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.
1996
Forfattere
Anne Falk ØgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Anne Falk ØgaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Arnstein Orlund Øystein AustaråSammendrag
During 1987-90 heavy infestations of Sitka spruce (Picea sitchensis) plantations by the green spruce aphid Elatobium abietinum were reported from the coastal areas of Møre and Romsdal county, Norway. Annual growth ring width analyses in 1992 showed that minimum growth ring width occurred 6 years after the first infestation. For trees with breast height diameters more than or equal to 20 cm, the loss in diameter increment amounted to an average of 40.5% for 1988-95 compared to control trees (loss equals 3.2 years of normal growth). Growth loss was less pronounced for smaller diameter classes, and the smallest trees even exhibited an increase in increment during the first years of infestation. Possible reasons for different growth patterns are discussed.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Shabani A.O. Chamshama A.G. Mugasha Bjørn LangerudSammendrag
Det er ikke registrert sammendrag
Forfattere
Shabani A.O. Chamshama Bjørn Langerud A.G. MugashaSammendrag
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Forfattere
N.E. Pedersen B. BraskerudSammendrag
Det er ikke registrert sammendrag
Forfattere
Ingvald RøsbergSammendrag
Det er ikke registrert sammendrag
Sammendrag
A commercial extract of neem (NeemAzal-T) and a simple extract of pulverized seeds extracted in warm water were tested against the cabbage pest Mamestra brassicae L. Gravid cabbage moth females were given a choice between sprayed and unsprayed plants for oviposition during 9 days. Second instar larvae were caged on plants and exposed to a series of neem concentrations (leaf dip assay) and to neem applied to the roots (systemic uptake). Residual activity of NeemAzal-T was tested by caging 2nd instar larvae on plants that had been sprayed with neem solutions one hour to three weeks in advance. Oviposition was reduced to half the number of eggs per plant by the neem treatment. The number of eggs that hatched was not affected by the neem treatment, but development of these larvae was strongly inhibited and all larvae in the neem treatment died within two weeks without reaching 2nd instar. The concentration of the active ingredient azadirachtin-A (the azadirachtin component in NeemAzal-T) needed to protect plants from damage by 2nd instar larvae was 8 "g ml-1. The lethal doses for 2nd instar larvae were determined by probit analysis to be 6.2 and 11.2""g ml-1 for LC50 and LC95 respectively. NeemAzal-T protected plants from damage for at least 3 weeks if applied before oviposition, or at least 2 weeks if applied against 2nd instar larvae. In these studies, neem inhibited oviposition, larval development and feeding, and greatly increased mortality.
Forfattere
Lars Sandved Dalen Øystein Johnsen Gunnar OgnerSammendrag
Det er ikke registrert sammendrag