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Wädenswil, Switzerland

Fantke P.,University of Stuttgart | Charles R.,Agroscope Changins Wadenswil ACW | Alencastro L.F.D.,Ecole Polytechnique Federale de Lausanne | Friedrich R.,University of Stuttgart | And 2 more authors.
Chemosphere | Year: 2011

Human intake of pesticide residues from consumption of processed food plays an important role for evaluating current agricultural practice. We take advantage of latest developments in crop-specific plant uptake modeling and propose an innovative dynamic model to estimate pesticide residues in the wheat-environment system, dynamiCROP. We used this model to analyze uptake and translocation of pesticides in wheat after foliar spray application and subsequent intake fractions by humans. Based on the evolution of residues in edible parts of harvested wheat we predict that between 22. mg and 2.1. g per kg applied pesticide are taken in by humans via consumption of processed wheat products. Model results were compared with experimentally derived concentrations in wheat ears and with estimated intake via inhalation and ingestion caused by indirect emissions, i.e. the amount lost to the environment during pesticide application. Modeled and measured concentrations in wheat fitted very well and deviate from less than a factor 1.5 for chlorothalonil to a maximum factor 3 for tebuconazole. Main aspects influencing pesticide fate behavior are degradation half-life in plant and time between pesticide application and crop harvest, leading to variations in harvest fraction of at least three orders of magnitude. Food processing may further reduce residues by approximately 63%. Intake fractions from residues in sprayed wheat were up to four orders of magnitude higher than intake fractions estimated from indirect emissions, thereby demonstrating the importance of exposure from consumption of food crops after direct pesticide treatment. © 2011 Elsevier Ltd.

Rezzonico F.,Agroscope Changins Wadenswil ACW | Vogel G.,Mabritec AG | Duffy B.,Agroscope Changins Wadenswil ACW | Tonolla M.,Microbiology Unit
Applied and Environmental Microbiology | Year: 2010

Pantoea agglomerons is an ecologically diverse taxon that includes commercially important plant-beneficial strains and opportunistic clinical isolates. Standard biochemical identification methods in diagnostic laboratories were repeatedly shown to run into false-positive identifications of P. agglomerons, a fact which is also reflected by the high number of 16S rRNA gene sequences in public databases that are incorrectly assigned to this species. More reliable methods for rapid identification are required to ascertain the prevalence of this species in clinical samples and to evaluate the biosafety of beneficial isolates. Whole-cell matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) methods and reference spectra (SuperSpectrum) were developed for accurate identification of P. agglomerons and related bacteria and used to detect differences in the protein profile within variants of the same strain, including a ribosomal point mutation conferring streptomycin resistance. MALDI-TOF MS-based clustering was shown to generally agree with classification based on gyrB sequencing, allowing rapid and reliable identification at the species level. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

Hofstetter V.,Agroscope Changins Wadenswil ACW | Buyck B.,CNRS Systematics, Biodiversity and Evolution Institute | Croll D.,ETH Zurich | Viret O.,Agroscope Changins Wadenswil ACW | And 2 more authors.
Fungal Diversity | Year: 2012

Esca disease, which attacks the wood of grapevine, has become increasingly devastating during the past three decades and represents today a major concern in all wine-producing countries. This disease is attributed to a group of systematically diverse fungi that are considered to be latent pathogens, however, this has not been conclusively established. This study presents the first in-depth comparison between the mycota of healthy and diseased plants taken from the same vineyard to determine which fungi become invasive when foliar symptoms of esca appear. An unprecedented high fungal diversity, 158 species, is here reported exclusively from grapevine wood in a single Swiss vineyard plot. An identical mycota inhabits wood of healthy and diseased adult plants and presumed esca pathogens were widespread and occurred in similar frequencies in both plant types. Pioneer esca-associated fungi are not transmitted from adult to nursery plants through the grafting process. Consequently the presumed esca-associated fungal pathogens are most likely saprobes decaying already senescent or dead wood resulting from intensive pruning, frost or other mecanical injuries as grafting. The cause of esca disease therefore remains elusive and requires well executive scientific study. These results question the assumed pathogenicity of fungi in other diseases of plants or animals where identical mycota are retrieved from both diseased and healthy individuals. © 2012 The Author(s).

Smits T.H.M.,Agroscope Changins Wadenswil ACW | Duffy B.,Agroscope Changins Wadenswil ACW
Archives of Microbiology | Year: 2011

Genomics has clarified the biosynthetic pathway for desferrioxamine E critical for iron acquisition in the enterobacterial fire blight pathogen Erwinia amylovora. Evidence for each of the individual steps and the role of desferrioxamine E biosynthesis in pathogen virulence and cell protection from host defenses is presented. Using comparative genomics, it can be concluded that desferrioxamine biosynthesis is ancestral within the genera Erwinia and Pantoea. © Springer-Verlag 2011.

Smits T.H.M.,Agroscope Changins Wadenswil ACW | Rezzonico F.,Agroscope Changins Wadenswil ACW | Kamber T.,Agroscope Changins Wadenswil ACW | Goesmann A.,Bielefeld University | And 4 more authors.
Journal of Bacteriology | Year: 2010

Pantoea vagans is a Gram-negative enterobacterial plant epiphyte of a broad range of plants. Here we report the 4.89-Mb genome sequence of P. vagans strain C9-1 (formerly Pantoea agglomerans), which is commercially registered for biological control of fire blight, a disease of pear and apple trees caused by Erwinia amylovora. Copyright © 2010, American Society for Microbiology. All Rights Reserved.

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