State Viticulture Institute Freiburg

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Sack M.,Karlsruhe Institute of Technology | Sigler J.,Karlsruhe Institute of Technology | Eing C.,Karlsruhe Institute of Technology | Stukenbrock L.,State Viticulture Institute Freiburg | And 3 more authors.
IEEE Transactions on Plasma Science | Year: 2010

In the course of the production of red wine, electroporation of mash enables a fast extraction of the red pigments from the skin without remarkable heating of the mash. For white wine, the formation of pores in the cells fosters, among others, the extraction of flavoring substances. During the harvest in 2008, the electroporation device KEA-WEIN has been operated successfully in two wineries. All together, more than 5 m 3 of mash has been treated. During this year's experiments, some experience in the operation of the electroporation device on-site in a winery has been gained. To facilitate the evaluation of the experimental results, the electroporation device has been equipped with different sensors and measurement systems, e.g., for the power drawn from the grid and the temperature of the mash before and after the electroporation. The data logged during one exemplary run are presented in this paper. Based on the measurements, an estimation about the energy consumption and efficiency of the device has been made. Must and wine made from the grape varieties Pinot Noir and Riesling have been chemically analyzed. Selected data are presented in this paper. © 2010 IEEE.


Sack M.,Karlsruhe Institute of Technology | Sigler J.,State Viticulture Institute Freiburg | Frenzel S.,SUDZUCKER AG Mannheim Ochsenfurt | Eing C.,Karlsruhe Institute of Technology | And 6 more authors.
Food Engineering Reviews | Year: 2010

Electroporation is an innovative method in food processing to support the extraction of substances from cells. By applying a pulsed electric field to the tissue, the cell membranes are charged and pores are formed in the membranes fostering the extraction. Although this principle is common to all electroporation devices, due to the different properties of each material, the devices and processes have to be designed for each application individually. The publication gives an overview on the advantages of electroporation for the processing of crushed grapes, sugar beets, and energy crop, and also on the design of electroporation devices for these applications. © 2010 Springer Science + Business Media, LLC.


Fischer M.,Julius Kuhn Institute | Kassemeyer H.-H.,State Viticulture Institute Freiburg
Vitis - Journal of Grapevine Research | Year: 2012

Impact of abiotic factors has been recently discussed in grapevine trunk diseases such as Esca. Emphasis of the present study lies on the relation between different water regime ("normal" and "stress") on one side and growth characters as well as Esca-related wood symptoms on the other side. Trials were conducted in the greenhouse with cuttings of the cultivars 'Müller-Thurgau' and 'Riesling', part of which artificially infected with Phaeomoniella chlamydospora. During a 12 month incubation period the following characters were evaluated: shoot length, weight of stem, expression of wood symptoms, and survival rate of plants. For evaluation of wood symptoms a numerical system was developed that is applied here for the first time. The obtained results indicate that water supply plays a statistically significant role, with plants under "stress" regime shown to be more affected. No strict spatial correlation was found to exist between wood symptoms and physical presence of the pathogen.


Sprenger M.,Albert Ludwigs University of Freiburg | Erhardt M.,State Viticulture Institute Freiburg | Riedel M.,State Viticulture Institute Freiburg | Weiler M.,Albert Ludwigs University of Freiburg
Agriculture, Ecosystems and Environment | Year: 2016

The European Water Framework Directive (EWFD) aims to achieve a good chemical status for the groundwater bodies in Europe by the year 2015. Despite the effort to reduce the nitrate pollution from agriculture within the last two decades, there are still many groundwater aquifers that exceed nitrate concentrations above the EWFD threshold of 50 mg L-1. Viticulture is seen as a major contributor of nitrate leaching and sowing of a green cover was shown to have a positive effect on lowering the nitrate loads in the upper 90 cm of the soil. However, the consequences for nitrate leaching into the subsoil were not yet tested. We analyzed the nitrate concentrations and pore water stable isotope composition (δ 2H) to a depth of 380 cm in soil profiles under an old vineyard and a young vineyard with either soil tillage or permanent green cover in between the grapevines. The pore water δ 2H data was used to calibrate a soil physical model, which was then used to infer the age of the soil water at different depths. This way, we could relate elevated nitrate concentrations below an old vineyard to tillage processes that took place during the winter two years before the sampling. We further showed that the elevated nitrate concentration in the subsoil of a young vineyard can be related to the soil tillage prior to the planting of the new vineyard. If the soil was kept bare due to tillage, a nitrate concentration of 200 kg NO3 --N ha-1 was found in 290-380 cm depth 2.5 years after the set-up of the vineyard. The amount of nitrate leaching was considerably reduced due to a seeded green cover between the grapevines that took up a high share of the mineralized nitrate reducing a potential contamination of the groundwater. © 2016 Elsevier B.V..


Trondle D.,Karlsruhe Institute of Technology | Schroder S.,Karlsruhe Institute of Technology | Kassemeyer H.-H.,State Viticulture Institute Freiburg | Kiefer C.,Heidelberg Institute of Plant science | And 2 more authors.
American Journal of Botany | Year: 2010

Premise of the study: This work represents the first molecular phylogeny of the economically important genus Vitis, an important genetic resource for breeding in grapevine, Vitis vinifera. Methods: A molecular phylogeny of Vitis using a combined data set of three noncoding regions of the plastid DNA genome was constructed from 47 accessions covering 30 species of Vitis. The data for the trnL-F marker were combined with previously published data across the Vitaceae. Key results: The molecular phylogeny demonstrated monophyly of the genus Vitis. Based on the combined analysis of three genes, Vitis is split into three clades that mirror the continental distribution of these accessions. The diversity is highest in the Asian clade, but the general genetic distances across taxa from different continents are relatively small. Conclusions: The findings support a relatively recent and intense gene flow between East Asia and North America and the possible impact of hybridization on the evolution of the genus Vitis. Taxon identity in important stock collections should be screened carefully because roughly 10% of the accessions analyzed in the present study had been misidentified. © 2010 Botanical Society of America.


Harm A.,Hohere Bundeslehranstalt und Bundesamt fur Wein und Obstbau | Kassemeyer H.-H.,State Viticulture Institute Freiburg | Seibicke T.,State Viticulture Institute Freiburg | Regner F.,Hohere Bundeslehranstalt und Bundesamt fur Wein und Obstbau
American Journal of Enology and Viticulture | Year: 2011

Chemical and natural resistance-inducing substances may be used to decrease the susceptibility of plants to various pathogens, thus reducing the application of pesticides in agriculture. This study evaluated the potential of biocontrol products and of plant extracts. The invoked mode of induced resistance was verified to control downy mildew on grapevine plants using leaf discs and potted vines. Induced resistance was determined by the increase of pathogenesis-related (PR) proteins, including peroxidase, polyphenol oxidase, β-1,3-glucanase, phenylalanine ammonia-lyase, stilbene synthase, β-1,3-glucanase, PR-1 protein, and caffeoyl-coenzyme A 3-O-methyltransferase. Candidate resistance inducers, including Solidago canadensis (CanG) extract, mycelium extract of Penicillium crysogenum (PEN), linoleic acid (LIN), and biocontrol agent Aureobasidium pullulans (Aureo), and chemical elicitors 3-dl-β-aminobutyric acid (BABA) and benzothiadiazole (BTH) were tested against Plasmopara viticola in potted vines grown outdoors. BABA, BTH, and CanG provided a protection of more than 80%, whereas PEN, LIN, and Aureo provided minimal protection. BABA and Aureo were not able to inhibit zoospores, whereas a concentration-dependent inhibition of zoospore mobility was observed for all other tested substances. BTH, CanG, PEN, and LIN induced the production of a broad spectrum of resistance-related metabolites, whereas Aureo did not cause any response. BABA provoked formation of necrotic spots and PR proteins immediately after inoculation. These results indicate the potential to partly induce natural resistance metabolites to enhance tolerance of grapevine plants to P. viticola, thus offering a synergistic effect when used with fungicides and aiding in reducing their ecological burden, even if they are not effective enough to replace them fully. © 2011 by the American Society for Enology and Viticulture. All rights reserved.


Panassiti B.,State Viticulture Institute Freiburg | Breuer M.,State Viticulture Institute Freiburg | Marquardt S.,State Viticulture Institute Freiburg | Biedermann R.,Institute for Environmental Modelling
Bulletin of Entomological Research | Year: 2013

Species distribution models (SDMs), which are well established in many fields of biological research, are still uncommon in the agricultural risk analysis of pest insects. To exemplify the use of SDMs, we investigated the influence of environmental factors on the occurrence of Hyalesthes obsoletus Signoret (Hemiptera: Cixiidae). The planthopper is the only known vector of the grapevine yellows disease 'bois noir'. The study was conducted in 145 locations in the Baden region of southwest Germany. The planthopper was surveyed on host plant patches, consisting of stinging nettle and/or bindweeds. We used a stratified modelling framework where (1) species presence-absence data were related to an extensive environmental dataset using logistic regressions; and (2) different types of average models were developed based on an information theoretic method. The results show that the incidence of H. obsoletus is associated to above- as well as below-ground environmental factors, particularly to the amount of fine soil and average annual precipitation. This result was consistent across all average models. The relative importance of other environmental variables was dependent upon the average model under consideration and thus may vary according to their intended use, either the explanation of habitat requirements or the prediction and mapping of occurrence risks. The study showed that SDMs offer a quantification of species' habitat requirements and thus, could represent a valuable tool for pest management purposes. By providing examples of current issues of grapevine pests in viticulture, we discuss the use of SDMs in agricultural risk analysis and highlight their advantages and caveats. Copyright © Cambridge University Press 2013.


Delmotte F.,CNRS Agroecology Lab | Delmotte F.,University of Bordeaux 1 | Mestre P.,CNRS Vine Health and Wine Quality | Schneider C.,CNRS Vine Health and Wine Quality | And 8 more authors.
Infection, Genetics and Evolution | Year: 2014

Crop pathogens evolve rapidly to adapt to their hosts. The use of crops with quantitative disease resistance is expected to alter selection of pathogen life-history traits. This may result in differential adaptation of the pathogen to host cultivars and, sometimes, to the erosion of quantitative resistance. Here, we assessed the level of host adaptation in an oomycete plant pathogenic species. We analysed the phenotypic and genetic variability of 17 Plasmopara viticola isolates collected on Vitis vinifera and 35 isolates from partially resistant varieties (Regent and genotypes carrying the Rpv1 gene). Cross-inoculation experiments assessed two components of aggressiveness and a life-history trait of the pathogen: disease severity, sporangial production and sporangia size. The results contribute evidence to the emergence of P. viticola aggressive isolates presenting a high level of sporulation on the partially resistant Regent. By contrast, no adaptation to the Rpv1 gene was found in this study. The erosion of Regent resistance may have occurred in less than 5. years and at least three times independently in three distant wine-producing areas. Populations from resistant varieties showed a significant increase in sporangia production capacity, indicating an absence of fitness costs for this adaptation. The increase in the number of sporangia was correlated with a reduction in sporangia size, a result which illustrates how partial plant disease resistance can impact selection of the pathogen's life-history traits. This case study on grapevine downy mildew shows how new plant pathogen populations emerge in agro-ecosystems by adapting to partial host resistance. This adaptive pattern highlights the need for wise management of plant partial disease resistance to ensure its sustainability over time. © 2013 Elsevier B.V.


Boso S.,Mision Biologica de Galicia | Alonso-Villaverde V.,Mision Biologica de Galicia | Martinez M.-C.,Mision Biologica de Galicia | Kassemeyer H.-H.,State Viticulture Institute Freiburg
American Journal of Enology and Viticulture | Year: 2012

Stilbenic phytoalexins have been associated with disease resistance. In Vitis spp., stilbene synthesis can be induced by UV irradiation, treatment with a variety of substance extracts, and inoculation with Botrytis cinerea or Plasmopara viticola. The aim of the present work was to examine the relationship between stilbene production and the level of resistance of different Vitis genotypes to P. viticola. The ability of different grapevine genotypes (Vitis vinifera L. cvs. Tempranillo, Touriga Nacional, Pinot noir, and Cabernet Sauvignon and Vitis riparia cv. Gloire de Montpellier) to resist Plasmopara viticola infection was assessed via their potential to accumulate toxic stilbenic phytoalexins. Leaf discs taken from plants belonging to these genotypes were inoculated with P. viticola sporangia and disease severity was determined five days later. Stilbene production was quantified in similar leaf material at 6, 24, 48, and 72 hr postinoculation. After P. viticola infection, the resistant genotype V. riparia showed high production of the phytotoxic stilbenes ε- and δ-viniferin, which limited the development of the pathogen and prevented it from producing spores. Indeed, this genotype was associated with the lowest sporulation values. No relationship was observed, however, between resistance and these compounds in the V. vinifera genotypes. Further study is required to define the role of stilbenic phytoalexins in resistance to P. viticola. © 2012 by the American Society for Enology and Viticulture. All rights reserved.


PubMed | CNRS Agroecology Lab, CNRS Vine Health and Wine Quality, State Viticulture Institute Freiburg and University of Pécs
Type: | Journal: Infection, genetics and evolution : journal of molecular epidemiology and evolutionary genetics in infectious diseases | Year: 2014

Crop pathogens evolve rapidly to adapt to their hosts. The use of crops with quantitative disease resistance is expected to alter selection of pathogen life-history traits. This may result in differential adaptation of the pathogen to host cultivars and, sometimes, to the erosion of quantitative resistance. Here, we assessed the level of host adaptation in an oomycete plant pathogenic species. We analysed the phenotypic and genetic variability of 17 Plasmopara viticola isolates collected on Vitis vinifera and 35 isolates from partially resistant varieties (Regent and genotypes carrying the Rpv1 gene). Cross-inoculation experiments assessed two components of aggressiveness and a life-history trait of the pathogen: disease severity, sporangial production and sporangia size. The results contribute evidence to the emergence of P. viticola aggressive isolates presenting a high level of sporulation on the partially resistant Regent. By contrast, no adaptation to the Rpv1 gene was found in this study. The erosion of Regent resistance may have occurred in less than 5years and at least three times independently in three distant wine-producing areas. Populations from resistant varieties showed a significant increase in sporangia production capacity, indicating an absence of fitness costs for this adaptation. The increase in the number of sporangia was correlated with a reduction in sporangia size, a result which illustrates how partial plant disease resistance can impact selection of the pathogens life-history traits. This case study on grapevine downy mildew shows how new plant pathogen populations emerge in agro-ecosystems by adapting to partial host resistance. This adaptive pattern highlights the need for wise management of plant partial disease resistance to ensure its sustainability over time.

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