Person: Flade, Jens
Lade...
E-Mail-Adresse
Geburtsdatum
Forschungsvorhaben
Organisationseinheiten
Berufsbeschreibung
Nachname
Flade
Vorname
Jens
Name
3 Ergebnisse
Suchergebnisse
Gerade angezeigt 1 - 3 von 3
Veröffentlichung Pyrrolizidinalkaloide in Senecio vulgaris L. in Abhängigkeit vom Entwicklungsstadium unter Betrachtung verschiedener Jahreszeiten(2020) Beschow, Heidrun; Flade, Jens; Plescher, AndreasDas Gewöhnliche Greiskraut (Senecio vulgaris L.) wird aufgrund seiner toxischen Inhaltsstoffe (Pyrrolizidinalkaloide, PAs) und seines enormen Verbreitungspotentials in landwirtschaftlichen Sonderkulturen als problematisch eingestuft (ROBINSON et al., 2003; BFR, 2007; WIEDENFELD, 2011; WIEDENFELD und EDGAR, 2011). Die vorliegende Untersuchung hatte daher zum Ziel in Parzellenfreilandversuchen die Wachstumsparameter von Senecio vulgaris und den Gehalt von verschiedenen PAs hinsichtlich ontogenetischer Unterschiede zu verschiedenen Jahreszeiten zu untersuchen. Wie bereits für andere Senecio-Arten gezeigt, wird auch in Senecio vulgaris der PA-Gehalt (PA-Gesamtsumme, tertiäre PAs und PA-N-oxide) je nach Jahreszeit durch das Entwicklungsstadium beeinflusst. Allgemein zeigt sich eine Tendenz, dass die PA-Konzentration bis zur Vollblüte ansteigt und nachfolgend zur Frucht- und Samenreife wieder abnimmt. Von den N-oxiden wurden jeweils höhere Gehalte als von den entsprechenden tertiären PAs gefunden. Die Einzelverbindungen werden in ihrer Konzentration unterschiedlich beeinflusst; während einige PAs zu jeder Jahreszeit ontogenetisch verändert wurden (Retrorsin-N-oxid, Senecionin), konnte dieses für Senecivernin-N-oxid nicht nachgewiesen werden. © Der Autor/Die Autorin 2020Veröffentlichung Occurrence of nine pyrrolizidine alkaloids in Senecio vulgaris L. depending on developmental stage and season(2019) Beschow, Heidrun; Flade, Jens; Wensch-Dorendorf, MonikaThe contamination of phytopharmaceuticals and herbal teas with toxic plants is an increasing problem. Senecio vulgaris L. is a particularly noxious weed in agricultural and horticultural crops due to its content of toxic pyrrolizidine alkaloids (PAs). Since some of these compounds are carcinogenic, the distribution of this plant should be monitored. The amount of PAs in S. vulgaris is affected by various factors. Therefore, we investigated the occurrence of PAs depending on the developmental stage and season. A systematic study using field-plot experiments (four seasons, five developmental stages of the plants: S1 to S5) was performed and the PA concentration was determined via LC-MS/MS analysis. The total amount of PAs in the plant increased with the plant development, however, the total PA concentrations in the dry matter remained nearly unchanged, whilst trends for specific PAs were observed. The concentrations of PA-N-oxides (PANOs) were much higher than that of tertiary PAs. Maximal amounts of the PA total were 54.16 +/- 4.38 mg/plant (spring, S5). The total amount of PAs increased strongly until later developmental stages. Therefore, even small numbers of S. vulgaris may become sufficient for relevant contaminations set out by the maximal permitted daily intake levels recommended by the European Food Safety Authority (EFSA). Quelle: https://www.mdpi.comVeröffentlichung Risk mitigation measures for pesticide runoff: How effective are they?(2023) Klein, Michael; Flade, Jens; Klein, Judith; Großmann, Dietlinde; Türkowsky, DominiqueBACKGROUND One of the most important sources of pesticide pollution of surface waters is runoff and erosion from agricultural fields after rainfall. This study analyses the efficacy of different risk mitigation measures to reduce pesticide runoff and erosion inputs into surface waters from arable land excluding rice fields. RESULTS Three groups of risk mitigation measures were quantitatively analyzed: vegetative filter strips, micro-dams in row crops and soil conservation measures. Their effectiveness was evaluated based on a meta-analysis of available experimental data using statistical methods such as classification and regression trees, and exploratory data analysis. Results confirmed the effectiveness of vegetative filter strips and micro-dams. Contrary to common assumption, the width of vegetative filter strips alone is not sufficient to predict their effectiveness. The effectiveness of soil conservation measures (especially mulch-tillage) varied widely. This was in part due to the heterogeneity of the available experimental data, probably resulting from the inconsistent implementation and the inadequate definitions of these measures. CONCLUSION Both vegetative filter strips and micro-dams are effective and suitable, and can therefore be recommended for quantitative assessment of environmental pesticide exposure in surface waters. However, the processes of infiltration and sedimentation in vegetative filter strips should be simulated with a mechanistic model like Vegetative Filter Strip Modeling System, VFSMOD. The reduction effect of micro-dams can be modelled by reducing the runoff curve number, e.g., in the pesticide root zone model, PRZM. Soil conservation measures are in principle promising, but further well-documented data are needed to determine under which conditions they are effective. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.