Memoria para optar al Título Profesional de Ingeniero Agrónomo. Mención: Enología.

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

Thesis (MScAgric)--Stellenbosch University, 2014. / ENGLISH ABSTRACT: Irrigation scheduling decisions are based either on the direct measurement of soil water status (SWS) or on physiological measurements like plant water status (PWS). Soil based measurements are quick and easily automated, but the plant response for a particular quantity of soil moisture varies as a complex function of evaporative demand. A plant-based approach measures the plant stress response directly, but is an integration of environmental effects as well. In contrary to soil-based methods, plant based measurements can indicate when to irrigate, but not the quantity. Pre-dawn leaf water potential (ΨPD) is determined mostly by the soil moisture level, and can serve as a measure of static water stress in plants and an index of bulk soil water availability or even as an estimate of soil water potential at the root surface. Therefore it should be possible to establish a link between SWS and PWS, but it is largely unknown how stable the link in a heterogeneous vineyard would be, and how the grapevine vegetative and reproductive response relates to this link. Plant water status plays a large role in determining vigour and yield of the plant. The levels of PWS are influenced by irrigation, but it was mostly affected by the season and vine location in the vineyard. More negative plant water potentials reduced vigour, but had a less pronounced effect on yield, while also reducing overall wine quality. Vigour variability in the vineyard was largely attributed to soil heterogeneity, which seemed to have a strong effect on SWS. SWS measurements were calibrated according to the observed variability, increasing the accuracy of measurements significantly. Soil water content values were used to establish a link between SWS and PWS. This link was determined over time using nine plots, consisting of rain-fed and irrigated regimes, in variable vigour areas. A non-linear relationship was found between ΨPD and percentage extraction of plant available water for rain-fed plots. When irrigation was applied, no correlation could be found. In this study, for Merlot in the Stellenbosch region, PWS differences affected vigour, and to a lesser extent yield, as well as wine quality. More negative plant water potentials reduced vigour more in high vigour areas than in lower vigour areas, which in turn led to unbalanced vegetative: reproductive ratios. This disturbed vine balance may have had a bigger impact on wine quality than PWS levels. Therefore a well-managed and balanced vine is able to withstand more stress, with less detrimental effects. This study also highlights the danger of limiting the assessment of soil and plant water status conditions to point measurements in vineyards with high levels of vigour variability. / AFRIKAANSE OPSOMMING: Besluite rakende die skedulering van besproeiing word gewoonlik gebaseer op die direkte meting van grondwaterstatus (GWS), of op fisiologiese metings soos byvoorbeeld plantwaterstatus (PWS). Grond gebaseerde metings is relatief vinnig en maklik om te outomatiseer, maar die plantrespons vir ʼn spesifieke grondwaterinhoud varieer as ʼn komplekse funksie van dampdruktekorte. ‘n Plantgebaseerde benadering meet die plantstresreaksie direk, maar is ʼn integrasie van omgewingstoestande. In teenstelling met grondgebaseerde metodes, kan plantgebaseerde metodes aandui wanneer om te besproei, maar nie die hoeveelhede wat besproei moet word nie. Voorsonsopkoms blaarwaterpotensiaal (ΨPD) word grootliks deur die grondwaterinhoud bepaal, en kan as ʼn maatstaf van statiese waterspanning in plante en as ʼn indeks van bulk grondwaterbeskikbaarheid dien, of selfs as ʼn benadering van die grondwaterpotensiaal by die worteloppervlak. Dit behoort dus moontlik te wees om ʼn verwantskap te bepaal tussen GWS en PWS, maar dit is grootliks onbekend hoe stabiel hierdie verwantskap sal wees in ʼn heterogene wingerd, asook hoe die wingerdstok se vegetatiewe en reproduktiewe reaksie die verwantskap kan beïnvloed. Plantwaterstatus speel ʼn groot rol in die bepaling van groeikrag en opbrengs in die wingerdstok. Die vlakke van plantwaterstatus word deur besproeiing beïnvloed, maar word skynbaar meesal deur die seisoen en wingerdstok se ligging in die wingerd bepaal. Meer negatiewe plantwaterpotensiaalvlakke het gelei tot laer groeikrag, maar het ʼn minder uitgesproke effek gehad op opbrengs, terwyl dit in die algemeen wynkwaliteit verswak het. Groeikrag variasie in die wingerd kon grootliks aan grond heterogeniteit toegeskryf word, wat skynbaar ʼn sterk invloed op grondwaterstatus gehad het. Grondwaterstatus metings is gekalibreer volgens die variasie wat waargeneem is, wat die akkuraatheid van metings beduidend verhoog het. Grondwaterinhoud waardes is gebruik om ʼn verwantskap aan te dui tussen SWS en PWS. Hierdie verwantskap is oor tyd bepaal vir nege persele, wat bestaan het uit droëland asook besproeide persele, in areas waarvan die groeikrag verskil het. ʼn Nie-liniêre verband is gevind tussen ΨPD en die persentasie onttrekking van plantbeskikbare water vir die droëland persele. Waar besproei was, kon geen verband gevind word nie. In hierdie studie, vir Merlot in die Stellenbosch area, het PWS vlakke groeikrag en tot ʼn mindere mate opbrengs en wynkwaliteit beïnvloed. Meer negatiewe plantwaterpotensiaal vlakke het groeikrag meer beïnvloed in hoër groeikrag areas as in die laer groeikrag areas, wat ook gelei het tot ongebalanseerde vegetatiewe:reproduktiewe verhoudings. Hierdie versteurde balans in die wingerdstokke kon dalk ʼn groter impak op wynkwaliteit gehad het as PWS vlakke. Daar moet dus gepoog word om goed bestuurde en gebalanseerde wingerdstokke te hê, sodat strestoestande beter weerstaan kan word met minder nadelige gevolge. Die studie beklemtoon ook die gevaar verbonde daaraan om die bepaling van grond- en plantwaterstatus te beperk tot puntmetings in wingerde met groot variasie in groeikrag.

La connaissance de la composition phénolique du Cabernet-Sauvignon (CS) et du Merlot (M) dans la région vitivinicole du bordelais a un intérêt majeur pour définir la structure et la qualité tannique (astringence et amertume) des raisins et des vins. La composition en tanins et anthocyanes de raisins et de vins issus du Cabernet Sauvignon et du Merlot ainsi que leur perception tannique ont été recherchées. L’étude raisins a été réalisée pour cinq parcelles de la région bordelaise (Pauillac, Margaux, Saint Emilion (1), Saint Emilion (2) Côtes de Bourg) pour trois millésimes consécutifs : 2006, 2007 et 2008 et différents types de sol : Limoneux, Sableux, Limono-Sableux 1, Limono-Sableux 2, Limon argilo-sableux pour le M et Limono-argileux, Sablo-limoneux 1, Limono-sableux, Sablo-limoneux 2 et Limoneux pour le CS. Les monomères [(+)-catéchine (C), (-)-épicatéchine (EC), (-)-épicatéchine-O-gallate] et les oligomères (dimères: B1, B2, B3, B4 et trimère Cat-Cat-Epi) des procyanidines, ont été identifiées et quantifiées pour les extraits de raisins (pépins et pellicules) et pour les vins par CHLP-UV-Fluo. Le pourcentage de galloylation (%G), le pourcentage de prodelphinidines (%P) ainsi que le degré moyen de polymérisation (DPm) des tanins oligomères des raisins et des tannins de vin ont été déterminés par CHLP-UV-SM. L’intensité d’astringence et d’amertume des tanins oligomères des raisins (pépins et pellicules) et des vins ont été estimées par analyse sensorielle. Les anthocyanes monoglucosides [cyanidine-3-O-glucoside (Cy), delphinidine-3-O-glucoside (Dp), paeonidine-3-O-glucoside (Pn), malvidine-3-O-glucoside (Mv), petunidine-3-O-glucoside (Pt)] et les anthocyanes acétylées (paeonidine-3-O-glucoside, malvidine-3-O-glucoside) et coumaroylées (paeonidine-3-O-glucoside, malvidine-3-O-glucoside) ont été identifiées et quantifiées par CLHP-UV-SM dans les extraits de pellicules et dans les vins. L’influence du sol, du millésime, et du cépage (pour les raisins et les vins) ont été explorés. Le millésime, dans les deux cas (raisins et vins), a un effet très significatif et domine celui du cépage (raisins et vins) et celui du sol (raisins) sur la plupart des variables étudiées. Selon le type de sol et le millésime, la qualité tannique des raisins est évaluée. Les pépins de CS issus du sol Limono-sableux présentent une grande variabilité au niveau du DPm (3,8 à 7,2) et au niveau du % G (19,0 à 51,3). Ceux-ci sont plus astringents et amers que les pépins issus des autres types de sols. Les pépins (CS) du millésime 2006 sont plus astringents et amers que ceux des autres millésimes, même s’ils sont caractérisés par des valeurs de DPm et % G deux fois moins élevées que ceux de 2007. Pour les sols Limono-sableux, les pellicules (CS) possèdent les valeurs moyennes de DPm (30,89) et de % G (5,07) les plus élevées et sont perçues comme les plus astringentes. Les pépins de M issus du sol Limono-sableux 1 et du sol Limoneux présentent des DPm maximums de 3,20 et 3,03 ; avec des intensités moyennes d’astringence et d’amertume les plus élevées pour le sol Limono-sableux 1. Pour les pépins de M, les intensités d’astringence sont du même ordre pour les 3 millésimes. Les pépins (M) de 2007 possèdent le % G le plus élevé (33,34) et sont perçus plus amers par rapport aux autres millésimes. Les pellicules de M des sols sableux sont plus astringentes avec une variation forte du % P (3,8 à 14,0). Pour le M, les pellicules issues du sol Limoneux sont moins astringentes et se caractérisent par un DPm moins élevé (10,42) par rapport aux autres sols. Pour les pépins, le CS présente un DPm (4,15) et un % G (26,12) plus élevés que celui du M (2,74 et 21,22 %). Pour les pellicules, le CS se caractérise par un DPm (22,85), un % G (3,24 %) et un % P (14,99 %) plus élevés que ceux de M (DPm = 19,42, % G = 1,31 %, % P= 5,54). Pour les trois millésimes étudiés, le cépage n’a influencé ni l'amertume ni l'astringence pour les pépins et les pellicules. Les différences significatives et consécutives sur la composition en anthocyanes entre CS et M pour les trois millésimes portent sur : la Cy, la Pt, la Pn, la Mv et les anthocyanes acétylées et coumaroylées. Les teneurs en anthocyanes acétylées sont deux fois plus élevées pour le CS (6,99 mg/g), alors que le M présente des teneurs en anthocyanes coumaroylées (3,31 mg/g) plus élevées que celles du CS (1,99 mg/g). L’étude de la qualité tannique sur vins, a été réalisée pour 24 millésimes issus de CS et 7 millésimes issus de M. Les teneurs en composés phénoliques, en anthocyanes, en tanins totaux, en monomères des tanins (C+EC), la teinte, l’IC’ (intensité colorante), le % G, le % P et le DPm ainsi que l’intensité de l’astringence apparaissent comme des données pertinentes pour différencier les vins en fonction du millésime. Des corrélations entre l’âge des vins et : le DPm, la teinte, l’astringence, les teneurs en composés phénoliques totaux, en monomères de tanins (C+EC) et en tanins totaux ont pu être obtenues. La caractérisation qualitative des tanins et des vins est établie par corrélation entre l’astringence et le DPm (R2 = 0,509, p = 0,051, CS ; R2 = 0,780, p = 0,000, M). De plus, le DPm apparaît être un marqueur du millésime (R2 = 0,796, p = 0,000 ; CS et R2 = 0,946, p = 0,000 ; M). Nous proposons une échelle reliant le DPm des vins en fonction du millésime et de la perception tannique (astringence). Les vins issus du M sont caractérisés par une moindre richesse en composés phénoliques totaux, en tanins, en anthocyanes, en DPm, en % G, en % P ainsi que par une intensité d’astringence moins importante par rapport a ceux de CS. Le TAV (titre alcoométrique volumique, % vol) semble être positivement corrélé à l’amertume (r = 0,39, p < 0,05). / Cabernet-Sauvignon (CS) and Merlot (M) phenolic composition is of paramount importance to grapes and red wines structure and quality (astringency and bitterness) in Bordeaux winegrowing region. Tannins and anthocyanins composition as well as tannin perception have been studied for Cabernet-Sauvignon and Merlot grapes and wines. Grapes study was carried out with samples from five vineyards located in Bordeaux (Pauillac, Margaux, Saint Emilion (1), Saint Emilion (2)and Côtes de Bourg) for three consecutive vintages (2006, 2007 and 2008) and for different soil types (Silty, Sandy, Silty-sandy 1, Silty-sandy 2, Silty clay-sandy for M and Clay-loam, Sandy-silty 1, Silty-sandy, Sandy-silty 2 and Silty for CS). The proanthocyanidin monomers [(+)-catechin (C), (-)-epicatechin (EC), (-)-epicatechin-O-gallatte] and oligomers [dimers: B1, B2, B3, B4 and trimer Cat-Cat-Epi] from grape extracts (seed and skin) and wine were identified and quantified by HPLC-UV-Fluo. Percentage of galloylation (%G), percentage of prodelphinidins (%P) as well as mean degree of polymerization (mDP) of grape tannins oligomers and wine tannins were determined by HPLC-UV-MS. Sensory analysis concerning astringency and bitterness intensity of grape tannins oligomers (skins and seeds) and wines was also performed. The anthocyanic composition of glucosides [cyanidin-3-O-glucoside (Cy), delphinidin-3-O-glucoside (Dp), paeonidin-3-O-glucoside (Pn), malvidin-3-O-glucoside (Mv), petunidin-3-O-glucoside (Pt)] acetylated glucosides (paeonidin-3-O-glucoside, malvidin-3-O-glucoside]) and coumarylic glucosides (paeonidin-3-O-glucoside, malvidin-3-O-glucoside) of skins extracts and wines were analysed by HPLS-MS. Soil, vintage and grape variety influence on the above parameters are explored. The vintage in both cases (grapes and wines), has a significant effect and dominates that of grape variety (grape and wine) and soil (grape). Depending on soil type and vintage, tannins grapes quality is evaluated. CS seeds from Silty-sandy soil present a great variability on mDP (3.8 to 7.2) and on % G (19.0 to 51.3). The above seeds are more astringent and bitter than those from other soil types. The 2006 seeds (CS) are more astringent and bitter than these from the other vintages, even if they are characterized by G % and mDP values two times lower than these of 2007. Skins (CS) of Silty-sandy soils, have the highest mDP (30.89) and % G (5.07) average values and are perceived as more astringent. M seeds from Silty-sandy 1 and Silty soil have the maximum mDP values (3.20 and 3.03); Silty-sandy 1 M seeds present the highest astringency and bitterness intensities. For M seeds, astringency intensities present the same values for the 3 vintages. The 2007 seeds (M) have the highest % G (33.34) and are perceived bitter than those from the other vintages. M skins from Sandy soils are the most astringent with a strong variation on % P (3.8 to 14.0). M skins from Silty soils are less astringent and are characterized by lower mDP values (10.42) than these from other soils. In seeds, CS presents a mDP (4.15) and a % G (26.12) higher than M (2.74 and 21.22 %). CS skins are also characterized by higher mDP (22.85), % G (3.24 %) and % P (14.99 %) values than M (mDP = 19.42, % G = 1.31 % and %, P = 5.54 %). For all three vintages studied, the grape variety does not affect the astringency and bitterness intensity in both skin and seed tannins extracts. The consistent differences between CS and M for the three vintages on anthocyanin composition are on : Cy, Pt, Pn, Mv, acetylated and coumarylic anthocyanin levels. Acetylated anthocyanins values are two times highest for CS (6.99 mg/g), while M presents (3.31 mg/g) coumarylic anthocyanin levels higher than CS (1.99 mg/g). The study concerning wine tannin quality, was conducted for 24 vintages for CS and for 7 vintages for M. Total phenolic compounds, total anthocyanins, total tannins, tannin monomers (C+EC), hue, IC' (color intensity), % G, % P, mDP and astringency intensity differentiate wines according to vintage. The correlation between wine age and: mDP, hue, astringency, total phenolic compounds, tannin monomers (C+EC) and total tannin levels are obtained. The qualitative tannin and wine characterization is established by correlation between astringency and mDP (R 2 = 0.509, p = 0.051, CS; R2= 0.780, p = 0.000, M). In addition, the mDP appears to be vintage marker (R 2 = 0.796, p = 0.000; CS and R2 = 0.946, p = 0.000; M). Scale patterns between wine mDP and both ageing and tannin perception (astringency) are proposed. M wines are characterized by lower levels of total phenolic compounds, tannins, anthocyanins, mDP, % G, % P % levels as well as by lower astringency intensity than CS wines. Ethanol level seems to be positively correlated to bitterness (r = 0.39, p < 0.05).

Les flavanols et leurs oligomères, les procyanidines, sont des composés phénoliques biosynthétisés dans les baies de raisin, dont ils sont extraits pendant la vinification. Une meilleure compréhension de leur évolution pendant la maturation du raisin, la vinification et le vieillissement du vin est importante du fait de leur responsabilité dans beaucoup des propriétés organoleptiques du vin (couleur, amertume et astringence). Plusieurs procyanidines ont été obtenues par une méthode de synthèse permettant de contrôler aussi bien la régio- et la stéréosélectivité de la liaison interflavane que le degré d’oligomérisation. Cette méthode a pu être élargie à la synthèse de procyanidines galloylées. L’étape de couplage, qui restait l’étape limitante de cette synthèse, a pu être améliorée par l’utilisation de la catalyse à l’or. Ces composés ont ensuite été utilisés comme standards afin de les identifier et les quantifier dans du raisin et des vins par chromatographie liquide haute performance. L’étude des intéractions supramoléculaires des composés galloylés a été évaluée par RMN DOSY. En parallèle de ces études, un nouveau composé indolique, possédant un motif glucose dans sa structure, a été identifié et caractérisé pour la première fois dans les vins rouges. / Flavanols and their oligomers, procyanidins, are phenolics compounds biosynthetized in grapes, from which they are extrated during winemaking As they contribute so much to the organoleptics properties of the wine (color, bitterness and astringency), a better comprehension of their evolution during grapes maturation, winemaking and ageing of the wine is particulary important. Several procyanidines were obtained by a synthesis method which allows to control as well the interflavan regio- and stereoselectivity as the degree of oligomerization. This method was extended to the synthesis of galloylated procyanidins. The stage of coupling, which was a limiting stage of this synthesis, could be improved by the use of gold III catalysis. These compounds were then used as standards in order to identify and quantify them in grapes and wines by high performance liquid chromatography. The supramolecular properties of galloylated procyanidins were investigated by NMR DOSY. In parallel to these studies, a new indolic compound bearing a glucose moiety, has been identified and characterized for the first time in red wine.

La réduction des effets secondaires des produits phytosanitaires sur l’environnement est un enjeux majeur du Grenelle de l’environnement. L’utilisation prolongée du cuivre comme fongicide a entrainé son accumulation dans les sols viticoles. Le cuivre étant phytotoxique,son accumulation dans la plante pourrait modifier la morphologie, la biochimie ou la physiologie des organes végétaux et perturber les interactions vigne-bio-agresseur. Nousavons donc évalué les effets de la contamination cuprique des sols viticoles sur la sensibilitéde la vigne à un cortège de bio-agresseurs par une approche plus intégrée de la culture et deson patho-système.Pour cela, nous avons mesuré les teneurs en cuivre total et disponible des parcelles viticoles.Nous avons exposé au cuivre trois cépages puis nous avons mesuré la distribution du cuivre et ses effets dans la plante. Enfin nous avons évalué l’impact induit pour trois bio-agresseurs de la vigne. Nos résultats montrent que la teneur en cuivre disponible du sol dépend surtout de la teneur total en cuivre (qui résulte de l’historique parcellaire) mais aussi des teneurs en carbone total et en particules fines du sol. L’absorption du cuivre et son transfert vers les parties aériennes varient selon les cépages. Lorsque la contamination cuprique augmente, les interactions vigne-bio-agresseurs sont modifiées : si les effets semblent négatifs pourScaphoideus titanus et Plasmopara viticola, la contamination cuprique semble favorable au développement de Neofusicoccum Parvum. Ces résultats soulignent la nécessité d’avoir une vision la plus intégrée possible du système, et d’intensifier les interactions de recherches entre l’agronomie et l’écologie évolutive. / Following the ‘Grenelle of the environment’ conference, one of the current critical issues in agriculture is reducing the side effects of pesticides on the environment. Prolonged use of copper as a fungicide has led to copper accumulation in vineyard soils. Copper can induce aphytotoxicity. Its accumulation in plants may modify the morphology, biochemistry orphysiology of plant organs and may disturb the plant-pest interactions. The effects of coppercontamination of vineyard soils on the vine sensitivity to the pests received until now a verylimited attention. The present work investigates such effects.To carry out this work, we measured the levels of total and available copper in vineyard soils.We contaminated three grapevine cultivars with copper and measured the copper distributionand its effects on plant. Then, we evaluated the impact induced on three pests of the vine. Ourresults show that the available copper content in the soil is related to the total copper content(which results from the history of the plot), but also to total carbon and fine soil particlescontents. The copper absorption and the copper transferred to the aerial parts of the vine varyaccording to the cultivar. When copper contamination increases, the vine-pests interactionsare modified: a negative effects appears for Scaphoideus titanus and Plasmopara viticola,while important copper contaminations appears to promote the development ofNeofusicoccum parvum.These results underscore the need for a more integrated system approach, and to intensifyinteractions between agronomy and evolutionary ecology research.

Molybdenum experiments: In Australia young Merlot vines sometimes suffer from vegetative disorders such as slow, zigzagged growth and leaf distortion. Merlot is also particularly known as a low- and inconsistent-yielding grape variety. Previous research showed that when foliar applications of molybdenum (Mo) were applied to Merlot vines the vegetative symptoms improved. More recently, when sodium molybdate was applied to Mo-deficient Merlot, yield improved; a function of increased bunch weight brought about by bigger berries. It has also been reported that at high concentrations, molybdenum might be detrimental to yield. Experiments were conducted on own-rooted Merlot (clone D3V14) vines in commercial vineyards in the Adelaide Hills (Hills) and at McLaren Vale, South Australia. Effects of molybdenum deficiency on the vegetative growth and yield of Vitis vinifera cv. Merlot: The aims of the current study were to: a) elucidate the mechanism by which molybdenum affects yield of Merlot; b) to monitor the effects of Mo-treatment on the balance between vine reproductive and vegetative growth; c) to monitor the residual effects of Mo-treatment on growth and yield of Merlot and; d) to determine whether high concentrations of molybdenum are detrimental to yield. Three rates of sodium molybdate were applied to vines in springtime (control = 0g, rate 1 = 0.101g and rate 2 = 0.202g sodium molybdate per vine). Vine molybdenum status was measured prior to treatment and again at flowering time using petiole, shoot tip and inflorescence analysis. The effects on vegetative growth were monitored at veraison, during dormancy and at budburst in the seasons following Mo-treatment. At flowering time, pollen vitality, pollen tube growth and flower structure were examined. Bunch number per vine, fruitset, berry weight and berry composition were measured at harvest. In the Hills, the controls had adequate molybdenum however, at McLaren Vale petiolar molybdenum concentration fell within the suggested deficiency range of 0.05-0.09 mg/kg in the petioles at flowering time. No visual symptoms of Mo-deficiency were observed on the experimental vines. At McLaren Vale, Mo-treatment reduced pruning weight and improved vine balance. Mo-treated vines in the Hills and at McLaren Vale were affected by delayed budburst in the season following Mo-treatment irrespective of their Mo-status. However, no seasonal carryover of molybdenum could be detected in tissue analysis at flowering time. Juice total soluble solids, pH and titratable acidity were not affected by Mo-treatment at McLaren Vale or in the Hills. However, juice from Mo-treated vines in the Hills had a significantly higher concentration of molybdenum than the controls. At McLaren Vale there was no significant difference in juice molybdenum concentration between treatments. In the Hills, yield was not affected by Mo-treatment. However, Mo-treated vines at McLaren Vale had significantly higher yields (approximately double) than the Mo-deficient controls. Bunch number per vine was not affected by Mo-treatment, either in the year that treatments were applied or in the following season. However, bunches from Mo-treated vines had significantly better fruitset resulting in more berries per bunch. Berry weight was affected by Mo-treatment in one season only. Yield was not detrimentally affected on vines that received the higher rate of sodium molybdate. In the Hills, Mo-treatment did not affect pollen numbers, pollen vitality or pollen tube growth. At McLaren Vale, where the controls were Mo-deficient, pollen vitality was not affected by Mo-treatment. However, pollen tube growth was significantly enhanced by Mo-treatment. Significantly more pollen tubes penetrated the ovules from Mo-treated vines and a higher proportion of ovaries had at least one penetrated ovule. Structural observations revealed that a significantly higher proportion of ovules from Mo-deficient vines were defective. The absence of an embryo sac in those ovules is probably the cause of pollen tube growth inhibition and subsequent poor fruitset. Effects of mode of pollination on yield of Merlot and the interacting effects of sodium molybdate sprays: Pollination experiments were conducted on field-grown own-rooted Merlot (clone D3V14) vines in commercial vineyards in the Adelaide Hills and at McLaren Vale in 2003-04 and in 2004-05. Inflorescences were supplied with supplementary Merlot pollen (self-pollination), with pollen from another variety (cross-pollination) or they were left to pollinate naturally (open pollination). In the Hills, mode of pollination did not affect fruitset or berry weight. In 2003-04 fruitset increased significantly at McLaren Vale when inflorescences were cross-pollinated with Semillon. Applying supplementary Merlot pollen also tended to improve fruitset, however none of the treatments affected berry weight. In 2004-05 there was no significant difference between treatments. These results indicate that Merlot may be a poor producer of pollen and may suffer from self-incompatibility. Given the significant improvements in yield gained by spring foliar applications of sodium molybdate to Mo-deficient Merlot vines, in 2005-06 a reciprocal experiment was conducted to separate the effects of Mo-treatment and mode of pollination on the male and female flower parts. The aims of this experiment were to: a) determine whether the male or female reproductive organs are more important in determining the success of fruitset of Merlot and; b) determine which remedial measure, Mo-treatment or pollination, is more effective at overcoming poor fruitset. Supplementary pollination treatments—cross-pollination (Semillon); self-pollination (Mo-deficient pollen); self-pollination (Mo-treated pollen) and; open-pollination—were applied to Mo-treated and Mo-deficient vines. Cross-pollinating Mo-deficient vines with Semillon significantly improved fruitset of Merlot compared to other pollination treatments on those vines, however applying molybdenum to the vines in springtime was more effective at improving fruitset. Within the Mo-treated vines the effects of supplementary pollination on fruitset were not thought to be of any practical significance. The results of this experiment provide further evidence that Mo-deficiency affects the female flower parts more than the male reproductive organs of Merlot. The occurrence of ‘star’ flowers in Australia: In 2003 faulty flowers were discovered on Canada Muscat grown in the Coombe Vineyard at the University of Adelaide’s Waite Campus. The Canada Muscat flowers opened from the top in ‘star’ formation in contrast to normal grape flowers, which shed the calyptra from its base. Star flowers were reported in French literature in the late 1800s. They were reported to as a symptom of a ‘disease’ that caused ‘coulure’, the cure for which was vine removal. The current report is the first known report of star flowers occurring in Australia. Through dissemination of the news of this discovery, several star flower variants were found in other varieties in South Australia. The association of star flowers with poor berry development and the frequency of the occurrence of star flowers suggest that this flower aberration may be affecting yield to a greater extent than previously recognised. This study provides a detailed description of two types of star flowers: those that occur in response to environmental conditions and those that occur every season. Other star flower variants are also documented. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1280856 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2007

Molybdenum experiments: In Australia young Merlot vines sometimes suffer from vegetative disorders such as slow, zigzagged growth and leaf distortion. Merlot is also particularly known as a low- and inconsistent-yielding grape variety. Previous research showed that when foliar applications of molybdenum (Mo) were applied to Merlot vines the vegetative symptoms improved. More recently, when sodium molybdate was applied to Mo-deficient Merlot, yield improved; a function of increased bunch weight brought about by bigger berries. It has also been reported that at high concentrations, molybdenum might be detrimental to yield. Experiments were conducted on own-rooted Merlot (clone D3V14) vines in commercial vineyards in the Adelaide Hills (Hills) and at McLaren Vale, South Australia. Effects of molybdenum deficiency on the vegetative growth and yield of Vitis vinifera cv. Merlot: The aims of the current study were to: a) elucidate the mechanism by which molybdenum affects yield of Merlot; b) to monitor the effects of Mo-treatment on the balance between vine reproductive and vegetative growth; c) to monitor the residual effects of Mo-treatment on growth and yield of Merlot and; d) to determine whether high concentrations of molybdenum are detrimental to yield. Three rates of sodium molybdate were applied to vines in springtime (control = 0g, rate 1 = 0.101g and rate 2 = 0.202g sodium molybdate per vine). Vine molybdenum status was measured prior to treatment and again at flowering time using petiole, shoot tip and inflorescence analysis. The effects on vegetative growth were monitored at veraison, during dormancy and at budburst in the seasons following Mo-treatment. At flowering time, pollen vitality, pollen tube growth and flower structure were examined. Bunch number per vine, fruitset, berry weight and berry composition were measured at harvest. In the Hills, the controls had adequate molybdenum however, at McLaren Vale petiolar molybdenum concentration fell within the suggested deficiency range of 0.05-0.09 mg/kg in the petioles at flowering time. No visual symptoms of Mo-deficiency were observed on the experimental vines. At McLaren Vale, Mo-treatment reduced pruning weight and improved vine balance. Mo-treated vines in the Hills and at McLaren Vale were affected by delayed budburst in the season following Mo-treatment irrespective of their Mo-status. However, no seasonal carryover of molybdenum could be detected in tissue analysis at flowering time. Juice total soluble solids, pH and titratable acidity were not affected by Mo-treatment at McLaren Vale or in the Hills. However, juice from Mo-treated vines in the Hills had a significantly higher concentration of molybdenum than the controls. At McLaren Vale there was no significant difference in juice molybdenum concentration between treatments. In the Hills, yield was not affected by Mo-treatment. However, Mo-treated vines at McLaren Vale had significantly higher yields (approximately double) than the Mo-deficient controls. Bunch number per vine was not affected by Mo-treatment, either in the year that treatments were applied or in the following season. However, bunches from Mo-treated vines had significantly better fruitset resulting in more berries per bunch. Berry weight was affected by Mo-treatment in one season only. Yield was not detrimentally affected on vines that received the higher rate of sodium molybdate. In the Hills, Mo-treatment did not affect pollen numbers, pollen vitality or pollen tube growth. At McLaren Vale, where the controls were Mo-deficient, pollen vitality was not affected by Mo-treatment. However, pollen tube growth was significantly enhanced by Mo-treatment. Significantly more pollen tubes penetrated the ovules from Mo-treated vines and a higher proportion of ovaries had at least one penetrated ovule. Structural observations revealed that a significantly higher proportion of ovules from Mo-deficient vines were defective. The absence of an embryo sac in those ovules is probably the cause of pollen tube growth inhibition and subsequent poor fruitset. Effects of mode of pollination on yield of Merlot and the interacting effects of sodium molybdate sprays: Pollination experiments were conducted on field-grown own-rooted Merlot (clone D3V14) vines in commercial vineyards in the Adelaide Hills and at McLaren Vale in 2003-04 and in 2004-05. Inflorescences were supplied with supplementary Merlot pollen (self-pollination), with pollen from another variety (cross-pollination) or they were left to pollinate naturally (open pollination). In the Hills, mode of pollination did not affect fruitset or berry weight. In 2003-04 fruitset increased significantly at McLaren Vale when inflorescences were cross-pollinated with Semillon. Applying supplementary Merlot pollen also tended to improve fruitset, however none of the treatments affected berry weight. In 2004-05 there was no significant difference between treatments. These results indicate that Merlot may be a poor producer of pollen and may suffer from self-incompatibility. Given the significant improvements in yield gained by spring foliar applications of sodium molybdate to Mo-deficient Merlot vines, in 2005-06 a reciprocal experiment was conducted to separate the effects of Mo-treatment and mode of pollination on the male and female flower parts. The aims of this experiment were to: a) determine whether the male or female reproductive organs are more important in determining the success of fruitset of Merlot and; b) determine which remedial measure, Mo-treatment or pollination, is more effective at overcoming poor fruitset. Supplementary pollination treatments—cross-pollination (Semillon); self-pollination (Mo-deficient pollen); self-pollination (Mo-treated pollen) and; open-pollination—were applied to Mo-treated and Mo-deficient vines. Cross-pollinating Mo-deficient vines with Semillon significantly improved fruitset of Merlot compared to other pollination treatments on those vines, however applying molybdenum to the vines in springtime was more effective at improving fruitset. Within the Mo-treated vines the effects of supplementary pollination on fruitset were not thought to be of any practical significance. The results of this experiment provide further evidence that Mo-deficiency affects the female flower parts more than the male reproductive organs of Merlot. The occurrence of ‘star’ flowers in Australia: In 2003 faulty flowers were discovered on Canada Muscat grown in the Coombe Vineyard at the University of Adelaide’s Waite Campus. The Canada Muscat flowers opened from the top in ‘star’ formation in contrast to normal grape flowers, which shed the calyptra from its base. Star flowers were reported in French literature in the late 1800s. They were reported to as a symptom of a ‘disease’ that caused ‘coulure’, the cure for which was vine removal. The current report is the first known report of star flowers occurring in Australia. Through dissemination of the news of this discovery, several star flower variants were found in other varieties in South Australia. The association of star flowers with poor berry development and the frequency of the occurrence of star flowers suggest that this flower aberration may be affecting yield to a greater extent than previously recognised. This study provides a detailed description of two types of star flowers: those that occur in response to environmental conditions and those that occur every season. Other star flower variants are also documented. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1280856 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2007

Neste trabalho foram estudados vinhos provenientes de microvinificações das variedades Merlot e Cabernet Sauvignon das sub-regiões de Pinto Bandeira, Vale dos Vinhedos, Nova Pádua e Monte Belo do Sul, nas safras de 2005 e 2006. Foram determinadas as razões isotópicas 13C/12C do etanol e 18O/16O da água e do etanol, buscando possível diferenciação entre as variedades e safras de produção, e provável relação entre o local de origem e suas características geográficas (altitude e latitude) e climatológicas (temperatura, precipitação pluviométrica e umidade). Utilizou-se um espectrômetro de massas de razão isotópica (IRMS) acoplado a um analisador elementar, para análise de 13C/12C do etanol e 18O/16O da água e a um cromatógrafo gasoso, para análise de 18O/16O do etanol. Em relação aos valores de δ13C, observou-se que a diferenciação entre as sub-regiões amostrais são menos seletivas e não seguem mesma ordem estatística encontrada para as análises δ18O, porém a análise de δ13C do etanol pode servir para diferenciar sub-regiões que não são diferenciadas estatisticamente pelas análises de δ18O. O comportamento dos valores de δ18O da água e do etanol obedecem mesma ordem estatística de diferenciação. Independente da variedade de uva utilizada neste trabalho, foi possível diferenciar as sub-regiões através da análise isotópica de δ18O, nas duas safras de produção, com exceção do Vale dos Vinhedos e Monte Belo do Sul, safra 2005, que não apresentaram diferenças estatísticas. As latitudes das diferentes sub-regiões apresentaram diferença estatística e demonstraram influência principalmente nos valores de δ18O da água. As análises de δ18O da água e do etanol do vinho mostraram-se mais seletivas e eficientes na discriminação das sub-regiões de cultivo do que as análises de δ13C do etanol. Foi observada uma forte correlação entre os valores de δ18O da água e do etanol. A altitude e a latitude influenciam principalmente os valores de δ18O da água e do etanol. As influências climáticas são mais marcantes na distinção entre safras de produção do que sub-regiões de cultivo. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-05-14T18:11:59Z No. of bitstreams: 1 Dissertacao Laurien Adami.pdf: 946622 bytes, checksum: 1405d2dd9ccbcd048e59ac45e36fd0f7 (MD5) / Made available in DSpace on 2014-05-14T18:11:59Z (GMT). No. of bitstreams: 1 Dissertacao Laurien Adami.pdf: 946622 bytes, checksum: 1405d2dd9ccbcd048e59ac45e36fd0f7 (MD5) / In this work, wines provided by micro-winemakings of the variety Merlot and Cabernet Sauvignon of the sub-regions of Pinto Bandeira, Vale dos Vinhedos, Nova Pádua and Monte Belo do Sul in the 2005 and 2006 harvest have been studied. It has been established the isotopic ratios 13C/12C of the ethanol and 18O/16O of the water and ethanol, seeking for a possible differentiation among the varieties and production harvests, and a possible relation between the place of origin and its geographic features (altitude and latitude) and climatological conditions (temperature, precipitation and humidity). It has been used a isotope ratio mass spectrometer (IRMS) coupled to an elementar analyzer for the analysis of the 13C/12C of the ethanol and 18O/16O of the water and to a gas chromatograph for the analysis of 18O/16O of the ethanol. In relation to the values of δ13C, it is observed that the differentiation among the sampling sub-regions are less selective and do not follow the same statistical order found for the analysis of δ18O, however, the analysis of δ13C of the ethanol may be used to differentiate sub-regions that are not differentiated statistically by the analysis of δ18O. The value behaviors of δ18O of the water and the ethanol follow the same statistical order of differentiation. Regardless of the grape variety used in this work, it has been possible to differentiate the sub-regions through the isotopic analysis of the δ18O, in both production harvests, except for the Vale dos Vinhedos and Monte Belo do Sul, 2005 harvest, which did not present statistical differences. The latitudes of the different sub-regions presented statistical differences and demonstrated an influence mainly in the values of δ18O of the water. The analysis of δ18O of the water and the ethanol of the wine conveyed to be more selective and efficient in the discrimination of the cultivation sub-regions than the analysis of δ13C of the ethanol. It has been observed a strong correlation between the values of δ18O of the water and the ethanol. The altitude and latitude influence mainly the values of δ18O of the water and the ethanol. The climate influences are more noteworthy in distinguishing the production harvests than the cultivation sub-regions.