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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.
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.
Großprojekte der Verkehrsinfrastruktur sind komplex und beeinflussen Schutzgüter in hohem Maße; sie besitzen somit in aller Regel eine starke Relevanz für Ziele des Naturschutzes. Die Komplexität hat zur Folge, dass planerische Entscheidungen unter hohen Risiken und nicht dergestalt abgewogen werden, wie dies u.a. gemäß dem Gesetz über die Umweltverträglichkeitsprüfung (UVPG) erforderlich ist. Die vorliegende Dissertation geht der Frage nach, wie mit dieser Komplexität umgegangen werden kann, um den Erfolg der Vorhaben zu optimieren.
Historically and under cooler climate conditions, steep slope vineyards yielded best quality wines and highest reputation, due to their distinctive light microclimate, especially pronounced at the end of the ripening period. Today, German steep slope viticulture is facing major challenges. The cultivation of steep vineyard sites is costly. Compared to fully-mechanized vineyards, steep slope vineyards are labour-intensive and strenuous to manage, they produce less yield and are at higher risk of the adverse effects of a changing climate.
The modern vineyard terracing may be a viable alternative to the current cultivation method of downslope planted grapevines. The terrace platforms lead along the contour line of the hill and allow a higher degree of vineyard mechanization. The flat terrace platforms reduce surface runoff and allow for greater infiltration of precipitation, thus reducing or preventing runoff of the fertile vineyard soil and enhance the retention of precipitation in the soil.
In the present work, the effects of the transformation of vineyards planted downslope to modern vineyard terraces on microclimatic parameters, soil water dynamics and, finally, on the vegetative and generative performance of the grapevine were investigated. The experimental sites, comprising a vineyard planted downslope and a modern terrace, were selected with regard to their spatial proximity to one another and the comparability of the planting material with each other and monitored over a period of two to four years.
The change in the radiation distribution and the heat balance became apparent due to the inherent row orientation change by vineyard terracing, leading to an alteration of distinctive fruit quality parameters. The concentrations of polyphenols and amino acids in the berries were highly related to the amount of received solar radiation. Vineyard terraces were able to mitigate weather extremes. However, younger vines planted at the outer end of the terrace platform showed high drought stress responses across all experimental years. However, this lessened as the vine age progressed.
The modern terracing of steep slope vineyards proved to be an appropriate tool for high-quality grape production. Additionally, the potential for promoting biodiversity through a sustainable management of the terrace embankments complements the overall positive findings of the present work. In the near future, the challenge to increase the competitiveness of young vines grown at steep slope vineyards to accompanying plants needs to be solved by means of viticultural, technical or breeding measures.
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.
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, Börner 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.
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.
In this doctoral thesis, the effects of moderately reduced water supply and seasonal variations was studied regarding the chemical and nutritionally relevant composition of the edible harvest organs of three different vegetable crops, i.e. cucumber fruit (Cucumis sativus L.), radish roots (Raphanus sativus L. var. sativus), and spinach leaves (Spinacia oleracea L.). The study was conducted to demonstrate putative plant-physiological alterations in their chemical composition that may be evoked by moderate water deficits during cultivation under open field conditions. The vegetable crops were selected according to differing harvest organs (leaves, roots and fruit), being cultivated during three consecutive years under open field conditions and two different water supply treatments within a randomized block design with multiple sets of six plots each. Depending on the vegetable, the provided water amount of the moderately reduced water supply treatment varied between 80-97% of the well-watered control treatment. Chapter 1 dealt with the effects of moderate water reduction of 3-20% on radish. Including one cultivation set per year and an additional set in 2016, i.e. a total of four separate sets, a dry matter-based increase of myo-inositol was observed, whereas the levels of selected minerals and trace elements like iron and manganese as well as those of phenolic compounds and glucosinolates decreased or remained unchanged upon moderately reduced water supply. Only insignificant effects of reduced water supply were seen on the levels of acylated anthocyanins, which represent a highly important commercial quality trait due to their importance for the roots’ or hypocotyls’ color. In contrast, the levels of fresh matter-related analytes were mainly enhanced by reduced water supply due to higher contents of dry matter. Thus, the overall quality of radish tubers seemed to be only marginally affected by moderate water limitation.
Similar results were observed for spinach as presented in Chapter 2. Nevertheless, reducing the total water amount by only 4-10% during cultivation led to various significant alterations in the chemical composition of the leaves. Similar to radish, higher dry matter-based levels of myo-inositol were found in spinach grown under low water reduction. Moreover, increased contents of zinc and manganese were found, while the levels of malic acid, fumaric acid, phosphate and chloride decreased upon slight water reduction in spinach dry matter. In contrast, spinach fresh matter was expectedly characterized by significantly higher contents of polyols, ascorbic acid, potassium, nitrogen, phosphorous, zinc and manganese, as well as total flavonoids and carotenoids, including nutritionally highly relevant compounds like the provitamin A-active β-carotene and the macular pigment lutein. Noteworthy, strong seasonal variations have been observed for numerous minor phytochemicals, such as for example for a series of specific flavonoids, whose contents seemed to be dependent on the respective irradiation conditions of the cultivation set.
In contrast to radish and spinach, cucumber from open field cultivation reacted differently to slightly reduced water supply, as summarized in Chapter 3. When cucumber fruits obtained from plants received 85-90% of the total water amount of the control treatment, they exhibited significantly higher levels of malic acid, calcium, and magnesium, while those of phosphate, phosphorous, nitrogen, and iron decreased based on dry matter. Fruit dry matter-content did not significantly change due to moderate water restriction, and, as a result, the concentration of most analytes tended to decrease in the cucumber fresh matter when grown under reduced water supply. The chemical analyses of single cucumber fruit compartments (exocarp, mesocarp and endocarp) from fruits grown under 60% of the full supply in a separate greenhouse experiment confirmed that malic acid, certain minerals and trace elements, as well as carotenoids like the most abundant lutein were relatively sensitive to moderate water reduction.
Altogether, a moderately reduced water supply was shown to significantly alter the chemical composition of the aforementioned vegetable crops. Considering the broad range of analytes from, e.g., minerals and anions to polyols and acids to micronutrients like provitamin A, it became clear that water supply reduction as studied herein did not lead to generalizable effects such as an undesired decrease or a desired enhancement of valuable compounds. For instance, the levels of selected health-promoting constituents in the fresh matter of radish and spinach were increased, while those of the same compounds contained in cucumber did not benefit at all. Generally, the overall quality of vegetables was clearly shown to be influenced not only by water supply, but also by the interaction with other abiotic factors, especially when cultivation took place in open field. Further study in the future should target interactions of moderately reduced water supply situations with changes in other abiotic factors, such as elevated CO2 concentrations.
Physiological storage disorders cause significant economic losses in a number of commercially important pome fruit varieties worldwide. Under the same storage conditions with the same cultivar, the incidence and frequency of disorders may vary in different years in a manner that must be explained by an interaction of pre-harvest and post-harvest factors. Major factors known to influence disorder incidence include annual weather pattern, management in the orchard, such as leaf-fruit ratio, calcium content of the fruit, harvest date and storage conditions. So far, the occurrence of the disorders cannot be predicted with certainty, and thus to adapt the management in the orchard or in the storage facility accordingly. Analysis of large amounts of data using Artificial Intelligence (AI) offers new opportunities to link large data sets into a meaningful context. The aim of the present work is the small-scale and non-destructive monitoring of fruit development in orchards under the above mentioned management practices. AI prediction models were created for the cultivar 'Braeburn'. 'Braeburn' is most susceptible to physiological storage disorders which cause browning in the fruit tissue below the skin. With tent-like constructions over the fruit trees, in which the temperature was controlled during two fruit physiologically important periods (petal drop to T-stage, three weeks before harvest), the temperature influence on disorder incidence was investigated. To the best of our knowledge, this was the first time that different temperature profiles could be generated in the orchard for mature 'Braeburn' trees. Thereby a positive influence on the reduction of internal browning caused by warm night temperatures (>10°C) before harvest was observed. Overall, each trial year showed different occurrences of physiological disorders. Orchard management and weather conditions resulted in significantly different fruit growth patterns and optical non-destructive point spectroscopy. The bi-weekly spectroscopy measurements on the same fruit and subsequent use in Partial Least Square Regression (PLSR) models were tested for their informative value. Additionally, the future fruit state was predicted in models based on weather data. The statistical evaluation of three years of data showed that the number of destructive soluble solids content (SSC) samples required to be collected each year for the {PLSR} models with an acceptable error rate was 100. These samples in particular needed to include the range of low and high SSC values. An unbalanced laboratory error of 0.1-1.0 °Brix had no influence on the modeled SSC values. Compared to destructive SSC determination in the laboratory, SSC could be non-destructively determined with an average deviation of 0.5 °Brix. Field measurements after a rain event had no influence on visible spectral indices. However, orchard covers such as rain protection over the fruit trees led to lower water absorption values at 975 nm. The separation of data on a tree-sector level in this work was performed manually, but initial steps were taken to display fruit growth and spectroscopy data via GPS signal location within a map. The acquisition of small-scale data at the tree-sector level revealed significant differences for SSC, chlorophyll and anthocyanin indices as well as significant differences in the incidence of physiological disorders. In future research and modeling approaches the tree sector information should be taken into account, even if this is not yet feasible to implement in a completely automated system under the given circumstances. The prediction models for the development of physiological disorders (core browning, cavities) were able to predict with two years of data the development of the disorders in the storage and the fruit flesh firmness at harvest 90 % correctly. Further research using non-destructive fruit measurements in orchards and the influence of weather conditions will provide further insights into apple quality improvement.
Im Rahmen dieser Arbeit wurde ein Modell zur Kosten- und Margenanalyse deutscher Weingüter entwickelt und angewendet, mit dem die Kosten- und Margenstrukturen deutscher Weingüter systematisch und umfassend sowie auf der Grundlage empirischer Betriebsdaten bis auf die Ebene der einzelnen Kostenträger (Weine) und Absatzsegmente (Kundengruppen) der Weingüter analysiert wurden. Aus der Sicht der Forschung schließt diese Arbeit eine Forschungslücke, denn die Kosten- und Margenstrukturen sowie die wesentlichen Kostentreiber deutscher Weingüter wurden in dieser Arbeit erstmals betriebsübergreifend auf der Ebene differenzierter Kostenträger (Weine) und Absatzsegmente (Kundengruppen) sowie auf der Grundlage empirischer Betriebsdaten mit wissenschaftlichen Methoden analysiert. Den untersuchten Weingütern wurden die Analysen auf einzelbetrieblicher Ebene zur Verfügung gestellt. Damit erhalten die Weingüter Informationen über die Höhe und die Zusammensetzung der Herstellungskosten ihrer einzelnen Weine, über die Vertriebskosten sowie über die Margen der Weine unter Berücksichtigung der verschiedenen Absatzsegmente. Für die Weingüter wird dadurch ersichtlich, welche Weine und welche Absatzsegmente zum betrieblichen Erfolg beitragen und in welchen Bereichen Handlungsbedarf besteht.
Basierend auf der Wertschöpfungskette der Weinproduktion und -vermarktung wurden dazu zunächst die Betriebsbereiche der Weingüter voneinander abgegrenzt und es wurden spezielle Anforderungen dieser Betriebsbereiche an die Entwicklung und Umsetzung des KMA-Modells für Weingüter definiert. Aufbauend auf diesen Anforderungen wurde ein Grundkonzept des standardisiert anwendbaren KMA-Modells entwickelt und vorgestellt.
Das KMA-Modell umfasst einerseits einen Input-Bereich, in den die betriebsspezifischen Aufwendungen der Gewinn- und Verlustrechnung sowie das betriebsspezifische Anlagevermögen der Weingüter übernommen werden. Darüber hinaus erforderliche Daten zur Kosten- und Margenanalyse werden über ein betriebsspezifisches Erhebungsblatt (eine MS Excel Tabelle) auf einzelbetrieblicher Ebene erfasst und in das KMA-Modell als Input überführt. Im Bereich der Berechnungen werden zunächst neutrale Aufwendungen abgegrenzt und die Kostenarten der Weingüter werden auf der Grundlage der Input-Daten ermittelt. Die Kostenarten werden dabei über mehrere Ebenen nach den Betriebsbereichen Weinbau, Kellerwirtschaft, Verwaltung, Vertrieb und Sonstiges untergliedert. Das Ergebnis der Kostenartenrechnung sind pagatorische (aufwandsgleiche) und wertmäßige (kalkulatorische) Kosten von Weingütern, denen spezifische Ressourcen zur verursachungsgerechten Kostenverrechnung zugeordnet werden.
Der Kern des KMA-Modells ist die verursachungsgerechte Kostenverrechnung der Teilbereiche Weinbau, Kellerwirtschaft, Verwaltung, Vertrieb und Sonstiges. In den Bereichen Weinbau und Kellerwirtschaft werden im Rahmen der Verrechnungen zunächst Kostenträger-Einzelkosten auf die Kostenträger (Weine) zugeordnet. Im Bereich Weinbau sind dies i.W. Pacht- und Pachtbewirtschaftungskosten für bestimmte Weinberge, Kapitalkosten für den Grund und Boden der Weinberge sowie Abschreibungen und Kapitalkosten für die Rebanlagen der Weinberge, welche nach verschiedenen Bewirtschaftungs- und Erziehungsformen differenziert verrechnet werden. Als kellerwirtschaftliche Kostenträger-Einzelkosten werden insb. Kosten für den Zukauf von Trauben, Most und/oder Fasswein, Kosten für die Flaschenausstattung (Kosten für die Flasche, den Verschluss, das Etikett, ggf. eine Zusatzausstattung und die Verpackung) sowie Kapitalkosten für das in den produzierten Weinen gebundene Kapital bis zum Verkauf der Weine verrechnet. Im darauffolgenden Schritt werden die Kostenträger-Gemeinkosten über ressourcenspezifische Kostentreiber aufgespalten und nach Prozessen sowie Aktivitäten verrechnet. Im Bereich Weinbau werden diese Verrechnungen nach Bewirtschaftungs- und Erziehungsformen und im Bereich Kellerwirtschaft nach Gebindearten und -größen während des Weinausbaus der Kostenträger (Weine) differenziert. Bei den Verrechnungen über die Prozesse und Aktivitäten wird eine Vielzahl an Kostentreibern angewendet, damit modellseitig eine möglichst verursachungsgerechte Kostenverrechnung sichergestellt wird. Im Bereich Weinbau sind dies bspw. die Arbeitskraftstunden je ha je Aktivität sowie die Maschinenstunden je ha je Aktivität in Abhängigkeit unterschiedlicher Bewirtschaftungs- und Erziehungsformen der Weinberge, die zur Erzeugung bestimmter Weine verwendet werden. Als Kostentreiber des Betriebsbereichs Kellerwirtschaft werden modellseitig i.W. die Kostentreiber Arbeitskraftstunden je 1.000 l je Aktivität sowie die benötigten Maschinenstunden je 1.000 l je Aktivität in Abhängigkeit unterschiedlicher Gebindearten und -größen während des Ausbaus der Weine angewendet. Bestimmte Kostenarten der Betriebsbereiche Weinbau und Kellerwirtschaft werden vereinfacht über sonstige Verrechnungen auf die Kostenträger (Weine) geschlüsselt. Auch für die Kostenverrechnungen des Betriebsbereichs Vertrieb werden ressourcenspezifische Kostentreiber zur verursachungsgerechten Schlüsselung der Vertriebskosten auf die Absatzsegmente des KMA-Modells angewendet. Dies sind u.a. erbrachte Arbeitskraftstunden der Arbeitskräfte je Absatzsegment zur Schlüsselung der Personalvertriebskosten, verschiedene Versandarten und -mengen zur Schlüsselung der Versandkosten sowie flächenmäßige Anteile der Nutzung von Gebäuden für vertriebliche Zwecke zur Schlüsselung von Gebäudekosten. Anschließend werden die Kosten der Absatzsegmente auf die Kostenträger (Weine) verrechnet, die über die jeweiligen Absatzsegmente verkauft werden. Die Kosten der Betriebsbereiche Verwaltung und Sonstiges werden vereinfacht über sonstige Verrechnungen auf die Kostenträger (Weine) geschlüsselt. Der letzte Berechnungsschritt des KMA-Modells ist die Margenkalkulation der Kostenträger (Weine) nach den Absatzsegmenten (Kundengruppen) des KMA-Modells. Dabei werden die Kostenträger-Selbststückkosten der Weine unter Berücksichtigung der Absatzsegmente von den Verkaufspreisen der Kostenträger (Weine) je Absatzsegment subtrahiert.
Die Anwendung des KMA-Modells in 22 deutschen Weingütern zeigt, dass Personalkosten (33 %), Materialkosten (23 %) und Kapitalkosten (20 %) in der Summe 76 % der Gesamtkosten im Mittel der untersuchten Weingüter ausmachen. Auf der Ebene der Betriebsbereiche (Kostenstellen) entfallen im Mittel der untersuchten Weingüter zwei Drittel der Gesamtkosten auf die Betriebsbereiche Weinbau (37 %) und Kellerwirtschaft (30 %). 20 % der Gesamtkosten entfallen auf weinbauliche Prozesse und Aktivitäten sowie 14 % der Gesamtkosten auf kellerwirtschaftliche Prozesse und Aktivitäten.
Die Höhe der Prozesskosten je ha im Betriebsbereich Weinbau hängt wesentlich von den unterschiedlichen Bewirtschaftungs- und Erziehungsformen ab, in denen die Weine erzeugt werden. Wesentliche Treiber für die Unterschiede der weinbaulichen Prozesskosten je ha zwischen den Bewirtschaftungs- und Erziehungsformen sind die Prozesse Rebschnitt, Pflanzenschutz, Begrünungsmanagement und Traubenlese. Je Liter betrachtet wirkt sich der Hektarertrag der Weine wesentlich auf die weinbaulichen Prozesskosten der Weine aus, denn die empirischen Untersuchungen dieser Arbeit ergeben, dass die weinbaulichen Prozesskosten der untersuchten Weine bei einer Steigerung des Hektarertrags um 1.000 l / ha um rd. 0,30 € / l abnehmen.
Kellerwirtschaftliche Prozesskosten entfallen im Mittel der untersuchten Weingüter größtenteils auf die Verarbeitungsstufe „Mostverarbeitung und Ausbau zum Jungwein“. Die empirischen Untersuchungen zeigen, dass die kellerwirtschaftlichen Prozesskosten der Weine, welche in Barriquefässern ausgebaut werden, um rd. 2,34 € / l signifikant höher ausfallen, als die kellerwirtschaftlichen Prozesskosten der Weine, welche in Edelstahltanks ausgebaut werden. Darüber hinaus hat die durchschnittliche Gebindegröße der Gebinde, in denen die Weine ausgebaut werden, einen signifikanten Einfluss auf die Höhe der kellerwirtschaftlichen Prozesskosten der Weine. Aus den Untersuchungen geht hervor, dass die kellerwirtschaftlichen Prozesskosten der untersuchten Weine bei einer Erhöhung der durchschnittlichen Gebindegröße während des Weinausbaus um 1.000 l je Gebinde um 0,10 € / l abnehmen.
Die Höhe und die Zusammensetzung der Vertriebskosten der untersuchten Weingüter hängt wesentlich von den Absatzsegmenten ab, über welche die Weine verkauft werden. Die Vertriebskosten der Absatzsegmente Privatkunden und Gastronomiekunden liegen im Mittel der Weingüter mit 1,67 € / Fl. bzw. 0,92 € / Fl. über den Vertriebskosten der übrigen Absatzsegmente. Die Unterschiede der Vertriebskosten zwischen den Absatzsegmenten ergeben sich i.W. aus dem variierenden Einsatz von Personal, Werbe- und Versandmaßnahmen sowie Gebäuden in Abhängigkeit der Absatzsegmente.
Im Rahmen der Arbeit wurden insgesamt 686 Kostenträger (Weine) mit dem KMA-Modell ausgewertet. Deskriptiv betrachtet zeigt sich dabei, dass relativ hochpreisige Weine im Vergleich zu relativ niedrigpreisigen Weinen im Mittel der untersuchten Weingüter i.d.R. höhere Herstellungs- und Selbstkosten aufweisen. Trotz der höheren Herstellungs- und Selbstkosten erzielen die relativ hochpreisigen Weine im Vergleich zu den relativ niedrigpreisigen Weinen in der Tendenz (deskriptiv betrachtet) allerdings höhere Margen je Liter sowie höhere prozentuale Margen auf Selbstkosten. Vor diesem Hintergrund wurden die Steigerungen der prozentualen Margen der Weine in Abhängigkeit der Verkaufspreise der Weine unter Berücksichtigung der unterschiedlichen Absatzsegmente detailliert in einem Regressionsmodell untersucht. Aus den Untersuchungen mit diesem Regressionsmodell geht hervor, dass die untersuchten Weine bei einem Verkauf über die Absatzsegmente Privatkunden und Gastronomiekunden mit einer Steigerung des Verkaufspreises um einen € je Liter um rd. 3,2 % höhere Margen erzielen. Etwas geringer fällt die Steigerung der Margen der Weine in Abhängigkeit der Verkaufspreise in den Absatzsegmenten Fachhandelskunden und Großhandelskunden aus, denn mit einer Steigerung des Verkaufspreises um einen € je Liter steigen die Margen der Weine im Vergleich zu den Absatzsegmenten Privatkunden und Gastronomiekunden nur um rd. 2,3 % bzw. 2,6 %. Die Margen der Weine mit einem Referenzpreis von 2 bis < 4 € / l liegen bei einem Verkauf über die Absatzsegmente Privat-, Gastronomie-, Fachhandels- und Großhandelskunden zwischen - 4 % und 2 %. Zusammenfassend und überbetrieblich bleibt deshalb festzuhalten, dass Weine der untersuchten Weingüter mit einem Referenzpreis von 2 bis < 4 € / l sowie darunter kaum vollkostendeckend sowie mit positiven Margen verkauft werden können.