Publikasjoner
NIBIOs ansatte publiserer flere hundre vitenskapelige artikler og forskningsrapporter hvert år. Her finner du referanser og lenker til publikasjoner og andre forsknings- og formidlingsaktiviteter. Samlingen oppdateres løpende med både nytt og historisk materiale. For mer informasjon om NIBIOs publikasjoner, besøk NIBIOs bibliotek.
2004
Sammendrag
En rekke skadedyrarter kan være et problem i planteskoler, fordi det produseres mange forskjellige kulturer i veksthus og på friland, samt at det importeres og omsettes store mengder plantemateriale. I de to første artiklene (del I og II) som ble utgitt i Gartneryrket nr. 7 og 8 i 2003 beskrives ulike bekjempelsestiltak mot midd, bladlus, mellus, skjoldlus, sikader, teger og trips på prydplanter i norske planteskoler. Denne artikkelen omfatter bekjempelse av biller, minerfluer, bladveps og sommerfugler.
Sammendrag
The searching efficiency of Encarsia formosa Gahan (Hymenoptera: Aphelinidae) and the control efficiency of E. formosa and Macrolophus caliginosus Wagner (Hemiptera: Miridae) were studied on the hairy poinsettia (Euphorbia pulcherrima Willd.ex Koltz.) cultivar `Lilo" (2030 hairs/cm2, hair length 18.0 mm) and the less hairy cultivar `Sonora" (449 hairs/cm2, hair length 11.8 mm) at 18 - 21oC, in order to evaluate their potential as biological control agents in greenhouse poinsettia production. Inexperienced (less than 24 hours old) E. formosa (EN-STRIP, Koppert B.V.) were observed individually for 7 minutes on poinsettia leaves without whiteflies, using the automatic video tracking system for behavioural studies, EthoVision Color Pro. Their walking speed, walking activity and walking pattern were not influenced by the leaf hairiness. When the temperature was lowered from 20 to 18oC, the mean walking speed decreased by 15%, from 0.52 to 0.44 mm/sec on `Lilo" and from 0.51 to 0.43 mm/sec on `Sonora". The mean walking activity was 89% on `Lilo" and 88% on `Sonora" at 20oC, and was decreased by 6 and 13%, respectively, at 18oC. Temperature did not influence the straightness of the walking path. The control efficiency of E. formosa and M. caliginosus (MIRICAL, Koppert B.V.) was studied on `Lilo" and `Sonora" infested with Bemisia tabaci Gennadius (Homoptera: Aleyrodidae) B biotype in 2 cage experiments at 21oC, and is currently being studied at lower temperatures. E. formosa was introduced when the first whitefly nymphs had reached the 3rd instar, and was released weekly 3 times at a total rate of 4.2 parasitoids/adult whitefly. M. caliginosus was introduced when the first whitefly nymphs had reached the 1st instar, and was released every 2 weeks 3 times at a total rate of 1.5 predatory bugs/adult whitefly. One tobacco plant (Nicotiana tabacum `Xanthi") was placed in each of the cages where M. caliginosus was released. The control efficiency (measured as % reduction of number of immature whiteflies compared to the control when the plants were ready for sale) ranged from 63 to 93% for E. formosa and from 64 to 82% for M. caliginosus. E. formosa gave slightly better control than M. caliginosus on `Sonora", and in one of the experiments with `Lilo". The parasitoids were more efficient, and the parasitism was higher, on `Sonora" than on `Lilo". No damage to green leaves or bracts has been observed on the plants where M. caliginosus was released.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Ingeborg Klingen Nina Trandem Arnulfo Monzón Falguni Guharay Ragnhild Sand Eduardo HidalgoSammendrag
- Insect pathogenic fungi are important naturally occurring mortality factors of pest insects and mites. - Few studies have been made on natural occurrence of insect pathogenic fungi and the effect of management system in Central America. - One study from Norway confirms that management system (organic compared to conventional) is important to the occurrence and prevalence of insect pathogenic fungi in soil in arable fields. - Another study from Norway indicates the importance of pesticide use on the killing capacity of the mite pathogenic fungi N. floridana to T. urticae. - A master study from Nicaragua showed a higher B. bassiana infection level in L. coffeella with increasing shading. More studies are, however, needed to confirm this trend. - In a PhD project at CATIE Nicaragua, naturally occurring insect pathogenic fungi on key coffee pests and the effect of crop management practices on these fungi is under study. - An ongoing master study will reveal the occurrence of insect pathogenic fungi in soil from different coffee growing systems in Nicaragua and Costa Rica.
Forfattere
Håvard Eikemo Sonja Klemsdal Ingvild Riisberg Peter Bonants Arne Stensvand Anne-Marte TronsmoSammendrag
Analysis of 44 isolates of Phytophthora cactorum, isolated from strawberry and other hosts, by AFLP showed that the crown rot pathotype is different from leather rot isolates and from P. cactorum isolated from other hosts. 16 of 23 crown rot isolates, including isolates from Europe, Japan, Australia, and New Zealand, were identical in an analysis based on 96 polymorphic bands from seven primer combinations. Leather rot isolates of strawberry could not be distinguished from isolates from other hosts. The pathogenicity test of all 44 isolates on strawberry plants mostly gave unambiguous results, except for three American isolates, which seemed to have reduced aggressiveness compared to the crown rot isolates. These isolates also differed in the AFLP analysis. Comparing information on the origin of the isolates with results from the pathogenicity test, showed that isolates from strawberry fruits or petioles could be either leather rot or crown rot pathotypes. None of the isolates from hosts other than strawberry caused crown rot symptoms in strawberry.
Sammendrag
Indusert resistens er eit fenomen der plantene sine eigne forsvarsmekanismar vert aktivert ved hjelp av middel som ikkje har direkte effekt på skadegjeraren. Fordelen med bruk av slike middel er at skadegjeraren ikkje bygger opp resistens mot det, og det har effekt mot eit breitt spekter av sjukdomsframkallande organismar. Middel som induserer resistens har vist seg å ha like god effekt mot rotstokkròte og raud marg i jordbær som det mest brukte kjemiske middelet.
Sammendrag
Thrips palmi er en karanteneskadegjører som kan gjøre stor skade i mange kulturer.
Forfattere
Nina Trandem Solveig Aasen Eline B. Hågvar Jørn Haslestad Solveig Haukeland Anita SønstebySammendrag
Artikkelen oppsummerer noen små forsøk som er gjort på biologi, overvåking og skade, samt med nye kjemiske midler, nyttenematoder og utgjerding i årene 2000-2003. Enkelte populasjoner av jordbærsnutebille ser ikke lenger ut til å la seg bekjempe med konvensjonelle plantevernmidler. Utenlandske forsøk har vist at jordbærplanter kan kompensere for opptil 50% avbitte knopper ved å utvikle nye knopper og/eller øke bærstr, men dette ser i liten grad ut til å gjelde norske jordbærplanter. I et økologisk felt som ble fulgt i 4 år, økte antall avbitte knopper per plante sterkt fra første til tredje høstingsår, for så å avta. I det tredje året var oppimot 80 blomsterknopper avbitt per plante. For å overvåke billebestanden i et felt, er registrering av selve billen ved risitng av planter over et hvitt fat en raskere metode enn å telle avbitte knopper, og sier også mer om mulig framtidig skade. Pilotforsøk med utgjerding og nyttenematoder har vist lovende resultater.
Forfattere
Nina Elisabeth Nagy Lars Sandved Dalen D. L. Jones B. Swensen Carl Gunnar Fossdal Toril EldhusetSammendrag
Det er ikke registrert sammendrag
Forfattere
Carl Gunnar Fossdal Øystein Johnsen Nina Elisabeth Nagy R Baumann Jørgen A.B. Mølmann Tore SkrøppaSammendrag
Introduction: Survival and competitive successes of boreal forest trees depend on a balance between exploiting the full growing season and minimising frost injury through proper timing of hardening in autumn and dehardening in spring. Our research indicates that the female parents of Norway spruce adjust these timing events in their progeny according to the prevailing temperature conditions during sexual reproduction. Reproduction in a cold environment advances bud-set and cold acclimation in the autumn and dehardening and flushing in spring, whereas a warm reproductive environment delays these progeny traits by an unknown non-Mendelian mechanism. We are now looking for molecular mechanisms that can explain this “epigenetic” phenomenon. Material and methods: We have performed identical crosses with the same Norway spruce (Picea abies) parent, as discussed by Skrøppa & Johnsen (1994) and Johnsen et al. (1995), in combination with timed temperature treatments during shorter and longer periods from female meiosis, pollen tube growth, syngamy and embryogenesis and tested the progenies for bud-set and frost hardiness. We have followed the transcription of the spruce phytochromes PHYO, PHYP and PHYN and the class IV chitinase PaChi4 using Quantitative Multiplex Real-Time PCR. Results and conclusions: The effect of temperature on Adaptive properties is most likely a response to accumulated heat during embryogenesis and seed maturation. Our first attempt to look for a molecular mechanism has revealed that transcription of PHYO, PHYP and PHYN and the class IV chitinase PaChi4 (relative to alphaTubulin) all show higher transcription levels in progenies born under cold conditions than their full-sibs born under warmer conditions. This result is consistent with preliminary findings that methylation of cytosine in total DNA is higher in progenies reproduce under warm conditions than their colder full-sib counterparts. If these observations are related to methylation or other epigenetic effects, we may explain why progenies with a memory of a past time cold embryogenesis are more sensitive to short days than their full-sibs with a warmer embryonic history.