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.
2007
Sammendrag
We evaluated direct and interactive effects of light quality and intensity, temperature and light, diurnal rhythms, and timing of high relative humidity during long day lengths on sporulation of Bremia lactucae, the causal agent of lettuce downy mildew, using inoculated lettuce seedlings and detached cotyledons. Suppression of sporulation by light was strongly dependent upon temperature and there was little suppression at "10°C. The most suppressive waveband was in the range from 400 to 450 nm, although a lesser effect of wavebands from 450 to 500 and 500 to 550 nm could be detected. At 15°C, near the lower threshold for suppression of sporulation by light, a clear diurnal pattern of sporulation was observed independent of light and darkness. This diurnal rhythm potentially could interact with light and temperature to confound the results of controlled environment studies, and may be the controlling factor in timing of sporulation at low temperatures. Forecasting models that currently use sunrise and sunset to delimit periods conducive to sporulation can be adapted to short nights and extended twilight conditions by incorporating the effects reported herein. Additionally, models of sporulation could be adapted to better reflect a decrease or absence of the suppressive effect of light at
Sammendrag
Varsling av bladskimmel i grønnsaker ble beskrevet
Sammendrag
Virulence characteristics of Bremia lactucae populations from lettuce crops in the southeast and southwest of Norway from 2001 to 2005 were studied in relation to virulence factors (v-factors) and virulence phenotypes (v-phenotypes). The frequencies of 19 v-factors were analysed, and phenotypic diversity was calculated in relation to v-factors and v-phenotypes. A total of 39 different v-phenotypes were identified from the 58 samples analysed. Four of these were identical with the previously denominated races Bl:17, 18, 22 and 24. The most commonly occurring v-factors were v1, v2, v4, v5/8, v6, v7, v10, v11, v12, v13 and v18. V-factor v17 was not present in any of the tested isolates and v36 was found only once. V-factor v38 was first seen in 2004, coinciding with the observations of broken resistance in many cultivars. The population of B. lactucae in Norway was diverse, but not considerably different from other European populations of this pathogen.
Sammendrag
Virulens for salatbladskimmel i Norge ble presentert
Sammendrag
Foredraget presenterer resultater fra forsøk der virkningen av kontinuerlig belysning på fekunditet, utvikling og overlevelse hos veksthusmellus (Trialeurodes vaporariorum) ble undersøkt.
Sammendrag
Results from trials with the use of Macrolophus caliginosus on tabacco bankerplants to control whiteflies (Trialeurodes vaporariorum) in cut roses in a commercial greenhouses were presented.
Sammendrag
For at en fremmed art skal godkjennes til bruk i biologisk bekjempelse må det gjennomføres grundige studier av bl.a. utbredelse og etableringspotensial i Norge. Rovtegen Orius laevigatus, rovmidden Neoseiulus californicus og nyttenematoden Heterorhabditis bacterophora har vært brukt i biologisk bekjempelse før 2001, da den nye godkjenningsordningen for nytteorganismer ble innført. Artene ble imidlertid ikke godkjent ved vurderingen i 2001. Begrunnelsen var uklar systematikk, fare for genetiske innblandinger, og usikkerhet rundt naturlig utbredelse og etableringspotensial, og at artene ikke var påvist i Norge. Næringen ønsker å få de 3 artene tilbake på markedet. I 2007 gjennomførte vi derfor en kartlegging for å undersøke om O. laevigatus, N. californicus og H. bacteriophora har etablert seg i Norge. Det er samlet inn prøver både i områder der artene har vært brukt og i andre områder med mildt klima. Prøvene ble tatt i habitat som så langt det var mulig tilsvarer artenes habitat i det naturlige utbredelsesområdet. Det ble funnet 91 tegearter, men O. laevigatus ble ikke ble funnet. Det er funnet en del rovmidd, og nyttenematoder. Identifisering av artene vil bli gjort i februar 2008. Kuldetoleranseforsøk med 2 populasjoner fra hver av artene O. laevigatus og N. californicus er startet, og vil avsluttes i mai 2008.
Sammendrag
Foredrag om låge dosar av koparfungicid mot bladflekksjukdomar i solbær.
Forfattere
Inger Sundheim Fløistad Marit Helgheim Jan Netland Joralv Saur Kirsten Tørresen Kjell WærnhusSammendrag
Det er ikke registrert sammendrag
Forfattere
Arne Hermansen Maria Herrero Elisa Gauslå Jafar Razzaghian Ragnhild Nærstad Sonja KlemsdalSammendrag
Carrot roots with cavity spot lesions from 8 different counties in Norway were sampled and Pythium species were isolated on selective medium. Pythium spp. were characterised morphologically and by species-specific PCR. Laboratory experiments with inoculations of carrot roots were performed. A total of 130 isolates out of 230 Pythium-like isolates tested with PCR were identified as pathogenic species of Pythium. These were P. intermedium (29 %), P. sulcatum (23 %), P. sylvaticum (16 %), P. violae (15 %) and a possible new Pythium species designated P. "vipa" (18 %). There were some difference between geographical regions and ages of cavities regarding the frequency of the different species isolated. When rating sunken lesions in the laboratory inoculation experiments, P. "vipa" was the most aggressive and P. violae the least aggressive species. P. intermedium and P. "vipa" caused more discolouration of the infected carrot tissue than the other species. The importance of the different Pythium spp. as agents of cavity spot in Norway is discussed.