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.
2005
Forfattere
Brita Toppe Maria HerreroSammendrag
Rosemjøldogg (Podosphaera pannosa) og agurkmjøldogg (Podosphaera xanthii) er blant de økonomisk viktigste sjukdommer i norsk veksthusproduksjon av henholdsvis roser (Rosa x hybrida) og agurk (Cucumis sativus). Tilgangen på kjemiske mjøldoggmidler er begrenset, men middelprøving viser tilfredsstillende effekt av henholdsvis penkonazole (Topas 100 EC) i roser og imazalilsulfat (Fungaflor 100 EC) i agurk. Alternative midler som bakepulver, grønnsåpe, kalisåpe, neemekstrakt, mineral. og organiske oljer har vist signifikant reduksjon i angrepsgraden av mjøldogg i forhold til ubehandlet kontroll, men noe dårligere effekt enn de kjemiske fungicider. Unntaket er Florina Meldugg og Insektsfjernre konsentrat (mineralolje) som viser like god eller bedre effekt mot agurkmjøldogg enn referansemiddelet imazalilsulfat.
Forfattere
Axel Schmidt Zeneli Gazmend Ari Hietala Carl Gunnar Fossdal Paal Krokene Erik Christiansen Jonathan GershenzonSammendrag
Det er ikke registrert sammendrag
Sammendrag
Studier av tørråtepopulasjonen i Norge fra 2003 bekrefter tidligere års undersøkelser at den er svært variabel både i genotype og fenotype. Andelen av metalaksyl-resistente individer har gått tilbake. Det er påvist en relativt stor andel isolater som tolererer å vokse på 100 ppm propamokarb, men det er ikke konstatert resistensproblemer i felt. Krysningstype A2 er ikike påvist blant 110 isolater fra Nord-Norge i 2004, noe som antyder at kjønna formering av tørråtesoppen er sjelden eller fraværende i denne landsdelen. Problemene med tørråte i Sør-Norge var mindre i 2004 enn i de foregående årene. Feltforsøk med ulike strategier i 2004 viste at en kunne bekjempe tørråte med godt resultat både med dynamiske fungiciddoser ved faste intervall og ved sprøyting etter ulike varslingsmodeller. Det var imidlertid vanskelig å påvise sikre forskjeller mellom de ulike strategiene.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
The spruce bark beetle is the most serious pest of mature spruce trees in Eurasia. At low population densities it breeds in weakened or newly dead trees, but at high densities it becomes a tree killer. The exact factors triggering outbreaks are not fully understood, but climatic variables are important candidates. Populations in SE Norway have been monitored since 1979. Various time series methods are used to explore the role of climate in outbreaks of the spruce bark beetle in space and time, and to estimate the distribution of bivoltism under different scenarios of climate change. Large windfall events appear to be a major synchronizer of beetle outbreaks in areas subjected to regionalized weather systems, and the northern border of bivoltism may be moved towards north as a function of increasing temperature. Preliminary models of the population dynamics emphasize the frequency of large windfall events and phenological changes due to temperature increase. Final aims are to estimate the regional risks of forest damage under different scenarios of climate change, and to describe practices that may reduce the impact for forest managers.
Sammendrag
At least three mechanisms are known to cause synchrony among spatially separated insect populations: 1) dispersal among populations, 2) synchronous stochastic effects, often referred to as the Moran effect, and 3) trophic interactions with other species that are either themselves synchronized or mobile.The present study brings in the role of insect taxa for spatial synchrony. The spatial synchrony observed in several North American and Eurasian epidemic bark beetles was compared with patterns of synchrony in outbreaks of defoliating forest Lepidoptera, revealing a marked difference between these two major insect taxa.The bark beetles exhibited a generally lower degree of spatial synchrony than the Lepidoptera, possibly because bark beetles are synchronized by different weather variables that are acting on a smaller scale than those affecting the Lepidoptera, or because inherent differences in their dynamics leads to more cyclic oscillations and hence more synchronous spatial dynamics in the Lepidoptera. Among the epidemic bark beetles tested, spatial synchrony of outbreaks in the Eurasian spruce bark beetle Ips typographus was significantly higher than for the other species.
Sammendrag
This paper describes the use of quantitative real-time PCR for monitoring colonization of birch wood (Betula pubescens) by the white-rot fungus Trametes versicolor in an EN113 decay experiment. The wood samples were harvested after 4, 8, 12, 16 and 20 weeks of incubation.The mass loss was in the range of 440%. Chitin and ergosterol assays were conducted for comparison. Second-order polynomial fits of the mass loss of decayed wood versus chitin, ergosterol and DNA gave correlations (r2) of 0.87, 0.61 and 0.84, respectively. Compared to the other two assays employed, real-time PCR data correlated best with the relative mass loss of decayed samples 48 weeks after inoculation, while the saturation and decline of DNA-based estimates for fungal colonization 1620 weeks after inoculation indicated that the DNA assay is not suited for quantification purposes in the late stages of decay.The impact of conversion factors, extraction efficiency, inhibitory compounds and background levels in relation to the three detection assays used is discussed.
Sammendrag
In spring 2002, extensive damages were recorded in southeast Norway on nursery-grown Norway spruce seedlings that had either wintered in nursery cold storage or had been planted out in autumn 2001. The damages were characterised by leader shoot dieback and necroses on the upper or lower part of the 2001-year-shoot. Gremmeniella abietina and Phomopsis sp. were frequently isolated from the diseased seedlings. RAMS (random amplified microsatellites) profiling indicated that the G.abietina strains associated with diseased nursery seedlings belonged to LTT (large-tree type) ecotype, and inoculation tests confirmed their pathogenicity on Norway spruce. Based on sequence analysis of the internal transcribed spacer (ITS) regions of ribosomal DNA, the Phomopsis strains associated with diseased seedlings do not represent any characterized Phomopsis species associated with conifers. Phomopsis sp. was not pathogenic in inoculation tests, this implying it may be a secondary colonizer. ITS-based real-time PCR assays were developed in order to detect and quantify Gremmeniella and Phomopsis in the nursery stock. We describe here the Gremmeniella - associated shoot dieback symptoms on Norway spruce seedlings and conclude that the unusual disease outburst was related to the Gremmeniella epidemic caused by the LTT type on large pines in 2001.
Forfattere
Magnus Karlsson Ari M. Hietala Harald Kvaalen Åke Olson Halvor Solheim Jan Stenlid Carl Gunnar FossdalSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag