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.
2001
Forfattere
Tove M. ØstensvikSammendrag
Det er ikke registrert sammendrag
Forfattere
Halvor SolheimSammendrag
Det er ikke registrert sammendrag
Forfattere
Arne SæbøSammendrag
Myr finnes først og fremst i deler av verden hvor det er korte og kjølige somrer. Når vannet stenger ute oksygenet, vil nedbrytningsprosessene bremses og organisk materiale hoper seg opp. En myr er et slikt område hvor overflaten er dekket av plantevekst og et lag av dødt organisk materiale har nådd minst 30 cm tykkelse. Torvlaget øker i gjennomsnitt med 1 mm per år. Dvs 1000 år per meter torvlag. I Norge er 6-7 % av lavlandet dekket av myr eller annen våtmark. Det er dobbelt så mye som vårt dyrka areal.
Forfattere
Stein Harald HjeltnesSammendrag
Nashi kan prøvast i norske småhagar, men må tynnast godt og gjerne dyrkast i espalier for å få god utvikling på fruktene. Det er få sortar som når fullgod utvikling. Dei beste som er prøvde på Njøs er den bronsefarga Chojuro og den gule Shinseiki
Forfattere
Helle Huseby Chris Helen Kvendseth Ayse M. Bulak HageliaSammendrag
Å sikre forbrukerne trygg mat på det nasjonale markedet har lenge vært en del av landbruks- og helsepolitikken i EU, USA, Canada, Australia og New Zealand. Det har vært tradisjon for at importerte produkter skal oppfylle landets trygghetskrav på lik linje med landets egne produkter. Regelverket for hvordan man kontrollerer og gjennomfører tiltak for å sikre at kravene opprettholdes, berører dermed internasjonal handel med landbruksprodukter. De nasjonale tiltakene vedrørende mattrygghet skal ikke virke handelshindrende i forhold til reglementet i Verdens Handelsorganisasjon (WTO). Dette har alle de fem aktørene forpliktet seg til som medlemmer av WTO. De siste årene har oppmerksomheten blitt stadig større omkring liberalisering av internasjonal matvarehandel og hensynet til trygg mat. Etter hvert som tollsatser fortsetter å bli bygd ned, vil trolig tekniske handelshindringer og ulike oppfatninger omkring standarder for matvarer stadig oftere virke som handelsbegrensninger. Legitimering av særegne, nasjonale reguleringer og standarder kan være en måte å hindre eller begrense import av bestemte matvarer til et land. De senere årene har det derfor blitt viktigere både å dokumentere på vitenskapelig grunnlag behovet for å innføre handelsbegrensede tiltak, og å rette fokus mot forbrukernes behov. Vitenskapelige resultater har således blitt viktige for å dokumentere og legitimere politiske tiltak. Trygg mat og utformingen av nasjonale og internasjonale standarder har utviklet seg til å bli politikk på høyt nivå. Rapporten viser at det er et skille i oppbygningen av systemet for trygg mat mellom EU på den ene siden og USA og Canada på den andre, når det gjelder hvorvidt regulerende organer på matområdet har beslutningsmyndighet. Mens ansvaret for trygg mat i USA og Canada er samlet i et nasjonalt organ, har ikke EU klart å samle beslutningsmyndigheten. Resultatet er at det fortsatt er opp til det enkelte land i EU å ta seg av lovgivning og håndheving av regelverket på matvareområdet. Australia og New Zealand har et felles system for matvarestandarder som omfatter et eget organ med beslutningsmyndighet, og i New Zealand jobbes det nå med å få en samlet enhet som har ansvar for både risikovurdering og risikoforvaltning på matområdet. Dette at det går et skille særlig mellom USA og EU, går igjen på de fleste områdene vi har omtalt i denne rapporten. En ser det ikke minst i forhold til hva slags prinsipper som skal ligge til grunn for reguleringer innen matregimet. […]
Forfattere
Ingeborg KlingenSammendrag
In a series of studies (Papers I-IV), insect pathogenic fungi from Norway were collected and mapped to evaluate their importance as natural control factors and their potential as microbial control agents against pest insects in Brassica vegetables. An overview of known pathogens of arthropods in Norway is also provided (Paper V).By quantifying the seasonal infection levels of Entomophthora muscae and Strongwellsea castrans in a population of adult Delia radicum and Delia floralis it was revealed that S. castrans and particularly E. muscae cause high levels of mortality. Conservation and enhancement of these fungi have a potential in the control of the flies. Traps modified during the study and used to collect live adults of D. radicum and D. floralis were highly effective and selective and might be used to spread insect pathogens to control the flies.In a survey conducted in northern Norway to isolate insect pathogenic fungi from soil, more insect pathogenic fungi were found in arable fields of organically farmed soil compared to arable fields of conventionally farmed soil. Tolypocladium cylindrosporum was found more frequently when using D. floralis larvae as the bait insect than when using Galleria mellonella.In vitro studies show that 2"phenylethyl isothiocyanate inhibits the growth of both Metarhizium anisopliae and T. cylindrosporum. The effect was more pronounced for T. cylindrosporum. M. anisopliae treated G. mellonella larvae exposed to grated rutabaga resulted in lower infection by M. anisopliae. The effect of plants in the Brassicaceae was also studied in a fungi/plant/soil experiment, but roots of Beta vulgaris and Eruca vesicaria sativa do not seem to have a negative effect on the M. anisopliae and T. cylindrosporum isolates applied to the soil at the bases of the plants. Results obtained on the virulence of Norwegian hyphomycetous isolates to immature stages of D. radicum and D. floralis did not result in a selection of an isolate for further development. Promising results were, however, obtained for Norwegian Beauveria bassiana isolates tested against second instar larvae of Mamestra brassica resulting in mortality up to 70%. Several isolates should be further evaluated as potential microbial control agents
Sammendrag
The coffee leaf miner Leucoptera coffeella (Lepidoptera: Lyonetiidae) is one of the most important coffee pests in Lathin America. Larvae of L. coffeella were collected at 10 different locations in a coffee growing region in Nicaragua to study the natural occurrence of insect pathogenic hyphomycetous fungi. The study reveals that Beauveria bassiana (Deuteromycotina: Hyphomycetes) might be a natural mortality factor for L. coffeella larvae, and a B. bassiana infection level up to 22.1 % was observed. To our knowledge, this is the first study estimating the B. bassiana infection level in L. coffeella, and also one of the first reports on B. bassiana associated with this insect. Significant and positive correlations with B. bassiana infection level in L. coffeella larvae were observed for factors related to high L. coffeella densities, and the coffee variety "Catrenic" showed a significant higher L. coffeella density as well as a higher B. bassiana infection level than the other coffee varieties. A tendency towards higher B. bassiana infection level with increasing shading was also observed. Copper was applied as a fungicide at some of the locations, but did not seem to negatively affect the B. bassiana infection level as much as other fungicides. In this study coffee leaves were also examined for endophytic B. bassiana, but no such association was found.
Forfattere
Rolf D. Vogt E.T. Gjessing Dag Olav Andersen Nicholas Clarke T.C. Gadmar K. Bishop U.S. Lundström Michael StarrSammendrag
In the Total Organic Carbon (TOC) intercalibration sub-project a set of 10 synthetic and natural samples as well as non-labile reverse osmosis isolates were sent to 25 laboratories for the analysis of TOC and dissolved Organic Carbon (DOC).The outcome of the statistical treatment of the results from this intercalibration and the information regarding the participants instruments and standard operational procedures is that:Synthetic samples provide apparent better precision than natural samples. This fact, together with the good experience from the use of non-labile Reverse Osmosis (RO) and freeze dried isolates of dissolved organic carbon (DOM) in the intercalibration, lead us to recommend the use of RO isolates as material for the preparation of house standards and for determination of methods merits.The intra laboratory precision (relative standard deviation) varied from 5 to 16%.The fractionation of the DOC by 0.45um membrane filtering causes in some cases a contamination of carbon to the sample.A specific construction in a brand of the TOC analysers give poor results in samples with high TOC concentrations and that are of refractory material. The five selected sampling sites have proven, on the basis of their soil and water chemistry, to be well suited for studying the effect of climate and S-deposition on the characteristics of DOM. 163 water samples from two seasons (fall and spring) and 20 soil samples are collected and analysed.Most water samples are determined for all major charge contributing species, DOM fractions, and several other parameters. The DOM in the surface waters have been isolated both using reverse osmosis and hydrophobic resin (XAD8). The original surface water, reconstructed water by RO isolates as well as the XAD8 fractionated DOM have been characterized by a number of methods ranging from optical properties to pH and metal titration.The RO isolates have been provided to 14 scientific research groups in Europe and North America that are in the process of using their analytical technique to characterize the DOM.The soils have been determined for key explanatory variables as pH, cation exchange capacity and C/N ratio. The main findings from the characterisation of DOM is that:Generally the hydrophobic acid fraction (HPO-A) was the main DOM fractions in all water compartments and sites.Seasonal variation in the DOM fractionation is found to be greater than the variation between the sites and water compartments. The DOM fractionation is therefore not a fingerprint of the site.According to a batch titration experiment the aluminium complexing ability of the HPO-A and hydrophilics (HPI) DOM fractions (fractionated using only the XAD8 resin) was indistinguishable.The HPI fraction has generally a higher site density of weak acids (WA).The reverse osmosis (RO) isolates represent the total DOM in the original sample.NMR spectres of the RO isolates show that the main difference between the sites lie in the amounts of carbohydrates and aromatic compounds.The RO isolates produce reconstructed water with DOM that have similar optical properties.PCA analysis suggest that as the S-deposition is decreasing we should expect relatively more hydrophobic character of the DOM.The spring sample from Svartberget differs from the rest of the samples in that there was a small rainstorm causing a hydrologic episode during the sampling. This led to the lowest pH, highest TOC and organic charge (A-) among the surface water samples. In terms of DOM characteristics this temporal variation in flow regime led to the highest HPO-N DOM fractions, lowest intensity of the NMR spectre and low ash content and lower density of WA then expected. This expresses the importance of temporal variation during hydrologic episodes.
Forfattere
Rolf D. Vogt K. Bishop Nicholas Clarke T.C. Gadmar E.T. Gjessing Jan Mulder Michael Starr Dag Olav AndersenSammendrag
The main tasks of the NOMiNiC project (Natural Organic Matter in the Nordic countries; see http://www.kjemi.uio.no/envir/nominic/) is to study the physiochemical characteristics of dissolved organic matter (DOM) and provide reverse osmosis (RO) spring and fall isolates of surface water natural organic matter (NOM) from 5 Nordic forested sites that differ mainly in atmospheric S-loading and climate. Hydrophobic and hydrophilic fractions are hypothesized to be more easily defined and have distinct different chemical characteristics than the total sample. A XAD-8 fractionation may then be used as a simple proxy for the physico-chemical properties of NOM. Both XAD-8 fractions and the total DOM sample have been base and metal titrated. Enhanced understanding of the significance of the numerous operationally defined parameters describing NOM will be achieved through a common multi-dimensional characterisation of the same set of isolates, that span a large spectre of the variation found in DOM. 7 institutes are already collaborating in characterizing the RO isolates using a large range of techniques and new participants are invited. In this presentation the 5 sampling sites are described and some results of the characterisation of the RO isolates are presented.
Sammendrag
Det er ikke registrert sammendrag