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.
2012
Forfattere
M Ashraful Islam Goutam Kuwar Jihong Liu Clarke Dag-Ragnar Blystad Hans Ragnar Gislerød Jorunn Elisabeth Olsen Sissel TorreSammendrag
Abstract Strict control of morphogenesis is essential in production of potted poinsettia. Commonly, this is obtained by the use of plant growth retardants (PGRs), often in combination with early morning temperature drops. Due to negative effects on human health and the environment, the use of PGRs is becoming restricted. Also, energy-saving growth regimes and periods of high temperatures limit effective use of temperature drops. In the present study the use of a high proportion of blue (B) light provided by light emitting diodes [LEDs, 20% blue (B), 80% red (R)] was compared with traditional high pressure sodium (HPS) lamps (5% B) providing similar phytochrome photostationary state to produce compact poinsettia plants. Both in the greenhouse and growth chamber, all cultivars were 20–34% shorter for LED compared to HPS grown plants. Also, leaf and bract area as well as chlorophyll content and total dry matter accumulation were lower under LED. The LED did not delay bract color formation, visible cyathia and flowering compared to HPS, and no difference in post production performance (cyathia/bract abscission or necrosis) between the two light treatments was found. The effect of end of day-red (EOD-R) lighting combination with LED and HPS supplemental lamps during the photoperiod in the greenhouse was also investigated. Reduced stem extension (13%) was observed under HPS only and for one of the two cultivars tested, whereas under the LED regime, there was no effect of EOD-R lighting.
Forfattere
Tor Erik Brandrud Klaus Høiland Halvor Solheim Leif SundheimSammendrag
Det er ikke registrert sammendrag
Forfattere
Anna Birgitte MilfordSammendrag
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Sammendrag
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Forfattere
Fride Høistad Schei Hans Blom Ivar Gjerde John Arvid Grytnes Einar Heegaard Magne SætersdalSammendrag
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Sammendrag
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Forfattere
Aruppillai Suthaparan Sissel Torre Leiv M. Mortensen Hans Ragnar Gislerød Knut Asbjørn Solhaug Arne Stensvand David M. GadourySammendrag
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Forfattere
Jonathan Edward Colman Diress Tsegaye Alemu Christian Pedersen Ruben Eidesen Herbjørg Arntsen Øystein Holand Alex Mann Eigil Reimers Stein Ragnar MoeSammendrag
Interspecific interaction among sympatric ungulates is important in management and conservation. We investigated behavioral interference between sympatric wild or semidomestic reindeer (Rangifer tarandus tarandus) and sheep (Ovis aries) in two field studies and one enclosure experiment. For free-ranging wild and semidomestic reindeer, interference between the two species increased with decreasing distances, occurring only at less than 200 m and 30 m, for wild and semidomestic reindeer, respectively, and neither species consistently dominated the other. In a controlled, duplicated experiment we tested interference and confrontations at the feeding patch level among semidomestic reindeer and sheep within 40 × 50 m enclosures. When new reindeer or sheep were introduced into enclosures already occupied by reindeer, new reindeer resulted in significantly more interference and confrontations among individuals compared to new sheep; i.e., intraspecific interference was more prevalent than interspecific interference at equal densities. For all study areas, confrontations decreased with time after “first encounter,” indicating cohabituation. A sympatric use of pastures was not visually disruptive for recorded grazing behavior for either species.
Forfattere
Igor A. Yakovlev Gustav Vaaje-Kolstad Ari Hietala Emil Stefanczyk Halvor Solheim Carl Gunnar FossdalSammendrag
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Sammendrag
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