Ralf Tilcher

Assessing the effects of three potential chemical repellents to prevent bird damage to corn seeds and seedlings

BACKGROUNDnBird damage to seeds and seedlings of maize (Zea mays) and other crops is widespread, especially in organic farming, because no adequate seed protection is available. In this study, the effect of seed treatments with three substances likely to affect bird feeding behaviour (anthraquinone, pulegone and methyl anthranilate) was tested. Their repellent effect was tested in food and seedling choice (treated versus untreated) experiments with feral pigeons (Columba livia f. domestica) in aviaries. Most efficient variants were additionally tested in the field, where wild birds had unlimited access.nnnRESULTSnIn aviaries, untreated seeds were clearly preferred over treated seeds by pigeons. The highest feeding deterrence effect occurred with the treatment variants pulegone 1.4 mL kg(-1) and methyl anthranilate 0.085 mL kg(-1). In contrast, there was no repellent effect if seedlings were offered to the pigeons in aviaries. The same applies to the number of maize seeds and seedlings grown from treated and untreated seeds, which were damaged in the field mainly by pheasants (Phasianus colchicus).nnnCONCLUSIONnThe study shows that the chemicals failed to repel feeding by birds in Germany. Further studies should concentrate on alternative, systemic effective substances possibly based on plant secondary metabolites to yield a bird repellent usable in organic farming.

Entwicklung von Verkapselungsmethoden für Pflanzenextrakte alsSaatgutbehandlung gegen Vogelfraß in der Landwirtschaft

Recent studies on endophytic Kosakonia radicincitans DSM 16656T demonstrated a wide plant growth-promoting activity. The application of this Gram-negative bacterium as a biofertilizer is limited due to the lack of adequate formulation that protects the cells during drying and storage and supports plant colonization. Here we set out to elucidate the compatible solutes accumulation influence of K. radicincitans triggered by osmotic stress on its capacity as an endophyte in radish plants. We found that physiological modifications by osmotic stress treatments and accumulation of compatible solutes during cultivation, improve the capability of K. radicincitans formulated in dry beads to colonize and to promote radish growth. Thus, pre-conditioning of cells with NaCl 4% and by adding compatible solutes such as hydroxyectoine during cultivation induced a positive effect on relative gene expression response, enhancing significantly the ability to colonize plant tissue up to 10 fold. Additionally, when this osmolyte was added, either dry matter of tuber or leaves increased by 3 % and 13.59 %, respectively in comparison to beads without the bacterium. These first results indicate that a systematic approach to cultivation and formulation may increase the endophytic capacity of this bacterium.

Mikroverkapselung von Pflanzenextrakten zur Einarbeitung insprühfähige Formulierungen

Recent studies on endophytic Kosakonia radicincitans DSM 16656T demonstrated a wide plant growth-promoting activity. The application of this Gram-negative bacterium as a biofertilizer is limited due to the lack of adequate formulation that protects the cells during drying and storage and supports plant colonization. Here we set out to elucidate the compatible solutes accumulation influence of K. radicincitans triggered by osmotic stress on its capacity as an endophyte in radish plants. We found that physiological modifications by osmotic stress treatments and accumulation of compatible solutes during cultivation, improve the capability of K. radicincitans formulated in dry beads to colonize and to promote radish growth. Thus, pre-conditioning of cells with NaCl 4% and by adding compatible solutes such as hydroxyectoine during cultivation induced a positive effect on relative gene expression response, enhancing significantly the ability to colonize plant tissue up to 10 fold. Additionally, when this osmolyte was added, either dry matter of tuber or leaves increased by 3 % and 13.59 %, respectively in comparison to beads without the bacterium. These first results indicate that a systematic approach to cultivation and formulation may increase the endophytic capacity of this bacterium.

Entwicklung eines pflanzlichen Vogelrepellent – Projekt DevelOPAR

Recent studies on endophytic Kosakonia radicincitans DSM 16656T demonstrated a wide plant growth-promoting activity. The application of this Gram-negative bacterium as a biofertilizer is limited due to the lack of adequate formulation that protects the cells during drying and storage and supports plant colonization. Here we set out to elucidate the compatible solutes accumulation influence of K. radicincitans triggered by osmotic stress on its capacity as an endophyte in radish plants. We found that physiological modifications by osmotic stress treatments and accumulation of compatible solutes during cultivation, improve the capability of K. radicincitans formulated in dry beads to colonize and to promote radish growth. Thus, pre-conditioning of cells with NaCl 4% and by adding compatible solutes such as hydroxyectoine during cultivation induced a positive effect on relative gene expression response, enhancing significantly the ability to colonize plant tissue up to 10 fold. Additionally, when this osmolyte was added, either dry matter of tuber or leaves increased by 3 % and 13.59 %, respectively in comparison to beads without the bacterium. These first results indicate that a systematic approach to cultivation and formulation may increase the endophytic capacity of this bacterium.

Entwicklung von Verkapselungsmethoden für Pflanzenextrakte im Projekt DevelOPAR

In fur Honigbienen attraktiven Anbaukulturen wie Raps und Obst ist es vielfach ublich, und auch zulassig, wahrend der Blute mehrere Pflanzenschutzmittel aus verschiedenen Wirkstoffklassenals Tankmischung auszubringen (z.B. Fungizide, Herbizide, Wachstumsregler, Insektizide oder Mikronahrstoffe). In der Regel werden die Bienen dabei nicht gefahrdet, wenn alle Vorschriften eingehalten werden, die fur die beteiligten Mischungskomponenten gelten. Fur manche Wirkstoffgruppen sind jedoch auch synergistische Wirkungssteigerungen bekannt, wie fur die bereits hinreichend untersuchte nsynergistische Wirkung von Insektiziden aus der Wirkstoffgruppe der Pyrethroide in Kombination mit bestimmten Fungiziden aus der Klasse der Ergosterol-Biosynthese-Hemmer. Hier kann bei einer gemeinsamen Ausbringung in einer Tankmischung eine Verscharfung der Anwendungsbestimmungen und Auflagen erfolgen, aus zwei bienenungefahrlichen Produkten (B4) wird somit eine bienengefahrliche Mischung (B1/B2). Da in der landwirtschaftlichen Praxis jedoch immer wieder neue Wirkstoffe entwickelt werden und Mischungskombinationen hinzukommen, arbeitet das Julius Kuhn-Institut praventiv an der Erstellung eines einfachen Screening-Verfahren auf Laborebene zur schnellen Detektion potentiell risikobehafteter Wirkstoff- und Mittelkombinationen. In einem ersten Schritt wurden hierfur Pflanzenschutzmittelmischungen in Laborversuchen (Spritzkammer) getestet, welche haufig im Raps- bzw. Obstanbau eingesetzt werden. nIn einem zweiten Schritt werden dann potentiell kritische oder haufig eingesetzte Wirkstoffkombinationen in Halbfreiland- bzw. Freilandversuchen gepruft. Dabei wird untersucht, ob und inwiefern ein erhohtes Risiko fur Bienen besteht und ob, und wenn ja welche zusatzliche Auflagen erforderlich sind. nFur die Versuche in der Spritzkammer werden junge Honigbienen einen Tag vor der Applikation aus dem Honigraum gesunder Wirtschaftsvolker entnommen, in Gruppen von 10 Bienen in Versuchskafige uberfuhrt und uber Nacht in einen Klimaschrank (25 °C) gestellt. Am folgenden Tag werden die Bienen auf ihre Vitalitat hin uberpruft und zwei Stunden vor der Applikation in eine Kuhlkammer (4 ° C) uberfuhrt. Die Bienen befinden sich njetzt in einer Kaltestarre und werden in einer Kuhlbox, zum Applikationsstand gebracht. Vor der Applikation werden die Bienen einer Variante jeweils aus den Beobachtungskafigen in offene Petrischalen gelegt und in der Spritzkammer direkt uberspruht. Zusatzlich wird eine weitere Petrischale mit Filterpapier und 10 toten Bienen fur ruckstandsanalytische Untersuchung aufgestellt. Nach der Applikation werden die immer noch in der Kaltestarre befindlichen Bienen anschliesend in die Kafige zuruckgesetzt und anschliesend wieder zuruck in den Klimaschrank (25 °C) gebracht. Bonituren auf Verhalten, Vitalitat und Mortalitat der Bienen werden 2, 4, 24 und 48 Stunden nach der Applikation durchgefuhrt. nNach der letzten Bonitur werden alle toten und lebenden Bienen der verschiedenen Varianten bei -20 °C fur eine die spatere Ruckstandsanalytik eingefroren um aus den Analysen der Ruckstande in toten und lebendigen Bienen Ruckschlusse uber die Metabolisierung der Wirkstoffe und auch weitere Erkenntnisse fur eine bessere Interpretierbarkeit der Ruckstandsanalysen in Schadfallen mit Verdacht auf Bienenvergiftungen zu gewinnen.Die Daten der Vergleichsbetriebe stellen den Status quo im Pflanzenschutz in Deutschland dar. Der nBehandlungsindex in Mohre und Frischkohl betrug im Durchschnitt der Jahre (2007-2014) bei 6,2 nbzw. 9,2. Mohren wurden vorrangig mit Herbiziden und Frischkohl mit Insektiziden behandelt. Unter ndem Aspekt des Pflanzenschutzes und zur Reduktion der Behandlungsintensitat mit Insektiziden kann nAbbildung 1: Behandlungsindex der Herbizide n(Herbizid-BI) in Abhangigkeit der Vorfrucht nin den Vergleichsbetrieben fur Mohre, n2007-2014, in Deutschland, ungleiche nBuchstaben symbolisieren signifikante Unterschiede n(p<0,05), nBlattfrucht=58, nGemuse=28, nnHalmfruchte=115 n208 72. ALVA-Tagung, Seminarhotel Wesenufer, 2017 nder Fruhkohlanbau empfohlen werden. Im Kohl- und Mohrenanbau konnen Halmvorfruchte Schadlingsbefall nvorbeugen. Die Mittelaufwandmengen wurden vorrangig bei Herbizidanwendungen reduziert nIn beiden Kulturen wurden Abweichungen vom notwendigen Mas verzeichnet. Die Pflanzenschutzberatung nsowie die regelmasige Durchfuhrung von Bonituren konnen Pflanzenschutzmittelanwendungen ndem notwendigen Mas naher bringen und die Umsetzung des IPS in der Praxis verbessern. nFur die Ausschopfung nichtchemischer Masnahmen sind Praxisdemonstrationen und der intensive nAustausch zwischen Wissenschaft und Praxis notig, genauso wie Forschungsforderung zur Entwicklung nneuer und Optimierung bestehender integrierter Verfahren und neuer Wirkstoffe. Vorbildhaft nwird der IPS von den Demonstrationsbetrieben u. a. in den Kulturen Mohre und Weiskohl, seit n2014 umgesetzt. Die Betriebe werden individuell und intensiv betraten, um Pflanzenschutzmittelanwendungen nauf das notwendige Mas zu beschranken. Hierfur werden Bonituren unter Nutzung von nSchadschwellen, Warndiensthinweisen und Monitoringverfahren durchgefuhrt.

Potential von Pflanzenextrakten als biologisches Repellent gegen Vogelfraß

Die Zusammensetzung der Ackerunkrautflora entspricht einer Anpassung an die standortspezifischen Umweltbedingungen, dem Produktionsverfahren hinsichtlich insbesondere der Fruchtfolge und Bodenbearbeitungstechnik, sowie dem jeweiligen Herbizidmanagement. Da die Art und Intensität der Unkrautflora einen erheblichen Einfluss auf die Ertragsfähigkeit und Wirtschaftlichkeit im Ackerbau ausübt, sollte die Produktionstechnik eine nachhaltige Zunahme des Unkrautbesatzes vermeiden. Dies gilt insbesondere für die Art und Intensität der chemischen Unkrautregulierung. In einem Langzeitversuch bei Zurnhausen (11.769° öL., 48.426° nB., WGS84), Landkreis Freising wird seit 2006 der Einfluss einer unterschiedlichen Pflanzenschutzmittelintensität in einer Fruchtfolge mit Winterweizen, Wintergerste und Silomais untersucht. Die vollständige, stationäre Fruchtfolge wird zudem unter dem Regime einer tief-wendenden und nicht-wendenden Bodenbearbeitung durchgeführt. Der Exaktversuch wird auf Großparzellen mit je 60 m2 in vierfacher Wiederholung nach den Vorgaben der einschlägigen EPPO-Richtlinien durchgeführt. Die Herbizidbehandlung erfolgt in den Intensitätsstufen 100 %, 75 % und 50 % Aufwandmenge einer ortsüblichen Herbizidauswahl bzw. -kombination. Die Entwicklung der Unkrautflora wird durch Auszählungen vor dem jeweiligen Herbizideinsatz erfaßt. Der Einfluss der Herbizidbehandlungsintensität auf das Unkrautspektrum und die Unkrautbesatzdichte wird in Abhängigkeit von der Art der Grundbodenbearbeitung detailiert dargestellt und hinsichtlich den Anpassungspotenzial der Herbizidaufwandmenge diskutiert. Hierzu werden auch die erhobenen Ertragsdaten und die Produktionswirtschaftlichkeit herangezogen.

Natural products against bird damage

The main role of MADS-box transcription factors in plant developmental processes has been well described in the model plant Arabidopsis thaliana. However, little is known about their function in crops of important agricultural and commercial value. Our study aims to investigate their role in two agronomical relevant Rosaceae crops: apple (Malus x domestica Borkh.) and strawberry (Fragaria vesca). nExpression studies using qPCR and RNA seq have identified two apple Dormancy Associated MADS-box (DAM) genes. They group with the StMADS11 clade, and were named MdDAM1 and MdDAM2, the last one discovered ex novo. Real time expression studies in dormant buds collected during the chilling period and chromatin immunoprecipitation (ChIP) analyses confirmed that the genes are downregulated by exposure to cold and MdDAM1 is epigenetically repressed, as it has been demonstrated for Arabidopsis FLC and peach DAM genes. nIn parallel we worked on strawberry MADS-box genes of known function involved in flower development. We chose three MADS-box genes that are homologs of Arabidopsis PISTILLATA and AGAMOUS to perform gene expression and functional analysis using a RNA interference approach to obtain post-transcriptional gene silencing. The positive transgenic lines of each transformation were evaluated at the molecular and phenotypic level. Single gene mutants does not show altered flower phenotype, suggesting a different mechanism of flower development in strawberry, probably due to the peculiar flower structure.The quarantine pest pine wood nematode (PWN) Bursaphelenchus xylophilus, native in North America, can be found in wood and root parts of infected conifer trees with focus on Pinus species. At the beginning of the 20 century this species was introduced into Japan supposedly with timber imports where it induced pine wilt expression on susceptible native pine species. Further outbreaks outside Europe are reported from China, Korea, Taiwan and Mexico. In 1999 PWN was found in Portugal, which today is declared as complete infested, since followed by first single tree outbreaks in Spain. The European Union (EU) member states have to undertake measures to prevent further spread of this nematode according to the emergency measures of the EU Commission.The box tree pyralid Cydalima perspectalis (Walker 1859) is an invasive alien moth from East Asia which occurs in Central Europe since 2007. It is an insect pest on plants of the genus Buxus, causing serious damage. Because of the rapid spread in Germany and nearby countries like Switzerland, one part of this study was testing different ways of eco-friendly regulation with commercially available beneficials and biological control agents.1 Julius Kühn-Institute, Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Braunschweig, Germany. 2 Geisenheim Research Center, Section Phytomedicine, Geisenheim, Germany. 3 Área de Genética, Facultad de Ciencias, Universidad de Málaga, Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora (IHSM-UMA-CSIC), Málaga (Spain). 4 Suez Canal University, Faculty of Agriculture, Ismailia, Egypt. Email of corresponding author: namis.eltlbany@jki.bund.deExcessive use of mineral nitrogen (N) fertilizer is a common practice in rice-wheat rotations in southeastern China. At the same time N use efficiencies (NUEs) in these rice-based cropping system are very low (Peng et al., 2006). The consequences are high N losses from arable land to water bodies (surfaceand groundwater) and to the atmosphere (Richter and Roelcke, 2000). To investigate the scope and scale of reductions in mineral N fertilizer inputs, demonstration field experiments on farmers’ field sites were conducted for three consecutive winter wheat-summer rice double crop rotations in two counties of Jiangsu Province from 2008 to 2011. Results from the first two years are presented here. NUEsPolycyclic aromatic hydrocarbons (PAHs) are important environmental pollutants which often persist in soil. The biochemistry of microbe-driven degradation of PAHs is well-studied though less is known about abiotic soil environmental factors influencing the microbe-phenanthrene interaction. Since minerals and charcoal are major soil components we matured different microbial communities in artificial soils based only on variation in the mineral content (montmorillonite, illite, ferrihydrite) and presence of charcoal for 2 years after addition of Luvisol microorganisms and sterile manure. Established microbial communities in soils were exposed to PAHs’ model compound phenanthrene (2 mg/g) to study microbial functionality depending on soil composition. Furthermore, litter which was previously shown to enhance microbial activity was added to the soils (1 wt%). Both treatments with corresponding controls were further incubated for 63 days with sampling on day 0, 7, 21 and 63. A natural Luvisol soil was treated similarly for control. Fingerprints by denaturing gradient gel electrophoresis (DGGE) based on 16S rRNA or ITS gene fragments, respectively, amplified from extracted total community DNA were generated. The presence of phenanthrene-degradative genes was screened by PCR-Southern Blot detection and soil treatments were subjected to a chemical phenanthrene analysis. DGGE fingerprints revealed that the addition of phenanthrene and litter caused a shift in microbial community composition. Differences in bacterial response to phenanthrene were seen depending on litter addition and soil composition. The incubation time was determined as additional influencing factor. Furthermore, a dominance of a specific genotype for phenanthrene degradation is assumed based on PCR-Southern Blot analysis.1 Julius Kühn-Institute Federal Research Centre for Cultivated Plants (JKI), Institute for Epidemiology and Pathogen Diagnostics, Messeweg 11-12, D-38104 Braunschweig 2 Institute of Crop Science and Resource Conservation, Soil Science and Ecology, University of Bonn, Nussallee 13, D-53115 Bonn 3 Institute of Bioand Geosciences 3, Agrosphere, Forschungszentrum Jülich GmbH, D-52425 Jülich Email of corresponding author: sven.jechalke@jki.bund.de

Assessing the repellent effect of substances to prevent bird damage to corn seeds and seedlings

The 8th European Vertebrate Pest Management Conference was held 26-30 September 2011 in Berlin, Germany.xa0 It was organised by the Vertebrate Research Group of Julius Kuhn Institute, Federal Research Centre for Cultivated Plants and the Faculty of Agriculture and Horticulture of Humboldt University. The Conference is a biennial meeting of people interested in various aspects of vertebrate pest management. Overabundant vertebrate populations can be responsible for crop loss, public and animal health concerns, structural damage and confl icts with conservation interests. The conference is a forum for all involved in basic research in vertebrate biology, ecology, methodology, legislation and the application of these topics in wildlife management. The intention of the meeting was to foster the interaction of experts from Europe and beyond specializing in diff erent fi elds of applied and basic vertebrate research because thorough knowledge of all relevant aspects is a vital prerequisite to make informed decisions in vertebrate pest management. This book of abstracts summarizes all contributions that were presented in 9 symposia: 1) Fertility control in vertebrates, 2) Invasive vertebrates, 3) Management of birds, 4) New tools and methods - alternatives to anticoagulants including a workshop, 5) Population dynamics and management of mammals, 6) Rodenticide resistance and management of commensal rodents, 7) Vertebrate management in developing/emerging countries, 8) Wild boar biology and management, and 9) Zoonotic diseases in vertebrates.