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.
2008
Forfattere
Agnes Van den Pol-van Dasselaar T.V. Vellinga Astrid Johansen E KennedySammendrag
Om utvikling, trender og framtidsutsikter i beitebruk og beitedriftssystem i mjølkeprodukjonen i Nord-vest Europa.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Fredrik Bøhler Andreas Brunner Bernt-Håvard ØyenSammendrag
Målet med denne feltstudien var å analysere høydeveksten hos toppkappede og fristilte trær etter en regulering med toppkappingsmetoden i renbestand av gran 4 vekstsessonger etter behandling. Studieområdene består av tre bestand i Nordmarka i Oslo som ble behandlet i 2001 og oppmålt i 2005. Resultatene tyder på at omstillingen til vertikal vekst hos en grein etter at apikaldominansen brytes, gir redusert toppskuddlengde første året. Denne forsinkelsen blir imidlertid mer enn kompensert ved at greina retter seg oppover slik at total høydeøkning første året er større enn påfølgende år. Variablene som best forklarte toppskuddlengdene hos toppkappede trær, var (1) en avstandsavhengig konkurranseindeks, (2) lokalitetsindeks på prøveflatenivå, (3) høydeforskjell mellom kappehøyde og fristilt tre og (4) høyde før inngrep i forhold til det fristilte treets høyde. Fristilte trær risikerer å bli forbivokst av toppkappede trær selv med et høydeforsprang på 2 m. Dette betyr at metoden bør modifiseres ved bruk i gran i forhold til de anbefalinger som tidligere er gitt for toppkapping i bjørk og furu. På grunn av risiko for at høydeforspranget innhentes, anbefales ikke metoden hvis man ønsker å behandle granbestand lavere enn 3,5-4 m eller hvis man har et mål om en nedtopping (nivellering) i reguleringen
Sammendrag
Tannin-enriched extracts from raspberry, cloudberry and strawberry were analysed by liquid chromatography"mass spectrometric (LC"MS) techniques. The raspberry and cloudberry extracts contained a similar mixture of identifiable ellagitannin components and ellagic acid. However, the strawberry extract contained a complex mixture of ellagitannin and proanthocyanidin components that could not be adequately resolved to allow identification of individual peaks. Nevertheless, the negative ESI-MS spectra obtained by direct infusion mass spectrometric (DIMS) analysis described the diversity of these samples. For example, the predominance of signals associated with Lambertianin C in cloudberry and Sanguiin H6 in raspberry tannin extracts could be discerned and the diversity of signals from procyanidin and propelargonidin oligomers could be identified in the strawberry extract. The dose response for the main ellagitannin-derived signals in the raspberry tannin sample revealed a saturation effect probably due to ion suppression effects in the ion trap spectrometer. Nevertheless, DIMS spectra of whole berry extracts described qualitative differences in ellagitannin-derived peaks in raspberry, cloudberry and strawberry samples. In addition, positive mode DIMS spectra illustrated qualitative differences in the anthocyanin composition of berries of progeny from a raspberry breeding population that had been previously analysed by LC"MS. This suggests that DIMS could be applied to rapidly assess differences in polyphenol content, especially in large sample sets such as the progeny from breeding programmes.
Forfattere
Thomas Hartnik Line Sverdrup John JensenSammendrag
lpha-cypermethrin, a synthetic pyrethroid, is used as an insecticide in agricultural settings, and increasingly replaces organophosphates and carbamates due to lower application rates and lower mammal toxicity. As very little is known about the acute and chronic toxicity for soil living organisms, this study investigated acute and sublethal toxicity of alpha-cypermethrin for four terrestrial invertebrate species in an agricultural soil from Norway. Bioassays with the earthworm Eisenia fetida, the potworm Enchytraeus crypticus, the springtail Folsomia candida and the land snail Helix aspersa were performed according to slightly modified versions of OECD- or ISO-guidelines and resulted in median lethal concentrations (LC50) of >1000 to 31.4 mg/kg and sublethal no-effect-concentrations (NOEC) of 2.51 to 82 mg/kg. A high acute-to-chronic ratio (ACR) was found in especially the earthworms. Interspecies differences in sensitivity may be explained by differences in exposure and differences in metabolisation rate. When based on measured pore water concentrations, terrestrial species appear overall to be about one order of magnitude less sensitive than aquatic species. Effect assessments conducted according to European guideline for risk assessment of pesticides reveal that assessments based on acute toxicity tests are not always conservative enough to warrant environmentally safe concentrations in soil. Mandatory incorporation of sublethal toxicity data will ensure that also in regions with temperate climate effects of pesticides on populations of soil living organisms are unlikely.
Sammendrag
Alpha-cypermethrin, a synthetic pyrethroid, is used as an insecticide in agricultural settings and is increasingly replacing organophosphates and carbamates because of lower application rates and lower toxicity to mammals. Because very little is known about the acute and chronic toxicity of this compound for soil-living organisms, the present study investigated acute and sublethal toxicity of alpha-cypermethrin for four terrestrial invertebrate species in an agricultural soil from Norway. Bioassays with the earthworm Eisenia fetida, the potworm Enchytraeus crypticus, the springtail Folsomia candida, and the land snail Helix aspersa were performed according to slightly modified versions of Organization for Economic Cooperation and Development (Paris, France) or International Organization for Standardization (Geneva, Switzerland) guidelines and resulted in median lethal concentrations of greater than >1,000 to 31.4 mg/kg and sublethal no-observed-effect concentrations of 2.51 to 82 mg/kg. A high acute to chronic ratio was found, especially in the earthworms. Interspecies differences in sensitivity may be explained by differences in exposure and differences in metabolization rate. When based on measured pore-water concentrations, terrestrial species overall appear to be approximately one order of magnitude less sensitive than aquatic species. Effect assessments conducted according to European guideline for risk assessment of pesticides reveal that assessments based on acute toxicity tests are not always conservative enough to determine environmentally safe concentrations in soil. Mandatory incorporation of sublethal toxicity data will ensure that in regions with temperate climate, the effects of pesticides on populations of soil-living organisms are unlikely.
Forfattere
Espen GovasmarkSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Matias Pasquali Erik Lysøe Andrew Breakspear Kyeyong Seong Jon Menke Jin-Rong Xu H. Corby KistlerSammendrag
To understand mycotoxin accumulation and the infection cycle of the wheat head blight pathogen Fusarium graminearum sensu stricto,fungal gene expression profiles were monitored during plant infection. Strains containing mutations in genes for three transcription factors were found to control deoxynivalenol (DON) accumulation in planta and pathogenicity. Expression profiles were compared between wildtype and these mutants during infection of wheat. Mutants deleted for the StuA gene were greatly decreased in sporulation and produced no perithecia in culture. Unlike "stuA mutants in F. oxysporum, F. graminearum "stuA mutants were greatly reduced in pathogenicity. Reduced pathogenicity may be due to decreased DON levels in planta, which in the mutant were