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
En partssammensatt arbeidsgruppe vurderte i 20062007 omsetningsordningen for melkekvoter. NILF fikk i oppdrag å belyse enkelte sider ved kvoteomsetning og å gi innspill til arbeidsgruppa på utvalgte temaer. Disse temaene gjaldt foretaksøkonomisk lønnsomhet ved kvotekjøp, samfunnsøkonomisk effektivitet og konsekvenser for melkeproduksjonen som næring. Dessuten så en på effekten av kvoteomsetning på strukturutvikling og eventuelle tap ved at driftsbygninger går ut av bruk «for tidlig» som følge av kvoteomsetning. NILF oversendte en skriftlig sammenstilling av innspillene, og denne ble lagt ved arbeidsgruppas rapport. Dette notatet er en bearbeidet versjon av det materialet. Endringene består bl.a. i at vi har utvidet den teoretiske og metodiske drøftinga, presisert en del forutsetninger, strammet opp teksten på en del punkter, lagt inn noen flere kildehenvisninger, og skrevet et sammendrag. Beregningene er kontrollerte og delvis forenkla. Konklusjonene er i hovedsak som i det materialet som ble oversendt arbeidsgruppa. I kapittel 2 presenteres først en metode for å beregne hva en maksimalt kan betale for melkekvote, og viser effekten av tidsperspektiv og regler for salg av kvote. Til dette nyttes stiliserte eksempler. For ytterligere å belyse hovedspørsmålene har vi utarbeidet et sett av kalkyler. Lønnsomheten ved kvotekjøp er vurdert på to måter: • Hvordan er lønnsomheten ved kvotekjøp til en gitt kvotepris under gitte betingelser? • Hva kan betales per liter for kvotekjøp under gitte betingelser?
Forfattere
Gunhild BørtnesSammendrag
Det er ikke registrert sammendrag
Forfattere
Elena A. Ignatova Hans Haavardsholm Blom D.V. Goryunov Irina A. MilyutinaSammendrag
A phylogenetic analysis of ITS1-2 sequences from 117 specimens of Schistidium from Eurasia and North America revealed several new taxa within the genus. Schistidium sibiricum Ignatova & H.H. Blom, S. obscurum H.H. Blom, Köckinger & Ignatova, S. tenuinerve Ignatova & H.H. Blom, S. bakalinii Ignatova & H.H. Blom, S. echinatum Ignatova & H.H. Blom and S. succulentum Ignatova & H.H. Blom are described as new for science. Three new combinations are made: S. canadense (Dupr.) Ignatova & H.H. Blom, S. abrupticostatum (Bryhn) Ignatova & H.H. Blom and S. konoi (Broth.) Ignatova & H.H. Blom. Illustrations are provided for new species. A preliminary key for the identification of Schistidium species known in Russia is given.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Belachew Asalf Arne Stensvand David M. Gadoury Robert C. Seem Andrew Dobson Anne Marte TronsmoSammendrag
Development of ontogenic resistance to powdery mildew (Podosphaera aphanis) in strawberry fruit has not been quantified, and thus cannot be exploited in disease management programs. Four commercially-relevant strawberry cultivars were evaluated for ontogenic resistance to powdery mildew. Fruits were inoculated at one of the four growth stages: flowering, green, white and early pink fruit. There was a significant difference between and within cultivars at the bloom and green stage of inoculations (P ≤ 0.05) for both disease incidence and severity. On average 16.4, 39.5, 48.7, and 60.3 % of the fruits inoculated at bloom developed powdery mildew in cultivars Elan, Korona, Frida and Inga, respectively. None of the cultivars developed powdery mildew when inoculated at the pink stage. It may be concluded that flowers and green fruits of strawberry were much more susceptible to powdery mildew infection than white and pink fruits. The high susceptibility of cultivars at the flower and early green stages seemed coincident with the succulent nature of the fruits at these stages, making it easy for penetration and establishment of mildew. Control measures targeting at these critical windows of fruit susceptibility are likely to reduce yield loss.
Forfattere
Belachew Asalf Tadesse Arne Stensvand David M. Gadoury Robert C Seem Andrew Dobson Anne-Marte TronsmoSammendrag
Development of ontogenic resistance to powdery mildew (Podosphaera aphanis) in strawberry fruit has not been quantified, and thus cannot be exploited in disease management programs. Four commercially-relevant strawberry cultivars were evaluated for ontogenic resistance to powdery mildew. Fruits were inoculated at one of the four growth stages: flowering, green, white and early pink fruit. There was a significant difference between and within cultivars at the bloom and green stage of inoculations (P <0.05) for both disease incidence and severity. On average 16.4, 39.5, 48.7, and 60.3 % of the fruits inoculated at bloom developed powdery mildew in cultivars Elan, Korona, Frida and Inga, respectively. None of the cultivars developed powdery mildew when inoculated at the pink stage. It may be concluded that flowers and green fruits of strawberry were much more susceptible to powdery mildew infection than white and pink fruits. The high susceptibility of cultivars at the flower and early green stages seemed coincident with the succulent nature of the fruits at these stages, making it easy for penetration and establishment of mildew. Control measures targeting at these critical windows of fruit susceptibility are likely to reduce yield loss.
Forfattere
Belachew Asalf Arne Stensvand David M. Gadoury Robert C. Seem Andrew Dobson Anne Marte TronsmoSammendrag
This presentation is on development of age related (ontogenic) resistance to powdery mildew (Podosphaera aphanis) in strawberry fruits. Four cultivars were tested. Flowers and immature green fruits were much more susceptible to powdery mildew than white or pink fruits. No fruits developed mildew if inoculated at the pink stage, and very few at the white stage.
Forfattere
Belachew Asalf Tadesse Arne Stensvand David M. Gadoury Robert C Seem Andrew Dobson Anne-Marte TronsmoSammendrag
Det er ikke registrert sammendrag
Forfattere
Peder Gjerdrum Jarl-Gunnar SalinSammendrag
The Scots pine is widely used for pressure-treated transmission poles. Prior to preservation treatment, all capillary water must be dried off. Natural seasoning in open-air predominates, which implies that most drying takes place during the dry spring and warm summer seasons. The inventory of drying poles represents considerable value in a company’s balance sheet and risk of downgrading. There is risk both for keeping higher inventory than optimal and for treating poles that would not be dried sufficiently. Knowledge of drying times during the annual seasons has been insufficient. The objective of this study has been to work out a model for pole drying, based on a description of the pole itself and climatic observations during drying. The model has then been used to predict optimal drying times for various pole types and climatic conditions, for roofed or sheltered pole inventories, for assisted drying, etc.
Forfattere
R. Linnakoski Z.W. de Beer M. Rousi Halvor Solheim M.J. WingfieldSammendrag
Ophiostomatoid fungi were isolated from Scolytus ratzeburgi infesting Betula pendula and B. pubescens in Norway. Fungi were identified based on morphology, DNA sequence comparison for two gene regions and phylogenetic analyses. The most abundant fungus was Ophiostoma karelicum, suggesting a specific relationship between the fungus, the vector insect and the host tree. Our results suggest that O. karelicum occurs across the geographic range of S. ratzeburgi and its close relatedness to the Dutch elm disease fungi suggests that it could be important if introduced into other parts of the world. Other fungi, only occasionally isolated from S. ratzeburgi, were identified as O. quercus and a novel taxon, described here as O. denticiliatum sp. nov.