Browsing by Subject "Qualität"

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Agricultural education in Honduras : return on investment, quality, and efficiency
(2020) Flores Rios, Maria Delfina; Knierim, Andrea
The Agri-food sector, like any other economic sector, requires competent workers and entrepreneurs able to maximize productivity and cope with the various challenges the sector is facing. Agricultural education prepares these actors to acquire knowledge, identify options that optimize their productivity, and adapt to changing environments. However, the importance of agricultural education is declining in education policies, and nowadays, it is no longer an attractive field of study for the youth. There is a need to re-invent agricultural careers to the new demands of the agri-food and labor market sectors. As there is a limited number of studies available that analyze agricultural education in Latin-American and other developing countries, this research provides new insights by examining the determinants for return to investment, quality, and efficiency of agricultural education, taking Honduras as a case study. The present dissertation encompasses three interrelated studies. The first study addresses the research question on how the educational attainment on agricultural education, years of experience, age, sex, geographical region of residence, and work sector, affect the graduates earnings. This study computes the return to agricultural education by educational level, using several econometric techniques, such as the instrumental variables, Heckman’s two-step procedure, and the multinomial logit to tackle endogeneity of education, sample selection bias, and selection bias for choosing this field of study, respectively. The results show that regardless of the economic activity in which the individuals work, graduates from agricultural educational programs receive positive returns on their investment in education. High school graduates from these programs, have higher earnings within the economic activity of agriculture than non-graduates. At the university level, the graduates competencies are better paid in economic activities outside agriculture than inside, for example, in fields of manufacturing, public administration, and education. The second study addresses the question of what competencies employers require from graduates of agricultural education programs. Interviews and workshops were conducted, addressing employers from agricultural value chains, purposely selected, and using maximum variation sampling. The results show that graduates perform at an intermediate level in technical competencies. Of the 20 competencies identified, graduates perform poorly in at least six areas of competence, which requires immediate action. Although the analysis of academic curricula shows that the competencies included are relevant for employers to cope with the challenges faced by the agri-food sector, there is room for improvement. Finally, the third study addressed the question about the level of efficiency of the public institutions delivering agricultural educational programs, and the factors influencing it. This study computes the efficiency using the non-parametric approach data envelopment analysis (DEA). The model used is output-oriented, variable return to scale, and two-stage where controllable and non-controllable inputs are included in the first and second stages, respectively. This study follows a double bootstrapping procedure to avoid the caveats of the conventional DEA analysis. The evidence showed that none of the agriculture education centers in the sample is considered a full efficient entity. However, there is a potential to improve the usage of the current resources. It is possible by expanding the outcomes in a range of 1% to 50% without changing the existing resources. In summary, the findings of this dissertation provide compelling evidence that each additional level of agricultural education in Honduras is a worthwhile investment, and that graduates from both education levels, secondary and tertiary levels, are necessary to support Honduras economy. Nevertheless, improvements should be made in terms of the quality and the resources used in the provision of agricultural education. Based on the research findings, it is recommended to revise the academic curricula, with the aim of better matching education and labor market requirements. Secondly, a closer analysis of the implementation of the educational processes is necessary in order to enhance the competencies requested and identify better management of the resources available. Finally, setting formal collaboration mechanisms between the education centers, authorities, and the private sector could strongly improve agricultural education systems’ contribution to the performance of the sector. To further refine this research, it would be beneficial to increase the sample sizes to expand further the techniques used.
Breeding winter durum wheat for Central Europe : assessment of frost tolerance and quality on a phenotypic and genotypic level
(2015) Sieber, Alisa-Naomi; Würschum, Tobias
Durum wheat (Triticum durum) is a tetraploid wheat that is used for pasta and other semolina products. Quality standards for semolina requested by the pasta industry are very high. Different characteristics should come with the cereal as raw material for an optimal end product. Vitreosity, the glassy and amber quality feature of durum wheat kernels, is an indicator for high semolina yield. The complex protein-starch matrix of glassy kernels breaks the grain into the typical semolina granulate instead of flour during milling. Humid conditions, like late summer rains in Central Europe, have a huge effect on this characteristic, changing this matrix irreversibly. Such processes in the kernel are less understood and challenge plant breeders to find genotypes with improved vitreosity. A set of F5 winter durum wheat lines (Chapter 2) was used to investigate the relationship between protein content and vitreosity as well as the impact of humidity on the stability of the trait. A method to evaluate the mealy part in kernels was improved and enabled to test for the influence of humidity on vitreosity. Furthermore, it was revealed that the vitreosity of a durum wheat kernel depends on the protein content up to a specific threshold as well as on the genotypic potential to form the complex endosperm matrix. The ability to maintain this kernel quality under humid conditions also highly depends on the genetics of a variety. In the Mediterranean region, durum wheat is grown as autumn-sown spring type. The mild winters as well as rain during spring allow the plants to develop well, and the dry summers enable an early harvest in June. Durum wheat production in Central Europe, on the other hand, is confronted with harsh winters and recurring severe frosts. The lack of a sufficient frost tolerance in combination with high quality, forces farmers to use the spring type with a spring sowing. Growing winter durum instead of spring durum wheat, would allow an autumn sowing. Using the winter type in this growing area, could have several advantages like an increased yield and stability due to a prolonged growing time. Further, the constant soil coverage would prevent soil erosion and the growth vigor of winter durum has advantages against weeds. The success of winter durum breeding depends on frost tolerance as a key factor for varieties with excellent winter survival. Discontinuous occurrence of frosts across years and protective snow coverage, however, limit the phenotypic selection for this trait under field conditions. Greenhouses or climate chambers could be used as alternative to test under the necessary conditions, but those fully-controlled tests are time consuming and labor-intensive. The ‘Weihenstephaner Auswinterungsanlage’ are wooden boxes with movable glass lids used as a semi-controlled test. Plants are exposed to all seasonal conditions, including frost stresses, in this test, but they can be protected from snow coverage. While this method is already successfully used to test for frost tolerance in bread wheat, the application in durum wheat has not been evaluated yet. The frost tolerance scorings of winter durum elite lines (F5 and F6) based on the ‘Weihenstephaner Auswinterungsanlage’ were compared to the field evaluation (Chapter 3). It was demonstrated that this semi-controlled test produces reliable and highly heritable (h2 = 0.83-0.86) frost tolerance data. The correlation of those results compared with the field data (r = 0.71) suggests this semi-controlled test as an indirect selection platform. Since it is now possible to test cost-efficient at early stages for frost tolerance, the next challenge was to determine whether the kernel quality or the grain yield suffers from an increased frost tolerance. In a survey with F5 winter durum elite lines, no negative association between frost tolerance and quality or other important agronomic traits could be found in European breeding material (Chapter 4). In order to support classical plant breeding, which relies predominantly on phenotypic data and parental information, molecular markers can be taken into account. Molecular markers can provide an in-depth look into the genetic architecture of traits, enable the determination of the relatedness of genotypes, identify the genetic variation in a population, or can assess the effect of geographic selection preferences. Furthermore, it is possible to assist knowledge-based selection. This improves plant breeding programs on a genetic level. The population structure in spring durum has already been examined with molecular methods in several studies. Winter durum, on the other hand, was only analyzed as a small group as part of spring durum studies or in groups of landraces. A highly diverse and unique panel of 170 winter durum and 14 spring durum lines was analyzed using a genotyping-by-sequencing (GBS) approach. A total of 30,611 markers, well distributed across the chromosomes, were obtained after filtering for marker quality. A principal coordinate analysis and a cluster analysis were applied. Together they revealed the absence of a major population structure (Chapter 5). The lines, however, grouped in a certain way, depending on their origin, associated with decreasing quality and increasing frost tolerance moving from South to Continental Europe. These groups allow breeders to conduct targeted crosses to further improve the frost tolerance in the Central European material. Another possibility is to build heterotic groups for hybrid breeding. The linkage disequilibrium (LD) decay was within 2-5 cM, indicating a high diversity in winter durum. The high marker density together with the extent of LD observed in this analysis allows to perform high-resolution association mapping in the present winter durum panel. The 30,611 markers and additional markers for candidate genes in frost tolerance were used to assess the genetic architecture of frost tolerance in durum wheat (Chapter 6). A major QTL was identified on chromosome 5A, likely being Frost Resistance-A2 (Fr-A2). Additional analysis of copy number variation (CNV) of CBF-A14 at Fr-A2 support this conclusion. CBF-A14 CNV explains about 90% of the proportion of genotypic variance. Two markers found in the QTL region were combined into a haploblock and enabled to capture the genetic variance of this QTL. Furthermore, the frequency of the QTL allele for frost tolerance shows a latitudinal gradient which is likely associated with winter conditions. In summary, the selection tools for vitreosity and frost tolerance provided in this study create a platform for winter durum breeding to select for high quality genotypes with excellent winter survival utilizing phenotypic as well as genotypic information.
Charakterisierung der Qualität von Blütenpollen in unterschiedlichen Regionen Baden-Württembergs
(2022) Friedle, Carolin Gertrud Maria; Hasselmann, Martin
Honey bees (Apis mellifera) collect nectar and pollen from plants to feed their brood. Pollen provides a wide range of nutrients, such as proteins and lipids, but also carbohydrates, vitamins and enzymes. Because of these ingredients, pollen is also attractive to humans and is used as a dietary supplement. However, honey bees collect pollen not only from wild plants, but also from flowering crops grown in agriculture. Accordingly, contamination from plant protection products can be found in bee pollen and bee bread. In order to get a deeper insight into the occurrence and distribution of pesticide residues during an entire season, a total of 102 daily pollen samples were collected from April to July 2018 using pollen traps in an orchard in southern Germany. Almost 90% of the pollen samples showed detectable levels of pesticide residues. A total of 29 pesticides were detected in the samples, with more than half being fungicides, followed by insecticides and herbicides. Maximum concentrations of up to 4500 ng/g could be measured at the end of April. Samples collected in early May and late June also showed high levels of pesticides. A general risk management was performed to assess the risk of the detected pesticide concentrations for honey bees. The microbial quality of bee pollen is highly dependent on its botanical and geographic origin, as well as climatic conditions and post-harvest processing steps by the beekeeper. If no processing steps such as freezing or drying follow after harvest, the growth of microorganisms can be promoted and the pollen quality can be influenced by negative side effects such as fermentation or the production of mycotoxins. Bacterial and fungal colonies can be determined both by culture-dependent methods such as colony counting on plates and by culture-independent methods such as 16-rRNA amplicon sequencing. Following the hypothesis that storage conditions influence the composition of microorganisms in bee pollen, freshly harvested bee pollen was stored for seven days in June 2018 and 2019 under defined conditions (cold, room temperature, warm) and analyzed by sequencing 16S and 18S PCR amplicons. The bacterial community varied slightly between the sites studied and showed no significant difference between the storage conditions. The fungal community showed significant differences both between the studied sites and between the different storage conditions. The dominant fungal genera in the pollen samples were Cladosporium, Aspergillus and Zygosaccharomyces. While Cladosporium was most dominant in freshly collected pollen and the percentage decreased during storage, Aspergillus and Zygosaccharomyces showed a significant increase especially under warm storage conditions. Other contaminants naturally produced by plants can also have negative impacts on human health. Pyrrolizidine alkaloids belong to a group of phytochemicals, of which more than 600 structures are known in around 3% of all flowering plants worldwide. PA are known to be able to cause both acute poisoning and chronic damage or cancer in animals and humans. In July 2019, pollen was collected at 57 locations in Baden-Württemberg and analyzed for 42 different PAs and their N-oxides in order to expand knowledge about PA contamination in pollen and to be able to estimate the risk of the concentrations. A total of 22 different PAs were detected in over 90% of all samples examined. Only 5% of the PA were obtained as PA from plants of Senecio sp. identified, while 95% of PAs with a botanical background are from Echium sp. and Eupatorium sp. could be identified. The maximum total concentration of PA per sample was determined to be 48,400 ng/g. According to the risk values calculated by the BfR, however, 42% of the samples represented an increased risk to human health.
Deciphering the potential of large-scale proteomics to improve product quality and nutritional value in different wheat species
(2022) Afzal, Muhammad; Longin, Friedrich
Wheat (Triticum aestivum) is one of the most important staple crops globally, which provides on average ~20% of the dietary intake of protein, starch and further important ingredients like fiber, minerals, vitamins, and essential amino acids for humans. Besides common wheat, there exist further wheat species with global to only local importance, i.e., durum, spelt, emmer and einkorn. Common wheat and durum are relatively widely cultivated whereas the other three species are cultivated only in specific regions. Apart from other functions, wheat proteins largely influence the end-use quality of products such as bread and pasta quality. Furthermore, wheat proteins can induce inflammatory reactions in humans such as celiac disease, wheat allergy and non-celiac wheat sensitivity. Thus, proteome profiles of different wheat species and cultivars within these species are of high relevance for stakeholders along the wheat supply chain. Proteomic technology has made breakthrough advancements in the recent times capable of quantifying thousands of proteins in 1.5–2 hours. Also, the wheat reference genome has been published and extended recently. These developments are extremely helpful in studying the wheat proteome at a high resolution. However, the modern large-scale proteomics has yet neither been applied to perform comparative investigation of the proteomes of different wheat species nor to study the proteomes of different types of breads and flours nor to study its application in the context of plant breeding. Therefore, we utilized modern large-scale proteomics to fill these gaps within the framework of this PhD work. First of all, an optimized data analysis pipeline was designed to deal with big proteomics data. This was necessary to estimate a multitude of quantitative genetics parameters for each protein and perform a comparative investigation of the proteomes. Optimization included implementation of data filtering based on the quantification of a protein in a given proportion of the samples, cultivars and environments. Different tests such as test for normal distribution of each protein in the context of statistical modelling and test to check the equality of variance between groups to apply the appropriate t-test were incorporated into a semi-automated workflow. In parallel, we adjusted and improved the lab methodology to deal with hundreds of samples within a short time period. We introduced a novel hybrid liquid chromatography-mass spectrometry (LC-MS) approach that combines quantification concatamer (QconCAT) technology with short microflow LC gradients and data-independent acquisition (DIA). The proposed approach measures the proteome by label-free quantification (LFQ) while concurrently providing accurate QconCAT-based absolute quantification of the key amylase/trypsin inhibitors (ATIs). These methods were then applied to compare different wheat species based on dozens of cultivars grown at multiple locations. First, we compared common wheat and spelt and identified 3,050 proteins overall. Of total proteins, 1,555 proteins in spelt and 1,166 in common wheat were only detected in a subset of the field locations. There were 1,495 and 1,604 proteins in spelt and common wheat, respectively, which were consistently expressed across all test locations in at least one cultivar. Finally, there were 84 and 193 unique proteins for spelt and common wheat, respectively, as well as 396 joint proteins, which were significantly differentially expressed between the two species. Using potentially allergenic proteins – annotated as amylase/trypsin inhibitors, serpins, and wheat germ agglutinin – we calculated an equally weighted “allergen index” that largely varied across cultivars ranging from –13.32 to 10.88 indicating the potential to select for cultivars with favorable proteome profiles. Next, we examined the proteomes of six different flours (wholegrain and superfine flours) and 14 different bread types (yeast and sourdough fermented breads and common wheat breads plus/minus bread improver) from common wheat, spelt and rye. Proteins that could cause allergies were functionally classified and comparatively measured by LFQ in flours and breads. Our findings showed that allergenic proteins were more prevalent in common wheat and spelt than rye and were not specifically degraded during bread manufacturing. In terms of abundance of the allergenic proteins, there was almost no difference between spelt and common wheat and the type of grain is likely more important for allergenicity than milling or traditional fermentation techniques. In a further study, we generated the flour reference proteomes for five wheat species, identifying at least 2,540 proteins in each species. More than 50% of the proteins significantly differed between species. Particularly, einkorn expressed 5.4 and 7.2 times less allergens and amylase/trypsin inhibitors than common wheat, respectively, emerging as a potential alternative cereal crop for people with sensitivities to cereal allergens. Lastly, we studied the application of large-scale proteomics for plant breeding. We found a significant impact of the environmental factors on protein expression. Only a fraction of proteins was stably expressed in all environments in at least one cultivar. Environmental influence was observed not only in the form of absolute expression or suppression of a certain protein at one or more environments but also in the form of low heritability (H2). High coefficients of variation across wheat cultivars indicate that the protein profiles of different cultivars vary considerably. Although, heritability was low for many proteins, we were able to identify hundreds of proteins with H²>0.5 – including key proteins for baking quality and human health. It should be possible to specifically manipulate the expression of functionally important proteins with high heritability by selecting and breeding for superior wheat cultivars along the wheat supply chain. Nevertheless, a successful implementation in plant breeding programs needs an improvement in the speed of protein quantification methods and in the validation of protein functions and annotations. In a nutshell, high number of proteins can be quantified in cereal grains utilizing cutting-edge proteomics techniques, opening new avenues for their use in the wheat supply chain. We generated lists of intriguing candidate proteins for further investigations on wheat sensitivity, and proteins with high heritability and important biological functions. Current research work has significant implications for the scientific and business communities across multiple disciplines including breeding, agriculture, cereal technology, nutritional science, health, and medicine. Political decision-makers and stakeholders in the food supply chain can benefit from the findings of this PhD project.
Does regulation trade-off quality against inequality? : The case of German architects and construction engineers
(2018) Strohmaier, Kristina; Rostam-Afschar, Davud
We exploit an exogenous price increase by about 10% for architectural services to answer the question how price regulation affects income inequality and service quality. Using individual-level data from the German microcensus for the years 2006 to 2012, we find a significant reform effect of 8% on personal net income for self-employed architects and construction engineers. This group moved from the second lowest to the highest quintile of the net income distribution. This increase in inequality is associated with a deterioration of service quality. The reform reduced average scores of a peer ranking for architects by 18%.
Evaluierung des Qualitätszeichens Baden-Württemberg (QZBW) aus der Sicht der Teilnehmer
(2015) Hauck, Manuel; Becker, Tilman
Im Zuge einer Befragung der Universität Hohenheim wurde die Teilnahme am Qualitätszeichen Baden-Württemberg (QZBW) und weiteren Qualitätsstandards, wie QS und IFS untersucht. Dazu wurden zwei Fragebögen ausgearbeitet, die zum einen an die Zeichennutzer des QZBW und zum anderen an die Nicht-Zeichennutzer gerichtet waren. Die Befragung erfolgte vom 2.2.2015 bis zum 6.3.2015. Angeschrieben wurden Betriebe der Ernährungsbranche aus den Sektoren Obst, Gemüse und Kartoffeln, Fruchtsaft, Fleisch und Bäckerhandwerk. In den Sektoren Obst, Gemüse und Kartoffeln wurden unter anderem Direktvermarkter und Großhändler befragt, in der Fleischwirtschaft unter anderem Metzgereien und Schlachtereien. Aus den Ergebnissen der Umfrage wird deutlich, dass auf der einen Seite mögliche Marketing-Vorteile und auf der anderen Seite die Anforderungen der Abnehmer die bedeutendsten Gründe für die Zertifizierung nach QZBW sind.
Fertilizer quality and its impacts on technical efficiency and use intensity in the North China Plain
(2014) Khor, Ling Yee; Zeller, Manfred
There has been a significant increase in agricultural output in the past 50 years. A major factor of this growth is the rise in input use such as fertilizer, especially during the beginning of this period. However, the trend is not uniform throughout the world. Even though there are still regions where fertilizer can contribute greatly to the increase in yield, this input is so overused in some other places that its marginal productivity is no longer significant. In this case, not only is it a waste of valuable resources, it also leads to environmental degradation and pollution that is detrimental to human health. To make matters worse, the quality of the agricultural input itself has been of increasing concern lately. It includes problems such as normal seed being sold as hybrid seed, pesticide that is mixed with less effective chemicals, or fertilizer which contains less nutrient than that labeled on the package. We focus our research on the North China Plain, a region with both fertilizer overuse and fertilizer quality problems. The issue of low fertilizer quality is however not confined to this region only, as recent news reports have indicated that substandard or fake agricultural input is a problem in other countries as well, for example Bangladesh, Cambodia, Nigeria, Tanzania, and Vietnam. In addition, although the analysis presented in this dissertation concentrates on fertilizer, some of the methodology can also be extended to examine the impact of other agricultural inputs with questionable quality, such as seed and pesticide. The main theme of our study is split into three subtopics: efficiency, wealth effect, and use intensity, with each of them focusing on a different aspect of the impact from low quality fertilizer. The main contribution of this dissertation is that despite the widespread problem of fertilizer quality, we believe we are the first to examine its impact both theoretically and empirically on efficiency and use intensity. The theoretical contribution includes deriving the bias that exists if one were to ignore the quality aspect in the estimation of production functions and technical efficiency, especially if the research area is located at one of the places with fertilizer quality problems, such as China and the other affected countries. We also provide a theoretical framework that reconciles the different findings in the literature on the direction of wealth effect on fertilizer use. It offers a consistent explanation on why the wealth effect can be different when we are looking at regions or farmers of different wealth levels. Empirically, the dissertation quantifies the magnitude of estimation bias in input elasticity and technical efficiency in our research region of North China Plain. It also supports our theoretical derivation and shows that the direction of wealth effect is not fixed across farmers of different wealth levels. Finally, the integration of fertilizer testing into a household survey allows us to look closer at the link between perceived and true fertilizer quality, as well as how they affect the fertilizer use intensity of the farmers. The worsening fertilizer quality issue in the North China Plain is of great concern because - as this dissertation research shows - it leads to an increase in fertilizer use, which is already excessive in the area. This is not only a waste of valuable resources reducing economic efficiency but also causes environmental and health problems, e.g. through pollution of ground water. The currently implemented policy of subsidizing the fertilizer manufacturers is a double whammy in this regard because by keeping the price of the product low, it encourages the usage of an input that is already overused. It also makes the quality control of the fertilizer in the market more difficult, with the presence of so many small scale producers that are inefficient. In view of these deficiencies, it would be better to shift the policy focus from price reduction to quality improvement. A suggestion is to facilitate the award of quality labels to satisfactory products with regular third-party testing of the fertilizer to ensure that its quality does not deteriorate after receiving the label. The honest producers in the industry could also help set up a sector-wide monitoring body to prevent their image from being tarnished by the less responsible manufacturers. An additional recommendation is to increase the resources and staff available to extension service in order to increase the information flow between policymakers and farmers.
Genetic architecture of quality traits in wheat
(2021) Rapp, Matthias; Longin, Friedrich
Quality traits in wheat are of great importance, as they are required for the production of a wide range of food products. In Europe, bread wheat (Triticum aestivum ssp. aestivum) for human consumption is primarily used in pastries. For durum wheat (Triticum turgidum ssp. durum) that is used almost exclusively for pasta production, quality traits are at least as important as in bread wheat. In Central Europe, the bread wheat subspecies spelt (Triticum aestivum ssp. spelta) is characterized by a different quality compared to bread wheat. In addition, it is produced for a niche market with a particular focus on the final product quality. The high number of demanded quality traits of a wheat variety represents a great challenge for wheat breeders. Thus, knowledge about the genetic architecture and interrelation of quality traits is of high value for wheat breeding. Due to the long list of quality traits in wheat, we focused on currently important quality traits in each of the three wheat species. In durum wheat, I was interested in traits with a high importance for durum millers and pasta producers. The protein content and the sedimentation volume are of high importance for pasta producers as they influence the firmness of cooked pasta, better known as “al dente”. A low falling number may lead to brown instead of light yellow pasta, which goes back to an increased maillard reaction during pasta production and drying. The vitreousity, representing the glassy appearance of durum grains, and the thousand kernel mass influence the semolina yield and are therefore of great interest for durum millers. In the genome-wide association mapping, I identified several putative QTL for these quality traits. For the sedimentation volume, a genomic region on chromosome 1B appeared to be important. A BLAST search against the reference genomes of emmer and bread wheat revealed the Glu-B3 gene as a likely candidate. For vitreousity, genomic regions on chromosome 7A explained a larger proportion of the genotypic variance. One of these QTL, possibly related to the Pinb-2 locus, also slightly influenced the protein content. Thus, this genomic region might be a genomic reason for the positive correlation between vitreousity and protein content. For TKM we detected a putative QTL, which explained a large proportion of the genetic variance, but could not be attributed to a known gene. Besides a good performance for quality traits, a modern durum wheat variety should be complemented by a good agronomic performance, in particular a high grain yield. This poses a great challenge for plant breeders, since grain yield and protein content are negatively correlated. With regard to simultaneously improving grain yield and protein content, the protein yield or the grain protein deviation (GPD) were proposed. We evaluated those and further selection indices for their potential to be utilized for the simultaneous improvement of grain yield and protein content. Our results indicated that a simultaneous improvement of the two traits grain yield and protein content by means of an index seems possible. However, its efficiency largely depends on the weighting of the single traits. The selection for a high GPD would mainly increase the protein content whereas a selection based on protein yield would mainly improve the grain yield. Nevertheless, a combination of different indices allows balancing this selection. Compared to the primary traits grain yield and protein content, the selection indices did not essentially differ in the complexity of their genetic architecture. In bread wheat, we focused on the acrylamide precursor asparagine. Acrylamide is formed in potentially harmful concentrations when cereals are treated with high temperatures over a long period during the processing to food products. A promising strategy to reduce the acrylamide formation would be to decrease the precursors in the raw material. The wide range of variation for asparagine content showed that variety selection might have a large influence on the occurrence of acrylamide in the final product. In addition, the moderately high heritability suggested that successful breeding for lower asparagine content is possible. This conclusion is supported by the observation of no strong negative correlations between asparagine content and a number of other important traits. The genome-wide association mapping resulted in the detection of eight putative QTL, which jointly explained 78.5% of the genetic variance. A putative QTL on chromosome 7B explained with, 18.4%, the highest proportion of the genetic variance for a single marker. For spelt wheat, we assessed a high number of quality traits but placed a special emphasis on the flavor and odor of bread produced from 30 different varieties. Interestingly, we observed a significant genetic variation for bread flavor and a heritability estimate of moderate magnitude. This suggests that even for bread flavor a successful selection appears possible. Taken together, for most traits the genome-wide association mapping resulted in the detection of a high number of putative QTL. This indicates a complex genetic architecture, typical for predominantly quantitatively inherited traits. However, few of the putative QTL explained a large proportion of the genetic variance, so that they might have the potential to be used in marker-assisted selection. In order to examine the potential of genomic selection, I performed a five-fold cross validation for the different quality traits. I could confirm previous findings that the integration of QTL information as fixed effects in the genomic prediction model increased the prediction abilities considerably. The average prediction abilities for most traits suggested a high potential for genomic selection in breeding programs. In conclusion or results form a good basis for further research but more importantly already deliver valuable knowledge that can be used as guideline to advance wheat breeding programs for improved quality.
Management of Fusarium graminearum-inoculated crop residues : effects on head blight, grain yield and grain quality of subsequent winter wheat crops
(2001) Yi, Cuilin; Aufhammer, Walter
On the experimental station Ihinger Hof of Hohenheim University field experiments with artificial inoculation were conducted. An isolation-strip experiment included strips of winter rape crops, separating non-inoculated test plots of wheat from inoculated wheat plots. For the main field experiment, maize or spring wheat were planted as pre-crops in rotations with winter wheat and different crop residue treatments were applied. Additional residue management greenhouse tests were conducted and treated equivalent to the field experiment. Results of isolation-strips field experiments with wheat showed that. Isolation strips of 2 m width reduced disease incidence on neighbour plots by more than 50%. A further increase in isolation strip width did improve the isolation effect, but the differences between isolation strip widths were comparatively small. The infection in test plots was not completely eliminated even with 8 m wide strips. Greenhouse tests of residue management showed that deeper residue incorporation effectively reduced the F. g. populations on residues. The application of nitrolime reduced the population level of F. g. On the contrary, fertilization with calcium ammonium nitrate promoted F. g. populations. Soaking the residues in a fungicide preparation eliminated F. g. on the residues completely. Residue management field experiments with artificial inoculation of pre-crops, there were no significant differences in infection level after either maize or wheat, and the infection level of winter wheat was especially high after maize for silage use in one year. The reductions of FHB incidence due to ploughing or nitrolime application were 27-32% or 31-59% compared with residues remaining on the surface or calcium ammonium nitrate fertilization, respectively. But at that moderate FHB infection level, the residue management hardly influenced wheat grain yield and technological grain quality.
Profiling of physiological responses and quality aspects in Vitis vinifera L. as influenced by aspects of N application
(2019) Lang, Carina Paola; Zörb, Christian
Viticulture and the vinification of vines (Vitis vinifera L.) to wine is an important branch in agriculture world-wide. Berry quality and the associated wine quality are the driving factors here. Nitrogen (N) is the most important plant nutrient for the grapevine. In addition to its influence on vegetative and generative growth, it determines significantly the metabolite composition and the oenological parameters of the grape berry. Nitrogen is present in various forms, such as nitrate, ammonium or amino acid, in the individual plant organs and is used differently by the grapevine. Grapevines are believed to have the ability to assimilate N in various forms, which in turn may affect the quality of berries and the resulting wine. For a better understanding of the effects of N on berry and wine quality, knowledge of which N-form can be assimilated by the vine and the way that this affects oenological parameters and quality-giving metabolites is essential. To this end, several investigations were carried out at various test levels, starting with hydroponic experiments, a pot experiment and a further field experiment, and on the matured wine. The various N-forms of nitrate, ammonium, urea and the amino acids arginine and glutamine were applied, following which the plant-physiological reactions of the grapevine and quality-determining parameters in berry and wine were measured. Furthermore, a metabolite profile with a focus on phenolic components was prepared and a sensory analysis of the wine was performed. The grapevines in the hydroponics and pot experiments were treated with 4 mM total N. The grapevines in the field experiment were fertilized with 60 kg N ha-1, calculated in relation to the block size. The rootstocks SO4 and RU140 showed similar patterns of N assimilation with respect to the N-form but differed significantly with regard to the level of growth and N content among all N-forms. The N-sensitive rootstock SO4 reacted more strongly than the rootstock RU140 and, therefore, SO4 was used for further experiments. This suggests that grapevines are able to assimilate the amino acids glutamine and arginine, as also shown by the enzymatic nitrate reductase activity and the increased abundance of the transcripts of nitrate reductase and nitrite reductase. Nevertheless, the N-forms NO3- and NH4+ were preferentially assimilated. The assimilation under urea treatment was significantly reduced. In addition to the N-form, the amount of N applied had an influence on N assimilation in the grapevine. With increasing amounts, the vegetative and generative growth increased up to a threshold. However, if this threshold was exceeded, both were significantly reduced. If the grapevine is overfertilized, the sink : source ratio changes, which will lead to a change in the biomass production and furthermore to a saturation and storage of N. In addition, competition for assimilates occurs, this alters the N distribution and N availability within the plant and the berries. The N-form has no influence on berry yield. The oenological and chemical parameters of the must and the wine are of enormous importance for product quality. The key components include pH and acidity, which contribute significantly to the organoleptic properties of wine. Both factors are influenced by the N-form and the amount of N offered. As the amount of N increases, the pH increases and the acidity decreases. The N-forms NO3- and urea and, the zero application (without additional N) show the highest influences. The must weight is a defining factor reflecting the berrys maturity and thus the time of harvest. As the amount of N increases, the must weight decreases. On the one hand, an increased N amount leads to lower acidity in the berry, indicating that more sugar is being stored and that the berry is in an advanced stage of maturity. On the other hand, an increased N amount leads to a decreasing must weight, which leads further to a maturation delay. The total phenolic content increases with increasing N amount, but is highest following zero N application. Tentative phenols measured in the metabolite profile are markedly down-regulated after urea treatment and are upregulated with NO3- following NH4+ treatment. This result might arise from reduced N assimilation in the root and thus reduced N availability for the berries. The influence of N on the aroma and sensory aspects of wine is controversial. The individual aroma attributes show both an increase and a decrease in their intensity attributable to N, mainly urea and NO3-. A marked influence between N-treated vines and the zero application is also apparent. However, these contrasting results clearly show that aroma and thus the sensory characteristics of wine can be influenced both positively and negatively. The results of the aroma and sensory evaluation in the agroforestry system underline once again the controversial influence of N on the sensory features of wine; no significant influence was measured. In summary, N has a significant influence on the vegetative and generative growth of the grapevine. The influence of N can be both positive and negative and is in part directly or indirectly linked to wine quality and should therefore not be ignored.
Quo vadis? Ansätze der Qualitätssicherung von Nachhaltigkeitswettbewerben für Unternehmen
(2021) Gebhardt, Beate
This report summarises the findings of an expert workshop on "Approaches and possibilities for quality assurance of sustainability competitions", which was successfully held on 4 November 2021. The workshop was hosted by the BEST initiative at the University of Hohenheim, under the leadership of Dr Beate Gebhardt. In the workshop, together with stakeholders from practice and science, approaches for quality improvements and visualisation of high-quality standards in sustainability contests were identified and evaluated by the experts. Essential steps and research projects for the future were defined. The key results of the event are: 1.) the impact and power of sustainability competitions as potential drivers of sustainability transition is endangered (loss of significance); 2.) in order to sharpen their profile, high-quality sustainability competitions should become more visible (visualisation); 3.) the BEST initiative at the University of Hohenheim is starting a dialogue to develop criteria for high-quality sustainability competitions (orientation).
SIEGER! Business-Awards als Instrument zur Steuerung der Nachhaltigkeitstransformation : Ansätze für Qualitätssicherung und Schärfung der strategischen Weiterentwicklung
(2024-08-14) Gebhardt, Beate; Hellstern, Laura
Das von der Deutschen Bundestiftung Umwelt (DBU) geförderte Forschungsprojekt „SIEGER“ ist ein wichtiger Baustein für Überlegungen und Analysen zum Nutzen und zur Qualitätssicherung von hochwertigen Umwelt- und Nachhaltigkeitswettbewerben. Es stellt die Möglichkeiten der konzeptionellen und organisatorischen Weiterentwicklung von Nachhaltigkeitswettbewerben dar und beschäftigt sich mit Erfolg und der Zukunftsfähigkeit solcher Awards. Untersucht wurden in diesem Zusammenhang die strategische Bedeutung sowie Herausforderungen und – erstmals in diesem Kontext – der Einfluss von Krisen auf die Rolle von Umwelt- und Nachhaltigkeits-awards. Eine weitere Frage ist, ob und wie Awards die konkrete Nachhaltigkeitsperformance und -bewertung von Unternehmen bzw. einen Paradigmenwechsel oder eine Unternehmenstransformation unterstützen. Die Erkenntnisse des Projekts sollen Vergabeinstitutionen von Umwelt- und Nachhaltigkeitswettbewerben eine Orientierung geben in den Fragen: • Was macht hochwertige Wettbewerbe aus? • Wie können kleine und mittelständische Unternehmen (KMUs) davon profitieren und Awards nutzen? • Können Awards zu einer gesamtgesellschaftlichen nachhaltigen Transformation beitragen? Für das Forschungsprojekt SIEGER wurden mittels Methoden-Mix deutschlandweit Vergabeinstitutionen von Awards und Unternehmen befragt. Gesammelt, systematisiert und abgeleitet werden Möglichkeiten resilienter, erfolgsversprechender Ansätze einer nachhaltigen Transformation der Vergabekonzepte; Möglichkeiten zur Stärkung von KMUs aus Sicht von Vergabeinstitutionen (Awardgebende), von Unternehmen (Awardnehmende) und von weiteren Experten sowie strategische Empfehlungen für zukunftsfähige Umwelt- und Nachhaltigkeitswettbewerbe. Die Projektbearbeitung übernahm der AK BEST (Business Excellence and Sustainability Transformation), eine Initiative angegliedert an die Universität Hohenheim, mit Schwerpunkt in der Award-Forschung. Zentrale Aussagen der Studie lauten: 1. Auf den Ausbau oder eine Weiterentwicklung der Nachhaltigkeitstransformation können hochwertige Nachhaltigkeitsawards eine positive Auswirkung haben – auch wenn die (Unternehmens-)Welt von Krisen und/oder Unsicherheiten beeinflusst ist. 2. Die Stärken und Chancen von Awards werden höher bewertet als die Schwächen und Risiken. 3. Insbesondere der Imagegewinn, Sympathiegewinn bei Kund*innen und die Motivation bei Mitarbeiter*innen werden von Unternehmen als positive Effekte genannt. 4. Für kleine und mittelständische Unternehmen (KMUs) sind vor allem Finanzier-barkeit und Zeitaufwand eine Hürde für die Teilnahme, für Großunternehmen ist es die Vielzahl an Awards und deren Glaubwürdigkeit. 5. (Nachhaltigkeits-)Awards spielen auch in der Zukunft eine Rolle für Unternehmen, wenn die Vergabeinstitutionen fünf wesentliche Merkmale sicherstellen: Qualität, Glaubwürdigkeit, Transparenz, Zugänglichkeit und Wirkung. 6. Für zukünftige oder Zukunftsawards erwarten Unternehmen Kommunikations-fähigkeit (für sich) und Kommunikation (der Vergabeinstitution), um externe sowie interne Stakeholder in das Handeln und ggfs. eine Transformation zu integrieren. 7. Zentral ist dafür, dass auch die Vergabeinstitutionen in der Lage sind, ihre Awards situativ anzupassen und ggfs. eine Selbstveränderung zu schaffen (Resilienz). In diesem Abschlussbericht des Forschungsprojekts SIEGER werden diese Ergebnisse detailliert beschrieben, Ziel und Methodik der Forschungsstudie benannt und ein Weg in die Zukunft für (Nachhaltigkeits-)Awards aufgezeigt.
Untersuchungen zur Vererbung von Qualitätseigenschaften bei Silomais (Zea mays L.)
(2004) Krützfeldt, Birte A. E.; Geiger, Hartwig H.
In central Europe silage maize (Zea mays L.) is a major source of cattle feed. The quality or the feeding value of a silage maize variety mainly depends on its digestibility and energy content. The establishing of the near-infrared-reflectance-spectroscopy- (NIRS) technique allows the analysis of more than one quality determining trait simultaneously in an easy and short way. In this study one objective was the influence of stover quality on whole plant quality. In hybrid breeding indirect selection on the basis of inbred line performance has a great advantage because the number of testcrosses can be reduced. Therefore it was tested, if the stover quality of the testcrosses could be predicted on the line per se value. Besides the correlation between agronomic and quality traits was analysed. In the years 1999 and 2000 the evaluation of the stover of the lines and testcrosses and the whole plant of the testcrosses was conducted at four climatically diverse sites in Germany. Three data sets with flint-lines and dent-lines, each proved with one tester-line, were evaluated for the correlation between inbred line and testcross performance. The test for combining ability was performed with three smaller data sets also consisting of flint-lines and dent-lines with two tester-lines per data set. The coefficients of heritability were high for the agronomic and quality traits in the data sets of the inbred lines. In the data sets of the testcrosses the variation attributed to the genotypic variance was smaller, genotype × location-interactions were of lower importance. In the data sets, each with two tester-lines it was obvious that for quality traits of stover and whole plant the interaction between line and tester was mostly not significant. The genotypic correlation between inbred line and testcross performance was highly significant for almost all quality traits of the stover, but the correlation coefficients were mostly only moderate. Only the expected success of an indirect selection on line per se- value for cell-wall digestibility of the stover exceeded that of the direct selection on testcross performance in all data sets. However, a selection of extremes on line per se value should be possible for stover digestibility. The genotypic correlations between comparable traits in stover and whole plant were mainly low. The cell-wall digestibility was the only trait which was independent of dry matter content. For evaluation of the further quality traits attention has to be paid to the maturity stage, to prevent a maturity-based bias of the results. In the testcrosses stover digestibility increased and whole plant digestibility was reduced with an increase in whole plant dry matter yield. But the genotypic correlations were only moderate and a simultaneous selection to improve quality and yield seems to be possible.
Zur Bedeutung geschützter Herkunftsangaben
(2005) Becker, Tilman
Das europäische Schutzsystem für geographische Herkunftsangaben bietet die Möglichkeit für den Aufbau regionaler Wertschöpfungsketten. Diese Wertschöpfungsketten sind geeignet, den Verbraucherwünschen nach regionaler Herkunft entgegenzukommen, den Interessen der regionalen Landwirtschaft zu dienen und Arbeitsplätze in der Region zu schaffen. Im Rahmen der WTO-Verhandlungen hat die kontroverse Diskussion über den internationalen Schutz der geographischen Herkunftsangabe eine erhebliche Bedeutung erlangt. Der Beitrag behandelt das ganze Spektrum geographischer Herkunftsangabe - von der geschützten Ursprungsbezeichnung und der geschützten geographischen Angabe über die kombinierte Herkunftsangabe, die Gattungsbezeichnung, die individualisierte geographischen Angabe bis hin zur einfachen Herkunftsangabe. Er geht auf die rechtliche Abgrenzung und die unterschiedliche marken- und beihilferechtlichen Bedeutungen dieser verschiedenen Formen der Herkunftsangabe ein. Die Bedeutung der Herkunftsangabe als Qualitätssignal und als Standard wird diskutiert. Die Entwicklung der Bedeutung und Nutzung des europäischen Schutzsystems für die geographischen Herkunftsangaben in Deutschland und anderen Ländern der Europäischen Union wird untersucht. Abschließend wird auf die internationalen rechtlichen Rahmenbedingungen für den Schutz geographischer Herkunftsangaben eingegangen. Der Beitrag zeigt, dass in Deutschland ein erheblicher Nachholbedarf bei der Nutzung des europäischen Schutzsystems besteht.
Der Zusammenhang zwischen Preis und Qualität auf Konsumgütermärkten : Befunde, Interpretationen, Schlussfolgerungen
(2015) Imkamp, Heiner; Sousa-Poza, Alfonso
For more than 60 years, numerous studies have shown low price-quality correlations on consumer goods markets. The coefficients are mostly close to 0.2. That prices fail to function as valid indicators of product quality has often been interpreted as informational market failure. This dissertation, however, argues, that, according to the economic theory of price formation, prices are not an indicator of quality, but an indicator of scarcity. This allows the conclusion that workable consumer goods markets, at least as seen from the consumers point of view, should be characterized by low or even negative correlation coefficients rather than by strong positive coefficients.