination measured on grape sugar and water balance modelling are emphasized.</p>

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<p style="text-align: justify;"><strong>Aims</strong>: It is well known that vine nitrogen deficiency can negatively impact on aroma in white wines. Soil nitrogen fertilization enhances aroma expression, but it also increases vine vigour and susceptibility to grey rot. The aim of this work was to investigate the impact of foliar nitrogen as well as foliar nitrogen and sulphur applications on aromatic expression, vigour and susceptibility to grey rot of Vitis vinifera L. cv. Sauvignon blanc.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The impact of foliar nitrogen (N) and sulphur (S) application on aromatic expression of Vitis vinifera L. cv. Sauvignon blanc has been investigated. On a plot where vine nitrogen status is naturally low and water availability not limiting, foliar nitrogen and sulphur fertilization (10 kg/ha of N and 5 kg/ha of S) increased yeast available nitrogen content. Vine vigour and maturity level of grapes were not modified compared to the control. The wines produced from N+S vines contained more volatile thiols and glutathione. These results were confirmed by a tasting of wines produced with grapes from the experimental plots. Foliar nitrogen fertilization alone (10 kg/ha of N) also increased Sauvignon blanc aromatic expression, but less so than the N + S treatment.</p><p style="text-align: justify;"><strong>Conclusions</strong>: Foliar N and foliar N + S applications can enhance aromatic expression in Vitis vinifera L. cv. Sauvignon blanc wines without increasing vine vigour and infestation by grey rot.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: Vine nitrogen deficiency can negatively impact on grape aroma potential. Soil nitrogen application can increase vine nitrogen status, but it has several drawbacks: it increases vigour and enhances Botrytis susceptibility. This study shows that foliar N and foliar N + S applications can improve vine nitrogen status and enhance aroma expression in Sauvignon blanc wines without the negative impact on vigour and Botrytis susceptibility. Although this study was carried out on Sauvignon blanc vines, it is likely that foliar N or foliar N + S applications will have similar effects on other grapevine varieties containing volatile thiols (Colombard, Riesling, Petit Manseng and Sémillon).</p>

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<p style="text-align: justify;"><strong>Aims</strong>: Differences in wine flavour proceed primarily from grape quality. Environmental factors (climate, soil), cultivars and training systems modify many grape and wine quality traits. Metabolic profiling based on proton nuclear magnetic resonance (1H-NMR) spectra has been proved to be useful to study multifactorial effects of the vine environment on intricate grape quality traits. The capacity of this method to discriminate the environmental effects on wine has to be demonstrated.</p><p style="text-align: justify;"><strong>Methods and results</strong>: : 1H-NMR spectra were made from wines produced with grapes harvested at maturity of three cultivars (Cabernet-Sauvignon, Cabernet franc and Merlot) and three soil types (gravely, sandy and clayey) during two vintages (2002 and 2003). Data were analysed by multivariate statistical methods. Principal component analysis applied on the NMR spectra data were not always able to separate satisfactorily wines from the 3 soil types. Conversely, partial least square analysis separated clearly the 3 soil types independently of the vintage and cultivar.</p><p style="text-align: justify;"><strong>Conclusion</strong>: By comparing the NMR signals that contribute to the two first axes of the PCA and PLS analyses, a significant soil effect on NMR signals in wines is reported. However, the effect of the vintage on wine composition was greater then the effect of the soil type.</p><p style="text-align: justify;"><strong>Significance and impact of study</strong>: After validation on a larger number of wine samples this chemical profiling will be a useful new method to the qualify wines in relation to climate, soil, and cultivar effects which contribute to the terroir.</p>

Abstract. Soil water availability deeply affects plant physiology. In viticulture it is considered as a major contributor to the "terroir" expression. The assessment of soil water in field conditions is a difficult task especially over large surfaces. New techniques, are therefore required to better explore variations of soil water content in space and time with low disturbance and with great precision. Electrical Resistivity Tomography (ERT) meets these requirements, for applications in plant sciences, agriculture and ecology. In this paper, possible techniques to develop models that allow the use of ERT to spatialise soil water available to plants are reviewed. An application of soil water monitoring using ERT in a grapevine plot in Burgundy (north-east of France) during the vintage 2013 is presented. We observed the lateral heterogeneity of ERT derived Fraction of Transpirable Soil Water (FTSW) variations, and differences in water uptake depending on grapevine water status (leaf water potentials measured both at predawn and at solar noon and contemporary to ERT monitoring). Active zones in soils for water movements were identified. The use of ERT in ecophysiological studies, with parallel monitoring of plant water status, is still rare. These methods are promising because they have the potential to reveal a hidden part of a major function of plant development: the capacity to extract water from the soil.

<p style="text-align: justify;"><strong>Aims</strong>: The first aim of this investigation was to determine whether red- and black-berry fruit aromas were specific to red wines. The second aim was to study their contribution to the red Bordeaux wine concept.</p><p style="text-align: justify;"><strong>Methods and results</strong>: In experiment 1, red wines were presented to expert assessors in dark, then in clear glasses. Assessors selected wines where they detected specific red-/black-berry aromas and then rated the perceived intensity. Results showed a statistically significant impact of visual input on both detection and intensity rating of red-/black-berry aromas in red wines. As part of experiment 2, both red and white wines were rated using dark glasses only. Globally, red-/black-berry aromas were shown to be more specific to red wines. Finally, in experiment 3, red Bordeaux wine experts assessed the degree to which 21 wines (9 red Bordeaux wines, 8 red wines of various origins and 4 white wines) corresponded to their own red Bordeaux wine concept, and then evaluated the intensity of 4 fruity descriptors they had detected in these wines. The results revealed that the expert assessors shared coherent olfactory concepts of red Bordeaux wines, which enabled them to distinguish the red Bordeaux from the other wines presented.</p><p style="text-align: justify;"><strong>Conclusions</strong>: The existence of a red-/black-berry character specific to red wines was demonstrated. Moreover, it was shown for the first time that red Bordeaux wines tend to have their own sensory space. The distinctive character of these wines was found to relate to « black-berry » and « jammy fruit » olfactory descriptors.</p><p style="text-align: justify;"><strong>Significance and impact of the study</strong>: This study clarified our knowledge of the fruity olfactory descriptors specific to red wines in general and red Bordeaux wines in particular.</p>

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