Vineyard management practices are known to affect fruit composition and resultant wines, in part, by altering fruit volatiles. Methods currently used to evaluate the impact of vineyard practices on grape/wine composition include measuring physico-chemistry indices and performing wine sensory analyses. These activities are both time-consuming and destructive. Two electronic nose (ENose) systems: a hand-held conducting polymer-based and a portable surface acoustic wave-based systems were investigated as grape monitoring tools. Vineyard treatments included the effect of canopy side (East vs. West and North vs. South), cluster thinning (unthinned, 1 cluster/shoot, and 1 & 2 cluster/shoot) and ethanol spray (5% v/v) on Cabernet franc, Merlot and both varieties respectively. ENose data were obtained in the field (over two growing seasons for canopy side and in 2008 for cluster thinning and ethanol spray) and laboratory (2007 for canopy side), across different sampling dates and compared with nine-grape/eight-wine chemistry assays, GC/MS (cluster thinning) and wine aroma sensory evaluations (triangular difference testing). ENose results demonstrated 100% significant differences between all Cabernet franc and Merlot treatments. Grape/wine chemistry indices, for both Cabernet franc and Merlot, did not differ among treatments (except ethanol treatment) across sampling dates or growing seasons and vineyard management practices. Wine aroma sensory evaluations demonstrated only limited differences (3 out of 8 comparisons: East vs. West, 1 cluster/shoot vs. 1 & 2 clusters/shoot and 1 cluster/shoot and 1 & 2 clusters/shoot). The high level of discrimination by ENose systems may provide opportunities to enhance the understanding of vineyard management activities. / Master of Science in Life Sciences

Vineyard management practices are known to affect fruit composition and resultant wines, in part, by altering fruit volatiles. Methods currently used to evaluate the impact of vineyard practices on grape/wine composition include measuring physico-chemistry indices and performing wine sensory analyses. These activities are both time-consuming and destructive. Two electronic nose (ENose) systems: a hand-held conducting polymer-based and a portable surface acoustic wave-based systems were investigated as grape monitoring tools. Vineyard treatments included the effect of canopy side (East vs. West and North vs. South), cluster thinning (unthinned, 1 cluster/shoot, and 1 & 2 cluster/shoot) and ethanol spray (5% v/v) on Cabernet franc, Merlot and both varieties respectively. ENose data were obtained in the field (over two growing seasons for canopy side and in 2008 for cluster thinning and ethanol spray) and laboratory (2007 for canopy side), across different sampling dates and compared with nine-grape/eight-wine chemistry assays, GC/MS (cluster thinning) and wine aroma sensory evaluations (triangular difference testing). ENose results demonstrated 100% significant differences between all Cabernet franc and Merlot treatments. Grape/wine chemistry indices, for both Cabernet franc and Merlot, did not differ among treatments (except ethanol treatment) across sampling dates or growing seasons and vineyard management practices. Wine aroma sensory evaluations demonstrated only limited differences (3 out of 8 comparisons: East vs. West, 1 cluster/shoot vs. 1 & 2 clusters/shoot and 1 cluster/shoot and 1 & 2 clusters/shoot). The high level of discrimination by ENose systems may provide opportunities to enhance the understanding of vineyard management activities. / Master of Science

In 2009 and 2010 a split, split, split plot experiment with training system, VSP or Smart-Dyson Ballerina (main plot), N, 0 or 33.6 kg/ha (split), crop level, 14.0, 18.7, or 23.4 clusters/m/canopy (split), clone, Cabernet Franc 1,4, 8 and 214 treatments with five replications were established in Union County, Illinois on mature vines. The Smart-Dyson Ballerina training system produced a Ravaz index that was 89% and 28% bigger compared to the VSP respectively in 2009 and 2010. In 2009, the Smart-Dyson Ballerina produced a 80% bigger yield than VSP and in 2010 yield was also larger, but influenced by both training system and crop level. Maintaining a balanced vineyard can increase profit for the grower by up to $6,356.87/ha.

Current fruit-zone management recommendation in the eastern US aims for 1-2 basal shoot leaf layers after fruit set to limit fungal disease and sunburn incidence, and prevent extreme heating of grapes. The goal of this work was to assess if fruit-zone leaf removal to an uncommonly greater extent, and/or at an earlier phenological stage, would favorably alter yield components or fruit composition in three popularly grown, red-fruited, Bordeaux varieties – Cabernet franc, Petit Verdot, and Cabernet Sauvignon. Pre-bloom leaf removal to various extents reduced crop yield by 41-78% when compared to no leaf removal across seasons and varieties. Pre-bloom leaf removal implementation in consecutive seasons tended to further reduce crop yield components compared to implementation in the first year. Pre-bloom leaf removal tended to reduce cluster compactness and bunch rot incidence when compared to post-fruit set and no leaf removal. Basal leaf removal to the greatest extents inconsistently reduced soluble solids and titratable acidity across varieties and seasons. Pre-bloom and post-fruit set leaf removal to the greatest extent consistently increased total grape phenolics and anthocyanins compared to no leaf removal in Cabernet Sauvignon, but inconsistently increased total grape phenolics compared to no leaf removal in Cabernet franc and Petit Verdot. Basal leaf removal to the greatest extents tended to increase the synthesis and degradation of carotenoids more consistently than no leaf removal, and this was particularly true for zeaxanthin. Petit Verdot and Cabernet franc wine color and aroma were inconsistently distinguishable between leaf removal treatments, and color intensity was rated higher in wines made with fruit from pre-bloom leaf removal compared to modest post fruit-set leaf removal plots. Waiting until after fruit set to remove fruit-zone leaves maintained crop yield and offered comparable improvements in fruit composition to pre-bloom leaf removal. Pre-bloom leaf removal of no more than four leaves is recommended to limit crop yield reduction, and modestly improve fruit composition. This work showed that fruit-zone leaf removal does not need to be conservative in the eastern US, particularly because the climate does not appear to be detrimental to fruit composition, and open fruit-zones reduce grape fungal disease incidence. / Ph. D.

Le constat que la qualité du vin prend ses origines dans le vignoble est bien enraciné dans la culture européenne. De cette façon, le zonage viticole est à la base de la caractérisation et de la valorisation des produits de terroir tenant compte de l'attention croissante des consommateurs envers les aliments fonctionnels (avec des propriétés nutritionnelles et des bienfaits sur la santé due à leur richesse en molécules comme vitamines et polyphénols). L'enjeu général s'inscrit dans une meilleure compréhension des mécanismes qui sont à la base du fonctionnement de la vigne et de la qualité du vin ainsi que cette étude vise la recherche des terroirs où le taux des stilbènes des vins est le plus élevé. Nous avons considéré deux réseaux de parcelles, l'un de Cabernet franc dans le Saumurois-Touraine (France) et l'autre de Sangiovese di Romagna (Italie). La caractérisation des terroirs et l'analyse des stilbènes des vins issus de chaque parcelle ont été étudiées sur de plusieurs années (de 2003 à 2005 en France, en 2008 et 2009 en Italie) Nous avons identifié cinq UTB dans le Saumurois-Touraine et trois UTB dans le Sangiovese di Romagna. Nos résultats montrent bien que le terroir affecte le métabolisme des stilbènes d'une façon importante et en particulier la teneur en transresvératrol dans le Saumurois-Touraine dépend pour le 58% du terroir. L'effet du millésime (climat) est dominant tandis que l'effet du sol et du sous-sol est secondaire au climat. L'altitude de la parcelle et la teneur en calcaire actif du sol favorisent l'augmentation du resvératrol des vins. La texture du sol affecte le métabolisme des stilbènes ainsi que la teneur en argile augmente la concentration du vin en ces molécules.