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.
2009
Sammendrag
Red stele in strawberry is caused by the oomycete Phytophthora fragariae. To prevent the introduction of the pathogen to Norway, it has been prohibited to import planting material of Fragaria spp. to the country since 1986. During 1995 to 1997 the Food Authority had a country-wide survey to reveal if P. fragariae was present. The pathogen was found in three separate regions: (i) Hedmark County, along the Mjøsa lake; (ii) Aust-Agder and Vest-Agder Counties, in coastal areas; (iii) Rogaland and Hordaland Counties, along the western border between the two counties. In the latter area there were clear indications of spread of infected plant material from a small certified nursery where P. fragariae was detected. All strawberry farms that had received plants from the nursery were thoroughly investigated and further sales of planting material was stopped. All other incidences in the 1995-97 survey were among strawberry fruit producers. In 2006 and 2007 there were two new detections of red stele in Vest-Agder, and one of the growers had produced and forwarded non-certified planting material to other strawberry growers. In 2008, a new country-wide survey was initiated, and the pathogen was found at a few new production sites for strawberry fruits in Hedmark and at one site in Vestfold County (in south eastern Norway). In 2009, red stele was also discovered at one site in Møre og Romsdal County (in western Norway). Totally, red stele has been found at 19 production sites in Norway. Since the mid 1990"s there have been no discoveries of red stele among certified plant producers. Sites where P. fragariae has been detected may continue to produce strawberry fruit for sale, but all production of strawberry plants or other planting material for further distribution is prohibited. For strawberry production on soil infested with P. fragariae, buffer zones to neighboring fields and creeks/rivers are required. No strawberry production can take place in the buffer zones, and normally the zones should be at least 100 m wide, but topographic and other conditions locally may increase or decrease the width of the zones. There are also restrictions on sharing machinery and equipment with other farms, and soil from infested farms may not be moved out of the farm. Testing of plant material is done by a root tip bait test and PCR.
Forfattere
Arne StensvandSammendrag
Det er ikke registrert sammendrag
Forfattere
Margarita Novoa Garrido T.M. Steinum C.L. Marolda M. A. Valvano H. SørumSammendrag
Organic acids are being used in animal husbandry due to their positive effects on overall health and growth rate in animal husbandry. However, little is known about the long-term effects of organic acids on the normal microbiota. In this work, an Escherichia coli strain isolated from a healthy pig was passed weekly for 20 months in medium with and without formic acid (FA) to investigate the effects of long-term exposure to organic acids. Passages were made using buffered medium at pH 5.25 and 6.1 with and without FA. Colonies showing reduced O antigen lipopolysaccharide production and increased susceptibility to FA were isolated after 12 months exposure to FA at pH 5.25 and after 20 months exposure to FA at pH 6.1. Adaptation to acid and bacterial growth was strongly affected by FA at pH 5.25. Also, after 2 months of serial passages, we observed colonies exhibiting multicellular behaviour, with production of fimbriae and an extracellular matrix. We conclude that long-term exposure to FA of an E. coli isolate from the normal intestinal microbiota is associated with various changes in the bacterial cell surface involving reduced O antigen expression and increased extracellular matrix production together with increased susceptibility to FA.
Forfattere
Anne Falk ØgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Sissel Hansen Grete Lene SerikstadSammendrag
Det er ikke registrert sammendrag
Sammendrag
Denne rapporten er gjort på oppdrag for SFT sitt prosjekt Klimakur 2020. Den belyser faktorer som bidrar til redusert N-effektivitet i husdyrproduksjon og risikoen for utslipp av lystgass. Hovedvekt er lagt på muligheter for bedre utnytting av husdyrgjødsel og fokus på å se hele gardsdrifta i sammenheng; økt lagerkapasitet for lokalt å kunne sikre vårspredning av husdyrgjødsel; bedre handtering av husdyrgjødsel og gjødselplanlegging. Da det meste av gjødsla spres om våren og sommeren vil bedre lagerkapasitet i seg selv ikke være nok til å bedre utnyttingen av husdyrgjødsel generelt. Økt fokus på optimale spredetidspunkt og spredemengder for gjødsel og bedre spredeutstyr vil kunne redusere risiko for ammoniakktap betydelig. Det totale N-tapet og risikoen for lystgassutslipp er avhengig av at det tas hensyn til N i husdyrgjødsel i gjødslingsplanlegginga. De fleste melkeproduksjonsgårder i Norge har i dag et netto overskudd av nitrogen. Plantenes mulighet til å utnytte tilført nitrogen og forutsetningene for lystgassutslipp er også påvirket av forholdene i jorda. I våt - dårlig drenert- jord og i pakket jord reduseres utnyttelsen, nitrogeneffektiviteten og faren for tap øker.
Sammendrag
General questions that arise while investigating hydrological extremes are whether these have distinct spatial and temporal variations and how these variations are linked to mean flow conditions. We analyze a large set of European stream flow series. Based on daily observations we derive annual series of stream flow deciles ranging from the minimum to the maximum, resulting in a set of eleven series for each station representing the year to year variability of the flow regimes....
Forfattere
Lukas Gudmundsson Lena M. Tallaksen Kerstin Stahl Holger LangeSammendrag
Det er ikke registrert sammendrag
Forfattere
Arnstein Staverløkk May-Guri SaethreSammendrag
Året 2008 ble et marihøneår for Bioforsk Plantehelse på Ås. Etter at harlekinmarihøna (Harmonia axyridis) dukket opp i en studie av blindpassasjerer på importerte tujaplanter i 2006, har vi nå funnet bevis for at arten har overvintret og etablert seg i Norge.
Forfattere
Trond Rafoss Knut SælidSammendrag
Overvåkning av pærebrann og feltregistrering av vertplanter for denne plantesykdommen ble i sesongen 2008 gjennomført med mobiltelefon med GPS. En ny spesialutviklet programvare for mobiltelefon, SMILEX, ble benyttet sammen med en digital karttjener, GeoServer, hos Bioforsk, til å overføre registreringene via standarden web feature service transaction (WFS-T). Registreringer foretatt i felt er umiddelbart tilgjenglige for visning i kartklienter som støtter en av standardene WMS, WFS eller KML.