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.
2011
Forfattere
Johannes DeelstraSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Atle HaugeSammendrag
Det er ikke registrert sammendrag
Sammendrag
The causative agent of dieback on European ash (Fraxinus excelsior) was first described as Chalara fraxinea based on cultural morphology because no sexual stage of the fungus was known. Later, based on culturing of ascospores of a candidate teleomorph, morphological comparison and nuclear ribosomal internal transcribed spacer sequencing, the sexual stage of C. fraxinea was assigned as Hymenoscyphus albidus, a native and widespread species in Europe. Recently, the morphological species concept of H. albidus was shown to cover two species that cannot be separated from each other based on teleomorph characters, but which can be distinguished by several DNA markers. As a result, the strains causing ash dieback were reassigned as H. pseudoalbidus. The closely related H. albidus is presumably a non-pathogenic endophyte, but pathogenicity tests to confirm this hypothesis have not yet been performed. Genotyping of herbarium specimens has shown that H. pseudoalbidus was present in Switzerland for at least a decade prior to the epidemic outbreak in Europe. The origin of the ash dieback pathogen, and the general importance of correct pathogen identification to development of effective disease control, are discussed.
Forfattere
Inger Sundheim FløistadSammendrag
Det er ikke registrert sammendrag
Sammendrag
For å opprettholde et høyest mulig avlingsnivå i andre engår er det fra en tidligere serie kjent at førsteårs frøeng av raigras bør stubbes lavt og frøhalmen fjernes snarest mulig etter tresking. I en ny høstbehandlingsserie, hvor det ble stubbet lavt og halmen ble fjernet, ble de høyeste frøavlingene, og best lønnsomhet, i middel for forsøk på Landvik (Aust-Agder) og i Larvik (Vestfold), oppnådd på ruter som var N-gjødsla like etter tresking (4 kg N/daa) og som ikke ble avpussa seinere, men sprøytet mot overvintringssopp (100 mg Acanto Prima/ daa) i perioden 10-20. oktober. De foreløpige resulatene gir grunn til å stille sprøsmål ved om frøeng av raigras egner seg for fôrutnyttelse om høsten.
Forfattere
Trygve S. Aamlid Lars Tørres HavstadSammendrag
Det er ikke registrert sammendrag
Forfattere
Agnar Kvalbein Trygve S. AamlidSammendrag
Det er ikke registrert sammendrag
Forfattere
Lars Tørres HavstadSammendrag
Seed yield of perennial ryegrass normally decrease from the first to the second seed-harvesting year. In order to maintain a high seed yield in the second year crop different treatments in autumn / spring, after harvesting first year crop, were evaluated in two different series with Norwegian tetraploid forage-type cultivars of hybrid- and perennial ryegrass during 2006-2010. Treatments included nitrogen application (both series), treatments of straw (series 1) and regrowth (both series) and spraying against winter diseases (series 2). On average for three trials, straw chopping and spreading during the combining process reduced seed yield with 10 per cent compared to plots where straw had been removed. It is recommended to remove straw soon after harvest and keep stubble height during combining as low as possible. Except for one year (series 2), when the seed crops suffered from an early summer drought (poor utilization of applied spring nitrogen), it was not necessary to apply nitrogen in autumn in order to maximize seed yield. While removal of regrowth in autumn did not normally have any positive influence on the following years seed yield, the highest seed yield in one field was found on plots where regrowth had been cut to 5 cm and removed in early spring. Burning of stubble and regrowth in early spring may harm the plants and should be avoided. Plots being sprayed against winter diseases in late autumn (10 -20 October) produced the highest seed yields in series 2, and was economical beneficial, but further testing is necessary before recommendation for use in practical seed production.
Forfattere
Lars Tørres HavstadSammendrag
Det er ikke registrert sammendrag