@phdthesis{Adler2025, author = {Adler, Katharina}, title = {Avian diversity in vineyards - Circannual effects of landscape structure and management practices in viticultural regions}, volume = {2025}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-1167}, school = {Hochschule Geisenheim University}, pages = {1 -- 148}, year = {2025}, abstract = {Methods of intensive land use and structural impoverishment of landscapes have been shown to have a strong negative impact on biodiversity in agricultural landscapes. Due to increasing population numbers and growing yield demands on less land, the sustainable management of utilised biotope types in agricultural landscapes has become a key topic of biodiversity research. More than any other bird species group, birds of the agricultural landscape have experienced massive population declines throughout Germany and Europe in recent years. The majority of research projects carried out in this area relate to annual crops. However, permanent crops, such as fruit plantation, vineyards and timber plantations, have received little attention in biodiversity research to date. Due to ongoing climate change, vineyards will also become increasingly important outside the Mediterranean region, replacing more and more semi-natural habitats. This makes it all the more important to understand how these cultures affect biodiversity and how this can be sustainably managed. Wine-growing areas offer potentially attractive living conditions for avifauna: The wooden structures of the vines, greening between the rows of vines and a mosaic with neighbouring unused structures can provide suitable habitat structures for different species. In many cases, however, viticulture is characterised by intensive management regimes with frequent disturbance events such as pesticide application, tillage or mowing of the species-poor green alleys and removal of marginal structures. Various studies show that these factors in crop monocultures have a major influence on bird diversity. The aim of this thesis was to analyse the influence of different landscape structures on the bird community in wine-growing areas and the influence of these bird communities on viticulture in terms of grape damage. The following studies were carried out for this purpose: -A literature study on the main influencing factors already identified in the scientific literature was compiled for both topics. -Two wine-growing regions in Germany (Rheingau and Rheinhessen) were analysed in a case study. Bird species were recorded throughout 2020 and 2021 and then analysed with data on the composition and structure of the landscape, which were collected by digitising orthophotos and verifying them on site. -In a further field study in Napa Valley (CA, USA), grape damage caused by birds in six vineyards was recorded and analysed with data from the landscape as well as vineyard management to determine which structures made grapes particularly enticing as food for birds.}, language = {en} } @phdthesis{Lamberty2025, author = {Lamberty, Anna}, title = {Development of a generic concept for cross chain temperature monitoring using IoT-based sensor technology to optimize the product quality of fresh plant-based produce}, volume = {2025}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-1189}, school = {Hochschule Geisenheim University}, pages = {II -- 184}, year = {2025}, abstract = {The objective of this thesis was to develop a generic implementation concept for cross-chain IoT-based temperature monitoring in supply chains of fresh plant-based produce, including a cost-benefit-assessment. In the first step, a literature review was conducted to categorize fresh fruit and vegetables by their product-specific spoilage kinetics in relation to the main influential ambient parameters (temperature, relative humidity, ethylene, CO2, O2, vibration). In addition, the state-of-theart of relevant IoT technology was reviewed. This was followed by a systematic literature review and practical tests in four supply chains, focusing on data transmission reliability, temperature accuracy, location accuracy, battery life and sustainability, to identify technical, process-related and sustainability requirements for IoT-based temperature monitoring systems. Based on those results and a multi-dimensional field analysis including stakeholder interviews, a generic implementation concept was elaborated and validated in a real-world pilot study. Finally, the results of stakeholder interviews were used to create three application scenarios for IoT-based temperature monitoring. The costs and benefits of an IoT implementation were assessed for each scenario. The results highlight the complexity of fresh plant-based produce but also show the potential for optimizing product qualities by using IoT-based temperature monitoring, particularly for berries, leafy vegetables, climacteric fruit and chilling-sensitive products. While suitable IoT technology is available, the variety can make it challenging for supply chain actors to choose the right solution. Here, the identified technical, process-related and sustainability requirements can aid decision-making for potential users and provide development insights for IoT providers. However, needs for improvements of the tested IoT systems were found, particularly regarding data transmission reliability, temperature accuracy and sensor sustainability. The developed generic concept provides a blueprint for practical implementation in supply chains. The validation results confirm its operational feasibility. Further, it was found that IoT-based temperature monitoring can lead to monetary savings by reducing product losses, depending on the specific combination of IoT technology, product, packaging type, data use, and hardware reuse frequency. It must be highlighted that sustainable use of IoT devices enhances potential monetary benefits by avoiding subsequent sensor purchase costs.}, language = {en} } @phdthesis{DELONGHI2024, author = {DE LONGHI, Emilio}, title = {Sensory and chemical characterization of the aroma of Riesling wines}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-1121}, school = {Hochschule Geisenheim University}, pages = {i -- XXIX}, year = {2024}, abstract = {Riesling wines are appreciated for their diverse and distinctive aromas, resulting from complex interactions of their numerous volatile components with human olfactory system. However, the volatile composition associated with the aroma properties of Riesling wines has not been fully understood. The aim of this thesis was to advance the characterization of Riesling wine volatile composition, through analytical and sensory approaches. Focusing on the thiol component of Riesling wine, sensory-guided screening by heart-cutting multidimensional gas chromatography mass spectrometry/olfactometry (H/C MDGC-MS/O) of Riesling wine thiol selective extracts, obtained by Ag+ solid-phase extraction (Ag+ SPE), followed by Riesling wine thiol analysis by ultra high-performance liquid chromatography (UHPLC) quadrupole Orbitrap high-resolution mass spectrometry (HRMS) in parallel reaction monitoring (PRM), enabled the identification of twelve volatile odorant thiol candidates in Riesling wine (3-sulfanylhexan-1-ol, 3-sulfanylheptan-1-ol, 3-sulfanylhexyl acetate, 4-methyl- 4-sulfanylpentan-2-one, ethyl 3-sulfanylpropionate, ethyl 2-sulfanylpropionate, trans-2- methyl-3-tetrahydrofuranthiol, 2-methyl-3-furanthiol, benzenemethanethiol, o-toluenethiol, mtoluenethiol, and 2-furfurylthiol). LC-MS analysis empowered to quantify the twelve thiols in a set of Riesling wines (n = 33), highlighting their occurrence at concentrations reaching sensory detection threshold values. Additionally, it allowed the detection of two new monoterpenoid thiols 1-p-menthene-8-thiol and trans-p-menthane-3-one-8-thiol in wine for the first time, two compounds possessing respectively grapefruit and blackcurrant aroma nuances. The odor thresholds of these thiols in model wine were determined at 0.076 ng/L and 22.9 ng/L, respectively. The employed LC-MS analytical method was newly developed for the quantitation of ultra-trace volatile thiols in wine. The proposed procedure, consisting of thiol derivatization by 4,4'-dithiodipyridine (DTDP), followed by thiol-DTDP derivatives isolation by liquid-liquid extraction, allowed rapid sample preparation. Instrument analysis performed using UHPLC quadrupole Orbitrap HRMS offered ultra-selectivity and sensitivity for 19 selected thiols. The analytical performances of the novel method were observed in most cases greater than those of previously developed methods. A comprehensive investigation of the links between volatile composition and sensory properties of Riesling wine was then conducted, combining sensory descriptive analysis with quantitative chemical data from a selection of Riesling wines from Germany and France (n = 27). The results from the quantitative chemical analysis of 77 volatile compounds and 14 basic wine parameters were merged with the sensory scores obtained from the descriptive analysis of the collected wine samples by a German-based experienced panel (n = 18) through partial least squares (PLS) regression. The analyzed volatiles spanned from different molecular families known for their relevance for Riesling wine aroma and included monoterpenes, C13-norisoprenoids, higher alcohols, acetate esters, fatty acid ethyl esters, lactones, light volatile sulfur compounds, and polyfunctional thiols. Selected compounds with higher regression coefficients in relation to Riesling aromatic typicality scoring were supplemented in Riesling wine, up to concentration levels reached by the most typical ranked wines, and were found to be associated with a significant increase of Riesling olfactory typicality perceived by experienced sensory judges (n = 15). Overall, this work has advanced the knowledge about molecular drivers of aroma perception of Riesling wines, pointing out the role of novel potent polyfunctional thiols, in association to other major aroma components of Riesling wines. These findings offer promising prospects for the winemaking industry and for future advancements in Riesling wine aroma research.}, language = {en} } @phdthesis{Hauck2024, author = {Hauck, Katharina}, title = {Challenges of the organic wine sector - A value chain analysis of organic wine in Germany}, volume = {2024}, number = {99}, edition = {1. Auflage}, publisher = {Geisenheimer Berichte}, address = {Geisenheim}, isbn = {ISBN 978 3 934742 91 8}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-898}, school = {Hochschule Geisenheim University}, pages = {II -- 95}, year = {2024}, abstract = {The demand for organic products is continuously increasing, with Germany's organic market reaching 15.9 billion euros, making it the second largest in the world. Concurrently, the organically farmed area in Germany is also expanding. The German wine industry is similarly affected, with the share of organic viticulture more than doubling over the past decade. However, there is a notable disparity in the demand for organic wine compared to other organic foods. This dissertation aims to explain the discrepancy between the increasing area of organically cultivated vineyards and the lack of conscious purchasing of organic wine. The research project investigates the entire value chain of organic wine using qualitative and quantitative methods. It surveys producers about their attitudes and motivations behind converting vineyards to organic farming, and includes feedback from traders to define consumer preferences and future market developments. The study also examines the end consumer's perspective to understand why organic wine is not consciously perceived and purchased. The findings reveal that personal conviction drives winegrowers to switch to or maintain organic farming, but low demand is offset by challenging production conditions and higher costs. Traders are interested in organic wine only if there is demand, and their limited knowledge hinders consumer education.}, language = {de} } @phdthesis{Fackert2024, author = {Fackert, Marcel Monti}, title = {Analyse und Gestaltung der Logistikprozesse in der deutschen Qualit{\"a}tsschaumweinindustrie unter besonderer Ber{\"u}cksichtigung von Digitalisierung und Automatisierung}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-1131}, school = {Hochschule Geisenheim University}, pages = {I -- 230}, year = {2024}, abstract = {Diese Dissertation untersucht die logistischen Zusammenh{\"a}nge in den Wertsch{\"o}pfungsstufen der Qualit{\"a}tsschaumweinindustrie in Deutschland. Der Absatz und die Herstellung von Qualit{\"a}tsschaumwein ist im Betrachtungs-zeitraum von 2002 bis heute stetig gestiegen und hat sich im Volumensegment bereits auf wenige große Hersteller konsolidiert. Die Marktstruktur und -teil-nehmer werden aufgezeigt und ihre Motivation hinsichtlich Umsatz, Menge und Herstellqualit{\"a}t genau beschrieben. Die neu entwickelte Sekt Supply Chain visualisiert die verschiedenen logistischen Wertsch{\"o}pfungsketten von der Traube bis zum fertigen Sekt {\"u}ber die Schritte des eigenen Anbaus bzw. dem Zukauf von Rohstoffen, den verschiedenen Herstellungsverfahren und Lagerhaltungsm{\"o}glichkeiten bis hin zur Distribution. Durch explorative Experteninterviews werden logistische Trends in der Digitalisierung, Automatisierung und Nachhaltigkeit f{\"u}r die Branche bewertet. Digitalisierung findet zwar in fast allen Unternehmen statt, jedoch mit unterschiedlichen Ans{\"a}tzen. F{\"u}r alle gemein ist die effizientere Herstellung auf Basis von Echtzeitdaten und Reduzierung der Durchlaufzeiten und Losgr{\"o}ßen f{\"u}r schnellere Reaktionszeiten mit weniger Best{\"a}nden. Die Sekthersteller kommen digital n{\"a}her an den Kunden und produzieren bedarfsgenauer. Bei Sektmanufakturen ist durchg{\"a}ngig ein gesteigertes Qualit{\"a}tsniveau festzustellen, wobei traditionelle Methoden nicht im Widerspruch zur Automatisierung von Prozessschritten zur Steigerung der Flexibilit{\"a}t und Reduzierung von Kapazit{\"a}tskosten wie Personaleinsatz stehen. In der Sekt Supply Chain gibt es in den einzelnen Logistikprozessen viel Optimierungspotential. Dies wird mit zwei Detailbeispielen, der Reduzierung von Verschwendung bei der schlanken Traubenanlieferung des Badischen Winzerkellers und bei der bedarfs- bzw. bestandsoptimierten Prognose bei Rotk{\"a}ppchen-Mumm mit Hilfe des Advanced Planning mit einer daf{\"u}r entwickelten mathematischen Formel aufgezeigt. Trotz aller unternehmensspezifischer Unterschiede und der Heterogenit{\"a}t des deutschen Sektmarktes gibt es doch Gemeinsamkeiten in den logistischen Prozessen unter dem Einfluss der Digitalisierung und Automatisierung.}, language = {de} } @phdthesis{Dahlmann2024, author = {Dahlmann, Melanie}, title = {Entwicklung eines innovativen Fallendesigns f{\"u}r ein Attract-and-Kill Verfahren zur nachhaltigen Bek{\"a}mpfung der Kirschessigfliege Drosophila suzukii im Obst- und Weinbau}, volume = {2025}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-1077}, school = {Hochschule Geisenheim University}, pages = {436}, year = {2024}, abstract = {Seit 2008 verursacht die Kirschessigfliege Drosophila suzukii (MATSUMURA 1931) (Diptera: Drosophilidae) aufgrund ihrer polyphagen Lebensweise nicht nur in Europa hohe wirtschaft-liche Verluste vor allem im Stein- und Beerenobstanbau, aber auch im Weinbau. Die invasive Art hat sich weltweit rasant ausgebreitet, vor allem {\"u}ber den Export von Fr{\"u}chten. Eine hohe Vermehrungsrate und die Anpassung an klimatische Bedingungen machen diesen Sch{\"a}dling zu einem ernsthaften Problem f{\"u}r den Pflanzenschutz in Obst- und Weinbaugebieten. Im Gegensatz zu monophag lebenden Schaderregern, stellt die polyphage Lebensweise der Kirschessigfliege eine weitere Herausforderung f{\"u}r eine gezielte und nachhaltige Bek{\"a}mpfung dar. F{\"u}r eine fr{\"u}hzeitige Prognose von Schadschwellen und eine effiziente Bek{\"a}mpfung von D. suzukii, z. B. durch den Einsatz von Insektiziden, ist daher die Kenntnis {\"u}ber biologische Verhaltensparameter sowie {\"U}berwinterungs- und R{\"u}ckzugsgebiete, aus denen der Schadorga-nismus in die Obst- und Weinberge migriert, von großer Bedeutung. In Deutschland wurden bereits mehr als 50 Wirtspflanzen aus Kultur- und Wildpflanzen als Vermehrungshabitat identifiziert. Aufgrund des anhaltenden Mangels an alternativen Methoden zur Bek{\"a}mpfung von D. suzukii, ist auch das Wissen um die Wirksamkeit von Insektiziden entscheidend f{\"u}r ein optimal angepasstes Bek{\"a}mpfungsmanagement. Ziel der vorliegenden Dissertation war es, visuelle und olfaktorische Lockmittel f{\"u}r eine nachhaltige und umweltfreundliche Bek{\"a}mpfungsstrategie gegen Drosophila suzukii zu ent-wickeln, die auf der Methode des Attract-and-Kill (engl. Anlocken-und-Abt{\"o}ten) Verfahrens basiert. Der Schwerpunkt lag auf der Entwicklung eines geeigneten Fallendesigns und eines attraktiven K{\"o}ders, welcher in Kombination mit einem (biologischen) insektiziden Wirkstoff als Fraßk{\"o}der in Fangfallen oder zur Blattapplikation verwendet werden k{\"o}nnte. Die Kombi-nation aus Lockstoff und Insektizid soll dazu beitragen, den Einsatz von Pflanzenschutz-mitteln zu reduzieren und die Vermehrungsrate von D. suzukii nachhaltig zu senken. Im Rahmen der vorliegenden Dissertation ist es gelungen, ein Fallendesign zu entwickeln, das insbesondere f{\"u}r Drosophila suzukii Weibchen attraktiv ist. Das Design, welches auf kugel-f{\"o}rmigen Objekten in unterschiedlichen Farben auf rotem Hintergrund basiert, zeigte eine geschlechterspezifische Attraktivit{\"a}t durch eine signifikant h{\"o}here Anzahl weiblicher Indi-viduen im Vergleich zu D. suzukii M{\"a}nnchen innerhalb der Falle. Diese positive Eigenschaft des neuen Fallendesigns wurde in Gew{\"a}chshaus- und Halbfreilandversuchen festgestellt und war ebenfalls unter Freilandbedingungen reproduzierbar. Die Entwicklung eines Fraßk{\"o}ders (Phagostimulans) aus weitestgehend nat{\"u}rlichen Inhaltsstoffen zeigte unter Laborbedingun-gen vielversprechende Ergebnisse f{\"u}r einen m{\"o}glichen Einsatz im Rahmen eines Attract-and-Kill Verfahrens, z. B. als Fraß-, bzw. Eiablagek{\"o}der. Der K{\"o}der zeigte eine hohe Attraktivit{\"a}t im Vergleich zu einer nat{\"u}rlichen Wirtsfrucht (Choice-Test) sowie eine Wirkung auf die Mortalit{\"a}tsrate adulter D. suzukii (M{\"a}nnchen 99 \% und Weibchen 70 \% Mortalit{\"a}t nach 72 h im Vergleich zur unbehandelten Kontrolle). Dar{\"u}ber hinaus konnte ein Einfluss des Fraß-Eiablage-K{\"o}ders auf die larvale Entwicklung und eine Verringerung der Verpuppungsrate nachgewiesen werden. Erg{\"a}nzend zu der Entwicklung m{\"o}glicher Lockstoffe f{\"u}r den Einsatz im Attract-and-Kill Verfahren wurden Laborversuche mit adulten D. suzukii und L1-Larven durchgef{\"u}hrt, um die Wirksamkeit verschiedener Pr{\"u}fsubstanzen auf die Fekundit{\"a}t, Repro-duktionsrate sowie die Mortalit{\"a}t zu untersuchen. Die Versuche mit dem Wirkstoff Azadirachtin A (NeemAzal® technical, NeemAzal®-T/S) zeigten nach oraler Aufnahme einen Effekt auf die Fekundit{\"a}t und auf den Larvenschlupf. Auch die larvale Entwicklung von D. suzukii in einem festen Medium wurde unter dem Einfluss von Azadirachtin A reduziert bzw. verhindert. Ein Einfluss des Wirkstoffes auf die Mortalit{\"a}t adulter Versuchstiere konnte nicht festgestellt werden. Die Verwendung des Pr{\"a}parates SpinTor® (Wirkstoff Spinosad) in Laborversuchen f{\"u}hrte sowohl bei adulten D. suzukii (nach 24 bis 48 h) sowie bei D. suzukii L1-Larven (nach 24 h) bei Kontakt mit einem behandelten Medium zu einer Mortalit{\"a}tsrate von 100 \%. Das Konservierungsmittel Sorbins{\"a}ure, welches als weiteres Pr{\"u}fmittel getestet wurde, zeigte bei Kontakt oder nach oraler Aufnahme keine Wirkung auf die Mortalit{\"a}t adulter D. suzukii. Die orale Aufnahme von Sorbins{\"a}ure f{\"u}hrte jedoch zu einer schwach signifikanten Reduktion der Eiablage und des Larvenschlupfes gegen{\"u}ber der Anzahl Eier und Larven der unbehandelten Kontrolle und zu einer Mortalit{\"a}tsrate von 100 \% bei L1-Larven (nach 24 h), wenn sie einem mit Sorbins{\"a}ure behandelten Medium ausgesetzt waren. Die Ergebnisse aus der vorliegenden Dissertation sollen weitere Forschungsvorhaben unterst{\"u}tzen und dazu beitragen, die Entwicklungen von Fraßk{\"o}dern bzw. K{\"o}der-Insektizid-Mischungen und K{\"o}derstationen f{\"u}r eine effiziente Attract-and-Kill Strategie zur nachhaltigen Bek{\"a}mpfung der Kirschessigfliege Drosophila suzukii zu optimieren.}, language = {de} } @phdthesis{Le2025, author = {Le, Ngoc Duc}, title = {Investigation of the potential allergenicity and coloration of peanut and hazelnut regarding different high-temperature processing methods}, volume = {2025}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-1055}, school = {Hochschule Geisenheim University}, pages = {i -- 259}, year = {2025}, abstract = {Peanut and hazelnut are important sources of protein and are often processed using methods like roasting, baking, frying, and cooking. However, since both are major allergens, it is crucial to study how processing affects their potential to cause allergic reactions. This doctoral research is part of the ErdHase project, which aims to understand the impact of high-temperature processing on the biochemical and physical properties these nuts. The first goal of the study was to determine suitable parameters to define the processing degree of peanuts and hazelnuts, such as L* (lightness) and the browning index (BI). Their reference values, which depend on raw materials and market preferences, were derived based on commercial products and experimental roast models. The study employed various processing methods including drum roasting, infrared roasting, deep frying (for peanut), and fluid-bed roasting (for hazelnut). To study the effects of temperature and time on coloration and moisture, response surface methodology (RSM) was used. This approach was considered effective in reducing the number of experiments needed while maintaining reliable results. As temperature and time increased, the moisture content decreased, and the browning increased, which was consistent with prior research. Additionally, the study found that the ∆E2000 total color difference was more accurate than ∆E76 for assessing the total color difference between processed samples and commercial products. Combining all the collected data, it could be seen that for both Virginia and Runner peanuts and hazelnut, infrared roasting reduced the MC faster and drum roasting affected the color more drastically at the same temperature compared to other approaches. Deep frying of peanut and fluid bed roasting of hazelnut requires higher temperature profiles to achieve a comparable effect. The second part of the research focused on optimizing protein extraction from both raw and processed peanuts and hazelnuts. An extraction protocol using Tris-containing buffer with mild heating was developed and optimized using RSM, yielding good results with minimal denaturation of proteins. The study also showed the protein composition of processed peanuts and hazelnuts using SDS-PAGE and NativePAGE. Processing methods like roasting and frying reduced the protein yield, and allergen bands were detected, although patient-specific IgE binding varied. Further research involved the development of buckwheat-based foods (cream alternative and cookies) to test for the allergenicity in ELISA. Infrared and drum roasting was found to have the greatest impact on allergen recovery. Additionally, a food-grade protease was applied for improving allergen extraction. This enzyme significantly increased allergen recovery without affecting ELISA performance, offering a potential solution to the problem of low extractability of processed allergens. In summary, the presented doctoral thesis, on the one hand, provided additional investigations regarding different high-temperature processing methods on coloration and moisture content of peanut and hazelnut. It confirmed previous observation, defined a new approach of combining L* and BI to evaluate processed products. On the other hand, on the biochemical aspect of processed peanuts and hazelnuts, this work provided an optimized extraction protocol that potentially works for a wide spectrum of processed samples. In addition, incurred buckwheat-based products and enzyme-assisted extraction for ELISA showed promising results for future applications regarding their potential allergenicity.}, language = {en} } @phdthesis{Koerner2025, author = {K{\"o}rner, Tobias}, title = {Effects of Thermopriming on Resilience to Subsequent Stress Conditions in Tomato (Solanum lycopersicum L.)}, volume = {2025}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-1027}, school = {Hochschule Geisenheim University}, pages = {2 -- 116}, year = {2025}, abstract = {Die zunehmende H{\"a}ufigkeit von Hitzewellen und anderen extremen Wetterereignissen bedroht die Ernten weltweit. Herk{\"o}mmliche Anbaumethoden sind nur begrenzt an diese klimatischen Ver{\"a}nderungen angepasst. Daher sind innovative Ans{\"a}tze gefragt, um die Stressresilienz unserer Nutzpflanzen nachhaltig zu erh{\"o}hen. Ein solcher Ansatz ist das Thermopriming, bei dem Pflanzen kontrolliertem Hitzestress ausgesetzt werden. Dieser f{\"u}hrt zur Anreicherung sch{\"u}tzender Pflanzeninhaltsstoffe und verbessert somit die Resilienz der Pflanzen gegen{\"u}ber zuk{\"u}nftigen Stressbedingungen. Diese Dissertation gibt Einblicke in optimierte Thermopriming-Bedingungen f{\"u}r Tomatenjungpflanzen und die langfristigen Auswirkungen von Thermopriming auf Pflanzenwachstum, -entwicklung und -ertrag und schließt damit eine L{\"u}cke in einem bisher wenig untersuchten Forschungsgebiet. Das erste Kapitel konzentriert sich auf die Optimierung des Thermopriming-Regimes, um die Stressresilienz bei Tomatenjungpflanzen zu erh{\"o}hen und gleichzeitig Wachstumshemmungen zu minimieren. Die Experimente zeigten, dass 90-min{\"u}tiges Thermopriming den besten Kompromiss zwischen der Erh{\"o}hung der Flavonolanreicherung in den Bl{\"a}ttern und der Verringerung von Wachstumsverlusten bietet. Diese Ergebnisse zeigen, dass Thermopriming eine praktikable Methode zur Integration in die gartenbauliche Pflanzenproduktion ist, um die langfristige Stressresilienz dieser Modellpflanze zu erh{\"o}hen und die negativen Auswirkungen des Klimawandels zu mildern. Das zweite Kapitel konzentriert sich darauf, wie Thermopriming die Stressresilienz von Tomatenpflanzen erh{\"o}ht und wie die Thermopriming-Behandlung mit anschließendem Salzstress interagiert. Die Ergebnisse zeigten eine signifikante Anreicherung von sch{\"u}tzenden Phenolen und Flavonolen in den Bl{\"a}ttern von thermogeprimten Pflanzen, insbesondere als Reaktion auf den nachfolgenden Salzstress. Diese Ergebnisse zeigen, dass Thermopriming das Potenzial hat, die Produktivit{\"a}t und Qualit{\"a}t von Ernten unter Umweltstress zu sichern und somit von entscheidender Bedeutung f{\"u}r einen nachhaltigen Gartenbau werden kann. Das dritte Kapitel vergleicht die Wirksamkeit von Thermopriming zur Erh{\"o}hung der pflanzlichen Toleranz mit der des chemischen Elicitors Benzothiadiazol (BTH) bei anschließendem Salzstress. Die Studie zeigte, dass BTH zwar die Stresstoleranz bis zu einem gewissen Grad erh{\"o}hte, jedoch das Wachstum und die Fruchtentwicklung negativ beeinflusste. Diese Ergebnisse weisen darauf hin, dass die Dauer der Erholungsphase und der Zeitpunkt des Folgestresses eine entscheidende Rolle f{\"u}r die Wirksamkeit und den Einsatz von Thermopriming spielen. Die Integration von Thermopriming in die Pflanzenproduktion steht im Einklang mit mehreren Nachhaltigkeitszielen der Vereinten Nationen, insbesondere mit Ziel 2 (Kein Hunger), das darauf abzielt, den Hunger zu beenden, die Ern{\"a}hrungssicherheit zu erreichen, die Ern{\"a}hrung zu verbessern und eine nachhaltige Landwirtschaft zu f{\"o}rdern. Es unterst{\"u}tzt auch Ziel 13 (Maßnahmen zum Klimaschutz), das dringende Maßnahmen zur Bek{\"a}mpfung des Klimawandels und seiner negativen Auswirkungen fordert. Dar{\"u}ber hinaus unterst{\"u}tzt Thermopriming die Ziele des European Green Deals, bis 2050 klimaneutral zu werden, die EU-Biodiversit{\"a}tsstrategie f{\"u}r 2030, indem es biodiversit{\"a}tsfreundliche Praktiken f{\"o}rdert, und die EU-Strategie „Vom Hof auf den Tisch", indem es Treibhausgasemissionen reduziert und die Nachhaltigkeit der Pflanzenproduktion und die Vitalit{\"a}t der {\"O}kosysteme f{\"o}rdert. Auf diese Weise kann ein gerechtes, gesundes und umweltfreundliches Lebensmittelsystem unterst{\"u}tzt werden. Zudem kann Thermopriming durch die Verringerung der Abh{\"a}ngigkeit von Pflanzenschutzmitteln und die F{\"o}rderung des {\"o}kologischen Landbaus die negativen Auswirkungen auf die Umwelt und den {\"o}kologischen Fußabdruck verringern. Thermopriming ist eine vielversprechende Strategie, um die Resilienz von Pflanzen gegen{\"u}ber dem Klimawandel zu erh{\"o}hen. Daher sollte die Integration von Thermopriming in die Pflanzenproduktion von politischen Entscheidungstr{\"a}gern und Praktikern in Betracht gezogen werden, um eine nachhaltige Landwirtschaft zu unterst{\"u}tzen, die Abh{\"a}ngigkeit von chemischen Pflanzenschutzmitteln zu reduzieren und die Ernteertr{\"a}ge und -qualit{\"a}t unter verschiedenen (extremen) Umweltbedingungen zu verbessern.}, language = {en} } @phdthesis{Stollberg2024, author = {Stollberg, Maren}, title = {Vertical planting design: The suitability and microclimatic effect of perennials in a textile living wall system.}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-924}, school = {Hochschule Geisenheim University}, pages = {I -- 211}, year = {2024}, abstract = {Urban green infrastructure has gained significant attention in the context of adaptation to climate change because of its positive effects. One approach to enhancing urban green infrastructure is through the use of Living walls (LW), also known as vertical greenery systems. While considerable knowledge and studies on traditional green facades already exist, there is limited information available on LW. Both green facades and LW are associated with numerous well-documented benefits (e.g., biodiversity and clean air), but these benefits depend on the functionality and vitality of the plants. Our knowledge of plants suitable for LW is limited to only a few climate zones and empirical values that lack confirmed validity. To address this gap, we conducted a three-year experiment using a novel, modular LW system on experimental walls exposed with different exposures. The aim of the research was to develop a textile-based, substrate-free Living Wall, which displays a perennial, attractive and diverse plant image and contributes to cooling. In this experiment, we documented the development of the plants, assessed their suitability, and measured the effect of the plants on the ambient temperature. The experiment took place over three years (2017-2019) in Geisenheim, Germany, which has a temperate oceanic climate and falls under the winter hardiness Zone 8a. For the LW system, we utilized a textile-based mat without soil (1 m²) and selected plants from wet/fresh habitats to enhance evaporative cooling. We maintained frequent irrigation with a nutrient solution, resulting in the mat being consistently overwatered. Based on common designs used in landscape architecture and on the conditions of wet habitats, we created three variants: one which was seeded: "Meadow" and two plant modules: "Cascade" and "Ground Cover". Together these modules consisted of 34 perennials and geophytes. Additionally, we sowed seed mixtures of over 30 species on the textile mat (Meadow/Seeding). We also included a Control group without plants, in which moss and weeds developed and were partially removed. After a pre-growing period on horizontal greenhouse tables, we placed the green mats vertically on experimental walls facing north, south, east, and west. Four replicates of each variant were randomly installed. We assessed plant development using various methods, including visual evaluation of aesthetics and growth form, height measurements, photographs, analysis of species coverage and visibility, canopy analysis, winter survival rate, biomass measurement, root position, and leaf area. Additionally, we employed temperature sensors and an infrared (IR) camera to measure the temperature effects of the plants on and of the ambient temperature under different setups. Through the experiment, we gained valuable insights into the techniques, cultivation, and maintenance of LW. Overall, we observed differences in plant development depending on the exposure, season, plant variant, and spontaneous vegetation. The tested plants exhibited a special vertical growth form and height. We noticed delayed growth on the north exposure, with complete coverage achieved in the third year. The south exposure showed particularly high growth, while the east and west exhibited similar but slightly lower growth compared to the south. The perennials retained their visual appearance throughout the year, with almost all variants looking attractive from May to September. Until the onset of winter, all variants had an appealing appearance. Unexpectedly, we observed the establishment of moss. Most plants survived the mild winters (2018/2019), although a cold winter (2017/1018) with a late frost resulted in damage and mortality for many plants. We conducted a detailed analysis of the different plant variants, as follows: The Ground cover variant exhibited an attractive appearance and foliage decoration throughout the year. At the east, west, and north exposures, the plants showed an attractive appearance shortly after winter, while on the south wall, it took until May for the species to start regrowing. In particular, Waldsteinia ternata displayed a nice leaf texture and, together with Pachysandra terminalis, was the most visually appealing. Ajuga tenorii 'Mauro', Alchemilla caucasica, Glechoma hederacea, and Geum coccineum 'Carlskaer' demonstrated beautiful ornamental effects and flowered during the summer. The Cascade variant showcased its attractiveness during the summer season, as most of the plants became less prominent during the winter. We observed that Tellima grandiflora 'Rubra' and Heuchera Hybrid 'Purple Petticoats' were the most visually appealing in this variant. Hosta sieboldii 'Harry van Trier' exhibited a pleasing ornamental effect and flowered during the summer. The ferns exhibited delayed growth but gradually developed a nice leaf texture. Self-settled moss complemented the planting, covering the entire mat. In the Meadow / Seeding variant, we observed increasing growth in height and vegetation coverage that extended from April to October. Initially, we sowed 32 different plant species, but only 10 were able to establish and become visible. These included Galium (album and palustre), Lycopus europaeus s. str., Stachys palustris, Anthoxanthum odoratum s. str., Festuca spp., and Poa spp. It is important to follow maintenance steps for the Meadow-LW. We noticed that the vegetation recovered within a few weeks after cutting. We recommend one complete cut during the summer and the removal of dead plant material after the frost period ends in spring. To examine the temperature effects of the plants on the ambient temperature and the climatic conditions to which they were exposed, we measured the temperature in different setups. The vegetation temperature depends on factors such as air temperature, measurement position, planting variant, and plant species. We observed a cooling effect only at a short distance from the LW, indicating a microclimatic impact. In conclusion, it is possible to effectively green a textile-based, soilless LW system. However, an automated irrigation system and regular monitoring and maintenance are essential. We identified suitable perennial species for each exposure and compiled a list of plants suitable for LW, along with their specific requirements. Seeded meadow-LW can easily be established. Furthermore, we recommend continuing our methodological approaches to obtain temperature measurements in LW in future studies.}, language = {mul} } @phdthesis{Payan2023, author = {Payan, Claire}, title = {Acidification of musts and wines by fumaric acid: Impact of its addition on the chemical and sensory characteristics of varietal wines in the frame of climate change}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-876}, school = {Hochschule Geisenheim University}, pages = {I -- 243}, year = {2023}, abstract = {Climate change is affecting the composition of grape berries and has led to imbalances in the wine matrix, with an increase in alcohol content and a significant decrease in the acidity of wines. In this context, finding solutions to acidify musts and wines is crucial to maintain their stability, preservation, and sensory quality. The main goal of this study was to test the addition of an alternative acid: fumaric acid for must and wine acidification, and to assess its impact on the chemical and sensory characteristics of wines from different grape varieties and origins. A secondary objective was to study the use of fumaric acid to enhance wine preservation, either as a reduction or as an alternative to the addition of sulfur dioxide (SO2) in traditional winemaking and wine preservation. A preliminary study on the chemical properties to define the solubility and acidifying power of fumaric acid, in comparison to tartaric, malic, and lactic acids, was carried out in various hydro-alcoholic matrices, musts, and wines (both white and red). Additionally, a study on its sensory properties was conducted. A simple, quick, reliable, and validated routine analysis method using high-performance liquid chromatography with UV detection (HPLC-UV) was also developed to quantify fumaric acid in various types of wines. This method has a detection limit of 0.2 mg/L and a quantification limit of 0.3 mg/L, with both inter and intra-day repeatability showing an RSD ≤ 2\%. This research work also allowed the evaluation of the impact of adding fumaric acid to Cabernet Sauvignon red wine, compared to the addition of tartaric acid, at different stages of winemaking: during vatting and just after racking. The results of this first study helped understand the role of fumaric acid in winemaking steps, particularly its metabolism when added before alcoholic fermentation. A second study concerns the addition of fumaric acid at different doses (1 g/L and 2 g/L), compared to tartaric acid (1.25 g/L and 2.5 g/L), before bottling Cabernet Sauvignon red wine, revealing its effectiveness in pH control and its potential to reduce the use of SO2. The results of this second experiment revealed a significant impact of adding fumaric acid on phenolic compounds, particularly catechin and epicatechin, which are maintained at higher concentrations over time compared to the control and the modalities with tartaric acid. Finally, the use of fumaric acid in white winemaking, specifically on M{\"u}ller-Thurgau (a German grape variety, Riesling x Sylvaner), was studied. The addition of fumaric acid effectively inhibited malolactic fermentation as effectively as the addition of SO2. The results indicate that adding fumaric acid during preservation and bottling appears as promising alternatives for wine acidification and more sustainable oenological practices that reduce the use of SO2. The concrete results obtained justify the inclusion of must and wine acidification with fumaric acid by the OIV in the International Code of Oenological Practices of the OIV. Further studies should refine the use and functionalities of fumaric acid on musts (in particular) and wines.}, language = {en} } @phdthesis{Ponchon2024, author = {Ponchon, Mathilde}, title = {The entomopathogenic fungus Metarhizium robertsii and its endophytic potential in grapevine to regulate radicicole grape phylloxera populations}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim University}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-865}, school = {Hochschule Geisenheim University}, pages = {3 -- 212}, year = {2024}, abstract = {Grape phylloxera Daktulosphaira vitifoliae destroyed 30\% of the European vineyard by the end of the 19th century, attacking the woody roots of the grapevine Vitis vinifera (L.). To date, grafting grapevine on American resistant rootstocks is the leading solution to control the pest. However, grape phylloxera is present in most wine-growing soils and remains a threat in regions planted with non-grafted vines. Thus, alternative control solutions are investigated. The entomopathogenic fungus Metarhizium robertsii is known for its capacity to parasitize insects. Besides, the fungus can colonize plant rhizosphere and establish as an endophyte (i.e., within plant tissues) in many plant species. The thesis aimed to investigate if M. robertsii could persistently associate with the rhizosphere and as an endophyte in non-grafted grapevine V. vinifera without harming its growth while preventing the development of the grape phylloxera radicicole forms. Four M. robertsii strains native to four different vineyards were used and came from: i) the center-West Argentina (MsoilAR4.3), ii) the south of Australia (M224B), iii) the south-west of France (EF3.5(2)) and iv) the west of Germany (EF047). Greenhouse experiments were conducted to assess the association between M. robertsii and potted non-grafted grapevines. First, the comparison of the kinetic of grapevine rhizosphere and endosphere colonization was made, comparing the strain EF3.5(2) with a laboratory strain non-native to the vineyard (ARSEF-2575-GFP) to evaluate if a vineyard-native strain had a more durable colonization. Droplet Digital PCR (ddPCR), a culture-based method, and confocal imaging of root segments were used to characterize the associations. The strain EF3.5(2) had a higher establishment in the rhizosphere and root-endosphere of non-grafted grapevine than the strain ARSEF-2575-GFP. Both strains were established for up to 96-98 days post-inoculation (dpi) in both compartments. Then, the potential of association with the non-grafted grapevine of all four-vineyard native M. robertsii strains was compared. The rates of rhizospheric colonization at 68-70 dpi ranged from 60\% for the Argentinian MsoilAR4.3 strain, 65\% for the Australian M224B strain, 76\% for the French EF3.5(2) strain, to 100\% for the German EF047 strain. The rates of root endosphere colonization were 14\%, 10\%, 5\%, and 33\% at 68-70 dpi, respectively. No significant differences of rhizosphere and root-endosphere colonization between tested strains were recorded. Also, the fungal association unaffected the grapevine's growth and leaf pigment content during the experimental period. Finally, the effect of direct parasitism of the strain EF3.5(2) on the survival and development of radicicole grape phylloxera clone 'Pcr7' was evaluated in the woody root section bioassay. Depending on the method used to infect the insect, a significant reduction of 90 \%, 70 \%, and 86\% in survival probability was found, and 92\%, 89\%, and 93 \% in reduction of adults' development compared with control treatments. Also, the symptoms induced by grape phylloxera on non-grafted grapevines co-inoculated with M. robertsii were reduced by 91\% (mean of 4.8 ± 8.4 nodosities) compared with the phylloxera infested-plants (mean of 52.7 ± 50.7 nodosities). The qPCR analysis performed on grapevine inoculated with strain EF3.5(2) showed after 24h, the up- regulation of the VvWRKY-75, VvPR3.2, VvPR4, and VvG1, which are phylloxera-responsive defense genes involved in the resistance against phylloxera. In conclusion, M. robertsii's persistent association with non-grafted grapevine represents an alternative protection strategy against radicicole grape phylloxera, especially for wine-growing regions planted with non-grafted vines. Further field experiments should be carried out to determine the environmental factors affecting the effectiveness and persistence of M. robertsii associated with grapevine.}, language = {en} } @phdthesis{Moulis2024, author = {Moulis, Pierre}, title = {Exploration of the phenomena associated with the production of pyrrole and pyridine derivatives responsible for mousy off-flavours in wine}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-880}, school = {Hochschule Geisenheim University}, pages = {I -- 152}, year = {2024}, abstract = {In den letzten Jahren ist die Nachfrage der Verbraucher nach Bio-Lebensmitteln weiter gestiegen. Die Akteure des Weinsektors achten auf diese Erwartungen. In der Weinproduktion ist ein R{\"u}ckgang in der Anwendung bestimmter Maßnahmen, die sich direkt auf die Weinqualit{\"a}t auswirken k{\"o}nnen, zu verzeichnen. So hat beispielsweise der „M{\"a}uselton" bei Weinen mit reduziertem Sulfitgehalt zugenommen. Derzeit scheinen drei Molek{\"u}le Verursacher dieses Defekts zu sein: 2-Acetylpyrrolin (APY), 2-Acetyltetrahydropyridin (ATHP) und 2-Ethyltetrahydropyridin (ETHP). Die durchgef{\"u}hrte Forschungsarbeit, die chemische, mikrobiologische und {\"o}nologische Ans{\"a}tze kombiniert, liefert Antworten auf die Mechanismen des Auftretens dieses Fehltons im Wein. Um Antworten zu finden, wurden Methoden zur Quantifizierung der N-Heterozyklen, die f{\"u}r den „M{\"a}uselton" verantwortlich sind, mithilfe von SBSE-GC-MS-Techniken entwickelt. Die Bestimmungsmethode f{\"u}r Wein erm{\"o}glichte es, diese Substanzen in 74 verschiedenen Weinen zu quantifizieren. Die zweite Analysenmethode ist auf ein chemisch definiertes Medium abgestimmt, das alle bisher bekannten Vorstufen des „M{\"a}useltons" enth{\"a}lt. Sie erm{\"o}glicht es, Mikroorganismen unter standardisierten Bedingungen auf ihre F{\"a}higkeit zu testen, einen „M{\"a}uselton" zu erzeugen. Mit diesen Methoden konnte gezeigt werden, dass das Verh{\"a}ltnis der beiden Tautomere von 2-Acetyltetrahydropyridin nicht von den Unterschieden zwischen dem pH-Wert des Weines und der Mundh{\"o}hle beeinflusst wird. Mikroorganismen wurden aus 25 Weinen mit „M{\"a}uselton" isoliert. Die am h{\"a}ufigsten anzutreffenden Arten sind Saccharomyces cerevisiae, Oenococcus oeni oder Brettanomyces bruxellensis. Von den 353 isolierten Mikroorganismen sind nur St{\"a}mme der Arten B. bruxellensis, Lentilactobacillus hilgardii und Oenococcus oeni in der Lage, Substanzen, die einen „M{\"a}uselton" verursachen, im Modellmedium zu produzieren. Anschließend wurden St{\"a}mme aus der Sammlung, die zu diesen drei Arten geh{\"o}rten, unter denselben Bedingungen untersucht. Die Ergebnisse zeigen, dass die Konzentrationen und Verh{\"a}ltnisse der drei N-Heterozyklen signifikante Unterschiede zwischen den Arten aufweisen, dass jedoch alle untersuchten St{\"a}mme (22 St{\"a}mme von B. bruxellensis, 10 St{\"a}mme von L. hilgardii, 20 St{\"a}mme von O. oeni) die F{\"a}higkeit haben, mindestens eine der drei Komponenten zu produzieren. Weitere Versuche in Modellmedien haben gezeigt, dass es bei der Produktion m{\"a}uselnder Substanzen zu einer Interaktion zwischen Mikroorganismen kommen kann. Die Untersuchung dieser Wechselwirkungen wurde im Weinmilieu fortgesetzt. Ein Ugni blanc Most wurde mit zwei verschiedenen Saccharomyces cerevisiae St{\"a}mmen vinifiziert. Anschließend wurde die Produktion der m{\"a}uselnden Komponenten {\"u}ber 24 Tage verfolgt. Die Ergebnisse zeigten, dass unabh{\"a}ngig von den produzierenden Mikroorganismen einer der beiden S. cerevisiae St{\"a}mme zur Entwicklung von Bedingungen beitr{\"a}gt, die eine h{\"o}here APY-Produktion im Wein erm{\"o}glichen. Schließlich wurden Produktionskinetiken im Modellmedium durchgef{\"u}hrt, um festzustellen, in welchem physiologischen Stadium B. bruxellensis diese Verbindungen produzieren kann. Die Produktion von ATHP verl{\"a}uft nicht linear. Die Verbindung tritt punktuell in hohen Konzentrationen auf, insbesondere zu Beginn der station{\"a}ren Wachstumsphase, und verschwindet dann wieder. Es wurden Hypothesen {\"u}ber die physiologische Rolle dieser Verbindung aufgestellt. Schl{\"u}sselw{\"o}rter: M{\"a}uselton; Weine; Brettanomyces bruxellensis; Milchs{\"a}urebakterien; Organoleptische Abweichungen}, language = {en} } @phdthesis{Dries2024, author = {Dries, Leonie}, title = {Microbial structure and diversity in the rhizosphere of grape vines (Vitis vinifera L.)}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-827}, school = {Hochschule Geisenheim University}, pages = {II -- 133}, year = {2024}, abstract = {Microorganisms are a substantial component of the rhizosphere, and the activity and composition of rhizosphere microbial populations markedly affect interactions between plants and the soil. In addition, the microbiota of the rhizosphere can positively influence plant development, growth and vitality. In vineyards, management practices influence both grapevine root growth directly and the rhizosphere microbiota, but the exact mode of action is largely unknown. Recently, however, two new research approaches are increasingly coming into focus to enhance the grapevine growth and health: plant engineering and rhizosphere engineering (Chapter 1). In plant engineering, knowledge about plant-microbiome interactions is used for plant breeding strategies. In rhizosphere engineering, microbial communities are modified by adding specific fertilizers, nutrients, or by bio-inoculation with certain bacteria and/or fungi. Taken together, these new methods suggest a potential for reaching a more sustainable development of a pesticide- and fertilizer-reduced viticulture in the future. Consequently, the aim of this study was to investigate the bacterial rhizobiome of grapevines (Vitis vinifera L.) under different experimental designs. By characterizing the bacterial 16S rRNA gene, a statement on the existing bacterial communities and their diversity can be made and compared under different environmental conditions. For this, a method has to be established that allows to obtain rhizosphere and root material of grapevine plants, and to prepare it for sequencing and further analyses. This applies both to grapevines cultivated in greenhouses under controlled conditions as well as to variants under field conditions. The experimental designs aimed to gain knowledge regarding the bacterial diversity of the grapevine rhizosphere including different grape varieties, different grapevine rootstocks as well as different fertilization measures. The first experiment aimed to investigate the variability of the rhizosphere microbiome resulting from the genotype of the rootstock while minimizing the effect of all other environmental factors. This was made possible by investigating four ungrafted grapevine rootstock varieties of the same age, grown on the same soil under the same climatic conditions and managed identically. The bacterial communities associated with the rhizosphere of the rootstocks 1103 Paulsen, 140 Ruggeri, 161-49 Couderc, and Kober 5BB were characterized with the amplicon based sequencing technique, targeting regions V4-V5 of 16S rDNA gene. The four rootstocks showed similarities concerning the structure of the bacteria assemblage (richness and evenness). Nonetheless, differences were detected in the composition of the bacterial communities. Indeed, all investigated rootstocks recruited communities with distinguishable traits, thus confirming the role of rootstock genotype as driver of the bacteria composition (Chapter 2). In order to disentangle the effect of scion and rootstock, the rRNA (V4-V5 region of 16S rRNA) extracted from the rhizosphere of the grape varieties Riesling and Mueller-Thurgau ungrafted vs. grafted on different rootstocks were sequenced in three experimental set-ups in two different years. The bioinformatic analysis with tools designed to be robust for compositional data showed, that the investigated rootstocks or scions or combinations, respectively, recruited bacterial communities with distinguishable traits. Statistical differences were revealed between ungrafted Riesling and Mueller-Thurgau, and between grafted Riesling and ungrafted Riesling, and ungrafted Mueller-Thurgau and grafted Mueller-Thurgau. Thus, confirming the role of scion and rootstock genotype as a driver of the structure and composition of bacterial communities in the rhizosphere of grapevines (Chapter 3). In order to investigate the impact of different levels of nitrogen (N) fertilization on the rhizosphere microbiome an experimental vineyard with vines (Vitis vinifera L. cv. Pinot Noir) in large containers was examined in 2020 and 2021 at bud break. The vines were fertilized with two different levels of nitrogen added per year (N0 25 kg/ha and N1 75 kg/ha) individually. In order to examine the respective bacterial communities, rhizosphere material was sampled and a subsequent RNA-extraction followed by next generation sequencing was performed. The study revealed significant differences in the bacterial communities in the rhizosphere regarding fertilization levels and sampling depths. The results may help to understand the effect of nitrogen fertilization on the microbiome and, in the long term, reduce fertilization in viticulture, leading to more sustainable vine management (Chapter 4). Hence, superordinate, the future aim is to use new insights to enable more precise plant nutrition in the form of more accurate fertilization recommendations in order to reduce the associated costs in an economical and environmentally friendly way. A more precise knowledge of the specificity and dynamics of the grapevine rhizosphere microbiome under different management practices, grape varieties, rootstocks, and fertilization levels, should enable targeted adaptation strategies for increasingly frequent extreme years leading to a more sustainable viticulture.}, language = {en} } @phdthesis{Badura2024, author = {Badura, Jennifer}, title = {Characterization, regulation and genetic modification of the synthesis of aroma compounds in non-conventional wine yeasts}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim University}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-809}, school = {Hochschule Geisenheim University}, pages = {II -- 223}, year = {2024}, abstract = {Yeasts belonging to the genus of Hanseniaspora are widespread in nature and are generally part of the microbiome of ripe fruits, such as apples, pears and grapes. Hanseniaspora spp. form 50-75\% of the microorganisms found at the onset of grape must fermentations, H. uvarum often being the most abundant. H. uvarum is also a common isolate from other fruits, such as oranges, pineapples, mangoes, apples and pears. Since H. uvarum, known for producing high amounts of acetic acid and ethyl acetate, dominates the onset of spontaneous grape must fermentations, it greatly influences the aroma profile of wines. Besides its important role in fermentations, more biotechnological research has been reported in recent years, highlighting the universal value of H. uvarum beyond the beverage industry. In this thesis, I characterized the aroma-production profile of seven different Hanseniaspora spp. in simultaneous co-fermentations with Saccharomyces cerevisiae. Significant differences could be detected between fermentations using Hanseniaspora spp. belonging to the fast-evolving lineage (FEL) and the slow-evolving lineage (SEL). Fermentations with yeasts of FEL showed increased amounts of ethyl acetate, whereas yeasts belonging to SEL revealed no meaningful difference compared to the pure S. cerevisiae fermentation. Furthermore, co-fermentations resulted in lactic acid depletion (H. osmophila), extremely high isoamyl acetate levels (H. guilliermondii), reduction in glycerol (H. occidentalis), increased terpenols (H. opuntiae) as well as esterified terpenes (H. guilliermondii and H. uvarum). This is the first study to investigate the use of H. nectarophila and H. meyerii in relation to wine, of which fermentations using H. nectarophila revealed high levels of acetate esters. Nitrogen sources in form of amino acids have a major impact on the resulting aroma-production profile of yeasts as they serve as backbones for several volatile organic compounds. I explored amino acid uptake preferences of Hanseniaspora spp. of both lineages (H. uvarum = FEL; H. osmophila = SEL), S. cerevisiae (all glucophilic), as well as the fructophilic yeasts Starmerella bacillaris and Zygosaccharomyces rouxii in synthetic must, spiked with single amino acids. Among yeasts investigated, H. uvarum showed the most rapid amino acid uptake. Additional research on yeast fermentations with synthetic must supplemented with an amino acid mix resulted in amino acid-dependent synthesis of specific aroma compounds by the respective yeast. This study reveals similarities in both preferences in amino acid uptake and nitrogen source depending aroma compound synthesis of H. osmophila and S. cerevisiae. I investigated the transcriptomic profile of H. uvarum and S. cerevisiae to gain insight into the different regulation mechanisms involved in the synthesis of aroma compounds. Furthermore, I explored the impact of different levels of nitrogen (nitrogen deficiency/ diammonium hydrogen phosphate (DAHP) supplemented must) within the grape must on the gene expression profile and therefore on the resulting aroma profile. Even though the different nitrogen regimes did not significantly affect transcriptional levels, a major impact on both fermentation kinetics and the aroma profile could be monitored. H. uvarum unravelled possessing additional genes including alcohol acetyltransferase activity leading to a rapid esterification of higher alcohols to acetate esters. In addition, the lack of genes involved in the synthesis of higher alcohols and ethyl esters, as well as an up-regulation of genes responsible for the synthesis of acetyl-coA and acetate esters favour the high acetate ester production. In this study, I developed the first genetic modification tool for H. uvarum by constructing a synthetic marker gene encoding the hygromycin marker under the control of a H. uvarum promoter, flanked by ~1 000 bp homology region to the target locus, enabling the knock-out of one copy of the alcohol acetyltransferase 1 (ATF1) gene. By increasing the concentration of the antibiotic during selection, I could identify a knock-out of both ATF1 alleles in the diploid yeast, generating a homozygotic atf1 mutant. Fermentations resulted in a significant reduction of the acetate ester synthesis, proving the function of ATF1 as an important gene involved in the ester synthesis in H. uvarum. Genetic modification of H. uvarum was optimized by establishing a rapid PCR-based gene targeting approach for one-step gene replacement. Generation of two novel synthetic antibiotic resistance genes (pFA-hygXL and pFA-clnXL) provided resistance against hygromycin and nourseothricin, respectively. Short flanking-homology regions of 56-80 bp added to these selection markers via PCR enabled gene targeting and the deletion of both the H. uvarum LEU2 and LYS2 genes via two rounds of consecutive transformations, generating a leucine auxotrophic leu2/leu2 mutant and a lysine auxotrophic lys2/lys2 mutant, respectively. The genetic modification approach of H. uvarum using PCR-based gene targeting was further validated by targeted complementation of the auxotrophic leu2/leu2 strain.}, language = {en} } @phdthesis{Wersebeckmann2024, author = {Wersebeckmann, Vera}, title = {Terracing in steep slope viticulture and its potential to promote biodiversity in vineyard ecosystems}, volume = {2024}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-760}, school = {Hochschule Geisenheim University}, pages = {212}, year = {2024}, abstract = {A substantial area of the terrestrial surface is used for agricultural production. In Europe, many farmland species and ecosystems have evolved with traditional agricultural practices and rely on extensive cultivation for their survival. Today, agrobiodiversity is threatened by the abandonment of traditional agricultural land use. The cultivation of wine is one of the oldest forms of agriculture. On steep slopes, viticulture has shaped landscapes, cultural traditions, and unique ecosystems in many regions. In Germany, steep slope viticulture has been declining dramatically in recent decades due to insufficient profitability. The abandonment of these traditional cultural landscapes threatens the cultural heritage and the flora and fauna adapted to viticultural management. One solution to halt the decline of steep slope viticulture could be a change of cultivation system from vertically oriented rows to modern terraced vineyards. Here, the rows run parallel to the hillside, facilitating cultivation, and thus reducing production costs. At the same time, a large portion of terraced vineyard consists of uncultivated embankments, which can provide valuable habitats within the agricultural system. However, little is known about the effects of a cultivation system change and vineyard abandonment on biodiversity. In addition, information on how to sustainably revegetate terrace embankments is missing. Within the framework of this dissertation, the overall aim was to evaluate the potential of terraced vineyards to promote biodiversity and investigate measures for sustainable revegetation of terrace embankments. In addition, the effects of distinct vineyard management (vertically oriented vs. terraced) and vineyard abandonment on biodiversity were assessed. The main part of this thesis is based on a field study comparing three vineyard types (vertically oriented vineyard, terraced vineyard, abandoned vineyard) that were arranged in 15 triplets along the Upper Middle Rhine Valley (UMRV) in Germany. The effects of vineyard types, local vineyard parameters, and landscape structure on biodiversity were evaluated using four species groups. Studied groups represented plants and arthropod species (grasshoppers, wild bees, spiders). In a second field study, three newly constructed terrace embankments were revegetated using different seeding techniques and seed mixtures. In addition, measures to support plant establishment were evaluated. Plant establishment was assessed for three consecutive years in permanent vegetation plots. The first study on the three vineyard types revealed that there was no uniform positive effect of one vineyard type on all investigated groups. Instead, the responses were group and taxon-specific and driven by management-related disturbance intensities, local vegetation structures, soil and landscape structure. In total, the heterogeneous landscape and small-structured vineyard agroecosystem of the UMRV supported high species diversity, hosted high numbers of rare and threatened species, and diverse species communities across vineyard types. Plant species richness was enhanced by vineyard management and particularly benefited from terraced vineyards and rather nutrient-poor and extensively managed embankments. In comparison, plant communities of fallows were completely different with lower plant diversity. Grasshoppers were supported by vineyard management, and bare ground in vineyard inter-rows supported heat- and open-adapted species. Taller vegetation stands on terrace embankments enhanced grasshopper species richness while woody structures and vineyard abandonment reduced grasshopper diversity and abundance at the local and landscape scale. Wild bee species richness and abundance were strongly determined by their nesting needs. For ground-nesting bees, the suitability of soils for nesting was important, irrespective of vineyard management types whereas above-ground nesting bees were enhanced by woody structures of fallows at the local and landscape scale. Moreover, fallows further provided valuable floral and non-floral resources for both ground- and above-ground nesting bees. For spiders, there was no difference in species richness and abundance between vineyard types but many xerophilic species adapted to open habitat structures prevailed in terraced vineyards. Vineyard fallows supported highly distinct spider communities, including some late-successional species. In conclusion, the vineyard cultural landscape of the UMRV with both actively managed and abandoned vineyards led to a high diversity of plant and arthropod communities. Hence, for its preservation, a spatially heterogeneous landscape comprising both (semi) natural and viticultural-management elements is important. Results from the second study showed that terraced vineyards and especially terrace embankments can contribute to promoting biodiversity, especially if they are revegetated with regional seed mixtures. Seeds of locally adapted populations and hydro-seeding provided higher vegetation cover which is needed to prevent severe erosion whilst non-locally adapted standard seed mixtures and manual seeding had a higher failure risk and were more prone to severe precipitation events. Taken together, vineyard terracing appears to be a win-win solution for both winegrowers and biodiversity and thus helps to maintain viticulture on steep slopes.}, language = {en} } @phdthesis{Muschkullus2023, author = {Muschkullus, Thomas}, title = {Umgang mit der Komplexit{\"a}t naturschutzrelevanter Großprojekte}, volume = {2023}, edition = {1. Auflage}, publisher = {Gesellschaft zur F{\"o}rderung der Hochschule Geisenheim}, address = {Geisenheim}, isbn = {13978-3-934742-90-1}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-664}, school = {Hochschule Geisenheim University}, pages = {507}, year = {2023}, abstract = {Großprojekte der Verkehrsinfrastruktur sind komplex und beeinflussen Schutzg{\"u}ter in hohem Maße; sie besitzen somit in aller Regel eine starke Relevanz f{\"u}r Ziele des Naturschutzes. Die Komplexit{\"a}t hat zur Folge, dass planerische Entscheidungen unter hohen Risiken und nicht dergestalt abgewogen werden, wie dies u.a. gem{\"a}ß dem Gesetz {\"u}ber die Umweltvertr{\"a}glichkeitspr{\"u}fung (UVPG) erforderlich ist. Die vorliegende Dissertation geht der Frage nach, wie mit dieser Komplexit{\"a}t umgegangen werden kann, um den Erfolg der Vorhaben zu optimieren.}, language = {de} } @phdthesis{Strack2022, author = {Strack, Timo}, title = {Comparison of terraced and steep slope vineyards emphasizing the impact of an altered viticultural system regarding physiology, health status and distinctive berry quality parameters of the grapevine}, volume = {2023}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-731}, school = {Hochschule Geisenheim University}, pages = {I -- 93}, year = {2022}, abstract = {In der Vergangenheit trugen Weine aus Steilstlagen zu einem maßgeblichen Teil zur Reputation deutscher Spitzenweine im nationalen und internationalen Vertrieb bei. Die historischen Weinlagen pr{\"a}gten die Kulturlandschaft und deren Entwicklung. Der deutsche Steillagenweinbau steht jedoch vor großen Herausforderungen. Bereits in den letzten Jahrzehnten wurde die Bewirtschaftung eines großen Teils steiler Weinbergsfl{\"a}chen aufgegeben. Die Gr{\"u}nde hierf{\"u}r sind vielf{\"a}ltig. Die im Vergleich zu direktzugf{\"a}higen Weinbergen in der Ebene kostenaufwendigere Kultivierung von Steillagen geht mit einer h{\"o}heren k{\"o}rperlichen Belastung und einem zus{\"a}tzlich h{\"o}heren Unfallrisiko einher. F{\"u}r viele Nachwuchskr{\"a}fte ist die Arbeit im Steillagenweinberg daher wenig attraktiv; f{\"u}r viele praktizierende Betriebe zu teuer. Doch auch der allgegenw{\"a}rtige Klimawandel wirkt auf die flachgr{\"u}ndigen Steillagen mit geringen Bodenauflagen unter zuk{\"u}nftig l{\"a}nger andauernden Trockenperioden, einer h{\"o}heren Verdunstung und generell unregelm{\"a}ßigeren, jedoch h{\"a}ufiger werdenden Starkniederschlagsereignissen, negativ auf die Ertragsstabilit{\"a}t und die allgemeine Traubenqualit{\"a}t ein. Dies betrifft vor allem die stark sonnenexponierten, flachgr{\"u}ndigen S{\"u}dh{\"a}nge steiler Weinbergslagen. Die moderne Querterrassierung von Weinbergen stellt eine m{\"o}gliche Alternative zur gegenw{\"a}rtigen Bewirtschaftung von Reben in der Falllinie dar. Die hangparallele Zeilenf{\"u}hrung auf Terrassenplattformen l{\"a}sst nicht nur einen h{\"o}heren Grad der Weinbergsmechanisierung zu. Die ebenen Terrassenfl{\"a}chen k{\"o}nnen den Oberfl{\"a}chenabfluss verringern und erlauben eine h{\"o}here Infiltration von Niederschl{\"a}gen, so dass eine Abschwemmung des fruchtbaren Weinbergsbodens reduziert oder verhindert und das Wasser im Boden besser zur{\"u}ckgehalten werden kann. In der vorliegenden Arbeit wurde untersucht welche Auswirkungen die Umstrukturierung von Falllinienweinbergen zu hangparallel verlaufenden Querterrassen auf mikroklimatische Parameter, die Bodenwasserdynamik und letztlich auf die vegetative und generative Leistung der Rebe hat. Die bis zu sieben untersuchten Weinbergspaare, bestehend aus Falllinienweinberg und Querterrasse, wurden entlang des unteren Rheingaus und des oberen Mittelrheintals hinsichtlich ihrer r{\"a}umlichen N{\"a}he zueinander und der Vergleichbarkeit des Pflanzguts untereinander ausgew{\"a}hlt und {\"u}ber einen Zeitraum von zwei bis vier Jahren begleitet. Es konnte gezeigt werden, dass eine durch die Weinbergstransformation orthogonal zur urspr{\"u}nglich in Falllinie verlaufenden Zeilenorientierung in einer Ver{\"a}nderung der Strahlungsverteilung und des W{\"a}rmehaushalts resultiert. Querterrassen konnten Wetterextreme abschw{\"a}chen und bewiesen eine f{\"u}r den Reifeabschluss beg{\"u}nstigte Besonnung der Traubenzone. Dies zeigte sich deutlich in der Unterscheidbarkeit der Gehalte qualit{\"a}tsbestimmender Traubeninhaltsstoffe, wie zum Beispiel Polyphenole und Aminos{\"a}uren. J{\"u}ngere Reben, die am {\"a}ußeren Ende der Terrassenplattform gepflanzt wurden, wiesen {\"u}ber alle Versuchsjahre hinweg hohe Trockenstressreaktionen auf. Dies milderte sich jedoch mit fortschreitendem Rebalter ab. Die Querterrassierung von Steillagenweinbergen erwies sich als probates Mittel zur Erzeugung hochwertigen Traubenmaterials. Zudem erg{\"a}nzt das Potential zur F{\"o}rderung der Artenvielfalt durch eine nachhaltige Bewirtschaftung der Terrassenb{\"o}schungen die als insgesamt positiv zu wertenden Versuchsergebnisse der vorliegenden Arbeit. Einzig die Herausforderung der z{\"u}gigen Etablierung bzw. Konkurrenzf{\"a}higkeit von Jungreben im Steillagenweinberg stellt nach wie vor eine Schwierigkeit dar, die es mit weinbaulichen, technischen oder z{\"u}chterischen Maßnahmen zu l{\"o}sen gilt.}, language = {en} } @phdthesis{Cotea2022, author = {Cotea, Victor}, title = {The removal of volatile phenols from Brettanomyces-contaminated wine using Molecularly Imprinted Polymers}, volume = {2022}, edition = {1. Auflage}, publisher = {Gesellschaft zur F{\"o}rderung der Hochschule Geisenheim}, address = {Geisenheim, Deutschland}, isbn = {13 978-3-934742-89-5}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-747}, school = {Hochschule Geisenheim University}, pages = {I -- 239}, year = {2022}, abstract = {Brettanomyces infections represent one of the major red wine quality spoilers affecting the industry worldwide and will most likely continue to be so in the years to come. When attempting to correct or "cure" a Brettanomyces tainted wine, the most problematic metabolites to be removed are volatile phenols, particularly 4-ethylphenol. Molecular imprinting represents one of the technologies which promise to bridge the gap between the precision and selectivity of chemical analytical methods for investigating liquid matrices, and that of industrial filtration and separation technologies currently in use. In this work, the removal of 4-ethylphenol from wine with the aid of molecularly imprinted polymers was studied. Overall, the materials investigated in this work show promise when investigated in lab-scale conditions with model solutions. They can be effective in treating wine if the treatment conditions are appropriate and involve multiple regeneration steps.}, language = {en} } @phdthesis{Blois2023, author = {Blois, Louis}, title = {Genetic architecture of root related traits and scion respones induced by grapevine rootstock. First study in a monospecies population of Vitis berlandieri}, volume = {2023}, edition = {1. Auflage}, publisher = {Hochschule Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-676}, school = {Hochschule Geisenheim University}, pages = {3 -- 249}, year = {2023}, abstract = {In the context of climate change, crop adaptation is of major interest. Adaptation can be achieved by modifying cultural practices, field management, or plant material. In grafted plants, the plant material can be improved by the scion or the rootstock. The rootstock comprises the anchorage and the nutrient and water absorption as well as hormone signaling, which are closely involved in plant adaptation to its environment. Moreover, the interactions between the scion and the rootstock provides a broad range regarding adaptation strategies to different growing conditions and production aims. In vineyards, the most commonly rootstocks are hybrid breeds between American Vitis species (V. berlandieri, V. riparia, and V. rupestris) and sometimes V. vinifera. Despite recent findings revealing a large genetic diversity in these genetic backgrounds, rootstocks remain poorly studied, especially at the genetic level. The V. berlandieri hybrids have shown good performances in water deficit and limestone tolerance in vineyards. A selection of 286 V. berlandieri genotypes were chosen from a field-grown population of plants obtained from seedlings at Hochschule Geisenheim University, Germany. The samples were analysed regarding their genetic structure, which revealed two subpopulations and an association between the climatic conditions of the sampling areas and their genetic variability. While an isolation by distance has been highlighted, it was not possible to detect the variability in the genetic burden of the two subpopulations. This population was used for grafting of V. vinifera cv. Riesling (clone 24-209Gm), which was planted in pots and grown in the greenhouse fortwo consecutive years with no limiting conditions. A root phenotyping has been carried out after one year of growing, revealing a high variability at the phenotype and genetic level. The heritability was high for these traits which allowed to carry out a genome wide association study and to detect eleven genetic markers associated with root-related traits. Each year, the population was planted in a field experiment in order to observe the variability of conferred traits induced by the rootstock to the scion. A medium to high variability has been detected for the pruning weight and the δ13C as well as a medium to high heritability. A genome wide association study has allowed us to detect two significant markers for δ13C but no markers were highlighted for the pruning weight. Correlations between root-related and scion conferred traits have been found. A comparison of the phenotypical performance of the V. berlandieri genotypes to commercial rootstocks, i.e. SO4, 110R, B{\"o}rner and 5BB, resulted in interesting insights for the selection of futuregenotypes for rootstock breeding. This association study is the first carried out in a natural population of a wild Vitis monospecies and highlights new opportunities for grapevine rootstocks breeding.}, language = {en} } @phdthesis{Kahn2023, author = {Kahn, C{\´e}cile}, title = {Study of the impact of atmospheric CO2 level on grapevine leaf physiology, berry maturation and composition at harvest, using a FACE (Free Air Carbon dioxide Enrichment) system}, volume = {2023}, edition = {1. Auflage}, publisher = {Gesellschaft zur F{\"o}rderung der Hochschule Geisenheim}, address = {Geisenheim}, url = {http://nbn-resolving.de/urn:nbn:de:hebis:2083-724}, school = {Hochschule Geisenheim University}, pages = {205}, year = {2023}, abstract = {Climate change cannot currently be ignored and impacts all fields of agriculture. IPCC reports forecast an increase of up to 700 ppm of atmospheric carbon dioxide concentration at the end of the 21st century. Parameters such as elevated global temperature, reduced precipitations in certain areas of the world and increase of atmospheric carbon dioxide concentration are modifying plants' environment. Grapevine, which is a crop of economic and cultural importance, is very sensitive to climate modifications. The effects of temperature or water stress on grapevine has been widely investigated, and elevated carbon dioxide has been mainly studied in enclosed systems such as greenhouses. However, the impact of increased concentration of carbon dioxide on plants in open-field experiments remains scarcely studied because of the technical challenge that it represents. In this context, the aim of this PhD work was to investigate the impact of elevated carbon dioxide concentration using the set-up VineyardFACE located at Geisenheim University. This open field set-up enables to apply a moderate and gradual increase (+20\%) of ambient carbon dioxide concentration on two grapevine cultivars, Riesling, and Cabernet Sauvignon. While knowing the impact of elevated carbon dioxide treatment on leaf physiology and vegetative growth from previous studies (Wohlfahrt et al., 2018), as well as on berry composition during the early years of fumigation, the goal of this study was to determine the effects of elevated carbon dioxide treatment on agronomical traits, primary metabolites (sugars, organic acids, amino acids) and secondary metabolites (anthocyanins, terpenes) on vines undergoing six years of fumigation, as well as monitoring berry development and following berry ripening for successive seasons. Intermediates from central metabolism were also studied for two years (2020 and 2021), and terpene analysis was realized on Riesling must 2021. Our results showed that although photosynthesis was still enhanced, little effects were found of elevated carbon dioxide treatment on primary metabolites as well as on berry ripening rates, for successive seasons for both Riesling and Cabernet Sauvignon. However, a trend of reduced total anthocyanins concentration in Cabernet Sauvignon was demonstrated by elevated carbon dioxide treatment mainly in 2020, while anthocyanins composition remained fairly similar. Terpenes (both bound and free) composition in Riesling in 2021 was not impacted by elevated carbon dioxide treatment.}, language = {en} }