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.
2006
Sammendrag
Toxic effects of aluminium (Al) on Picea abies (L.) Karst. (Norway spruce) trees are well documented in laboratory-scale experiments, but field-based evidence is scarce. This paper presents results on fine root growth and chemistry from a field manipulation experiment in a P. abies stand that was 45 years old when the experiment started in 1996. Different amounts of dissolved aluminium were added as AlCl3 by means of periodic irrigation during the growing season in the period 19972002. Potentially toxic concentrations of Al in the soil solution were obtained. Fine roots were studied from direct cores (1996) and sequential root ingrowth cores (1999, 2001, 2002) in the mineral soil (040 cm). We tested two hypotheses: (1) elevated concentration of Al in the root zone leads to significant changes in root biomass, partitioning into fine, coarse, living or dead fractions, and distribution with depth; (2) elevated Al concentration leads to a noticeable uptake of Al and reduced uptake of Ca and Mg; this results in Ca and Mg depletion in roots. Hypothesis 1 was only marginally supported, as just a few significant treatment effects on biomass were found. Hypothesis 2 was supported in part; Al addition led to increased root concentrations of Al in 1999 and 2002 and reduced Mg/Al in 1999. Comparison of roots from subsequent root samplings showed a decrease in Al and S over time. The results illustrated that 7 years of elevated Altot concentrations in the soil solution up to 200 M are not likely to affect root growth. We also discuss possible improvements of the experimental approach.
Sammendrag
Conidia germination of the root pathogen fungi Fusarium sp. and Cylindrocarpon sp. were followed for up to 96 hours in the presence of border cells from newly germinated Norway spruce. The border cells stimulated the conidium germination of both fungi. We postulate that this may be a part of the defence mechanism of Norway spruce against pathogens. The stimulating agent is unknown The stimulating effect was not seen when border cells originated from plants grown in the presence of aluminium
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Forfattere
T. Salo B Stenberg C. Lundström L.S. Jensen S. Bruun A. Pedersen T.A Breland T. Henriksen Audun Korsæth H. Palmason J. GudmundssonSammendrag
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Forfattere
Gudbrand Lien Ola Flaten Audun Korsæth K.D. Schumann J.W. Richardson Ragnar Eltun J. Brian HardakerSammendrag
Målet med denne studien var å jamføre risikoen for økologiske, integrerte og convensjonelle dyrkingssystem. Forsøksdata frå eit dyrkingssystem (1991-1999) på Austlandet vart brukte saman med budsjettal frå gardsbruk. Empirisk fordeling av nettoinntekt for ulike dyrkingssystem vart estimert ved hjelp av ein simuleringsmodell. Resultata syner at det økologiske systemet hadde størst variasjon i nettoinntekt, men med gjeldane tilskotsordningar og meirprisar for økologiske varer vert dette det mest økonomiske alternativet.
Forfattere
Audun KorsæthSammendrag
Det er ikke registrert sammendrag
Forfattere
Guro BrodalSammendrag
A survey of the loose smut frequencies in certified barley seed lots in Norway during 1997"2002 showed that the disease has become more prevalent and has occurred at higher infection frequencies in recent years. Laboratory analyses (embryo method) of barley seeds harvested in 2001 and 2002, including both certified and farm saved seed, showed a large number of infected seed lots with higher than expected infection frequencies. One lot of farm saved seed (cv. Otira) from 2002 had 32% seed infection. Unexpectedly high loose smut infection frequencies recorded in fields sown with carboxin treated barley seed suggest a reduced effectiveness of the fungicide. A seed treatment experiment was conducted in 2002 using both greenhouse and field trials with two infected seed lots (cv. Otira with 14.4% and cv. Fager with 6.9% infected seeds) to evaluate and compare the effect of Fungazil C (carboxin + imazalil) and Premis Robust (triticonazol + imazalil) against loose smut. Fungazil C at normal rates reduced loose smut frequencies by approximately 50% or less. At twice the normal rate, loose smut symptoms were reduced by 60-80%. Premis Robust showed more effective loose smut control, but did not confer complete control.
Sammendrag
In a preliminary experiment terminal stem cuttings (4 – 5 cm) were collected in the spring (May) from a wild population of lingonberry near Holt Research Center, Tromsø, Norway. The cuttings were rooted in peat mixed with 30% perlite with and without auxin treatment (Seradix 1 or Seradix 2: 3-indol-butyric-acid). The effect of dipping in a fungicide (Rovral) was also tested. With the best treatment, control without auxin and fungicide, as much as 66% of the cuttings rooted. Both dipping in Seradix and in the fungicide reduced rooting of the cuttings. To test the seasonal variations in rooting of lingonberry cuttings, terminal cuttings were harvested regularly every month in more than one year. The results indicate that a relatively short cold period is needed to induce bud break and shoot growth. Cuttings harvested during spring and summer rooted poorly compared to cuttings harvested in late autumn and during winter. The best rooting was obtained using cuttings harvested in September and November.