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.
2005
Forfattere
Päivi Rinne Carl Gunnar Fossdal Sissel Torre Heather Danforth Aksel Granhus Gunnhild Søgaard John Einset Harald Kvaalen Øystein Johnsen Chris Van der SchootSammendrag
Det er ikke registrert sammendrag
Forfattere
Paivi L.H. Rinne Carl Gunnar Fossdal Sissel Torre Heather Danforth Aksel Granhus Gunnhild Søgaard John Einset Harald Kvaalen Øystein Johnsen Christiaan van der SchootSammendrag
Det er ikke registrert sammendrag
Forfattere
Tor Håkon SivertsenSammendrag
In spring 2004 it was started a pilot project for determining the lengths of the periods of leaf wetness duration in apple orchards in a small region of commercial fruit growing in the county of Telemark in Southern Norway. In this area it is placed four automated meteorological stations (hourly values). The measurement of precipitation is made by two weather radars in pixel areas of 1x1km. In this pilot project the periods of leaf wetness duration is calculated at the 15 sites ( 15 orchards) using hourly measurements from the automated stations and the two weather radars. The quality of the measurements of precipitation from the weather radars is compared to rain gauge measurements of precipitation at the four automated stations. The concept of quality of meteorological measurements is shortly defined and discussed. Also the possibilities making the quality of the radar measurements better in the future is discussed.
Sammendrag
This study was conducted to explore organic and conventional dairy farmers' perceptions of risk and risk management, and to examine relationships between farm and farmer characteristics, risk perceptions, and strategies. The data originate from a survey of conventional (n=363) and organic (n=162) dairy farmers in Norway. Organic farmers had the least risk averse perceptions. Institutional and production risks were perceived as primary sources of risk, with farm support payments at the top. Compared to their conventional colleagues, organic farmers gave more weight to institutional factors related to their production systems. Conventional farmers were more concerned about costs of purchased inputs and animal welfare policy. Organic and conventional farmers' management responses were more similar than their risk perceptions. Financial measures such as liquidity and costs of production, disease prevention, and insurance were perceived as important ways to handle risk. Even though perceptions were highly farmer-specific, a number of socio-economic variables were found to be related to risk and risk management. The primary role of institutional risks implies that policy makers should be cautious about changing policy capriciously and they should consider the scope for strategic policy initiatives that give farmers some greater confidence about the longer term. Further, researchers should pay more attention to institutional risks. (c) 2004 Elsevier B.V. All rights reserved.
Forfattere
Eldrid Lein MoltebergSammendrag
Det presenteres resultater fra to ulike metoder for å måle skallkvalitet, og fra to ulike vekstavslutningsmetoder. Resultatene viser at fjerning av riset to uker før høsting gir noe bedre skallkvalitet enn om riset får avmodne naturlig helt fram til høsting. Likevel ble de største forskjellene i skallkvalitet funnet mellom sorter og mellom dyrkingssteder. Forskjellen mellom dyrkingssteder ser ut til å henge sammen med lengden på vekstsesongen, andel friskt ris før høsting og tørrstoffinnhold. Sammenligning av flassetest ved hjelp av Torquometer og en definert vaskemetode, viste at Torquometer ga mer reproduserbare resultater som var mindre avhengig av knollform, men begge metodene kan brukes til å skille partier med ulik flassing.
Sammendrag
Fungi cause serious problems in wood utilization, and environmentally benign wood protection is required as an alternative to traditional chemicals. Chitosan has shown promising antimicrobial properties against several microorganisms. In this study, we present the characterization of and antifungal properties of a commercial chitosan formulation developed for impregnation of wood.A broad range of chemical and mycological methods were used to evaluate the uptake, fixation, and antifungal properties of chitosan for wood preservation. The results show that the higher the uptake of chitosan the lower the relative recovery of chitosan in wood after leaching, and the higher the molecular weight of chitosan the higher the recovery.Chitosan with high molecular weight proved to be more efficient against decay fungi than chitosan with low molecular weight. The fungi tested on chitosan-amended nutrient agar medium were totally inhibited at 1% (w/v) concentration.In decay studies using small wood blocks, 4.8% (w/v) chitosan concentration gave the best protection against brown rot fungi.
Sammendrag
This paper describes the use of quantitative real-time PCR for monitoring colonization of birch wood (Betula pubescens) by the white-rot fungus Trametes versicolor in an EN113 decay experiment. The wood samples were harvested after 4, 8, 12, 16 and 20 weeks of incubation.The mass loss was in the range of 440%. Chitin and ergosterol assays were conducted for comparison. Second-order polynomial fits of the mass loss of decayed wood versus chitin, ergosterol and DNA gave correlations (r2) of 0.87, 0.61 and 0.84, respectively. Compared to the other two assays employed, real-time PCR data correlated best with the relative mass loss of decayed samples 48 weeks after inoculation, while the saturation and decline of DNA-based estimates for fungal colonization 1620 weeks after inoculation indicated that the DNA assay is not suited for quantification purposes in the late stages of decay.The impact of conversion factors, extraction efficiency, inhibitory compounds and background levels in relation to the three detection assays used is discussed.
Sammendrag
We investigate ecosystem dynamics by analyzing time series of measured variables. The information content and the complexity of these data are quantifed by methods from information theory.When applied to runoff (stream discharge) from catchments, the information/complexity relation reveals a simple non-trivial property for a large ensemble (more than 1800) of time series. This behaviour is so far not understood in hydrology.Using a multi-agent network receiving input resembling rainfall and producing output, we are able to reproduce the observed behaviour for the first time. The reconstruction is based on the identification and subsequent replacement of general patterns in the input. We thus consider runoff dynamics as the expression of an interactive learning problem of agents in an ecosystem.
Forfattere
Richard Meadow Linda Hjeljord Annette Folkedal SchjøllSammendrag
In order to infect target insects after application to soil or plant surfaces, Metarhizium anisopliae conidia must remain viable in the face of abiotic and biotic factors. As a part of an inveestigation to develop M. anisopliae as an agent against the black wine weevil, we investigated the fungus ability to compete with conidia of fungi commonly isolated from soil and aboveground surfaces of strawberry in Norway. In previous work, we determined the speed of germination of the isolates at various temperatures, and investigated the effects of inoculating various nutrient substances with conidia of the insect pathogens, before or together with conidia of Cladosporium sp., Trichoderma spp., Verticillium sp., Botrytis cinerea, and Gliocladium sp. Results showed that the insect pathogens, germinated as quickly as the other fungi only at temperatures >=25C. Although germination spees of the insect pathogens varied between isolates, none germinated nor grew as quickly at 15 or 20C as did the other fungi. When coinoculated with conidia of the environmental isolates on a range of agar media at 20C, growth of the insect pathogens was strongly inhibited. In contrast, when the insect pathogens were inoculated at a distance from the other fungi, their colonies inhibited mycelical growth of all the other fungi; M. anisopliae isolates produced clear antibiosis zones against Cladosporium sp. and B. cinerea. On nutrient-poor media, or when substrate nutrients were depleted, colonies of the insect pathogens were eventually overgrown by Gliocladium sp. and Trichoderma spp.In an experiment where weevil larvae were exposed to conidia of M. anisopliae and T. atroviride either separately or combined, and incubated in sterile soil at 22C, the Metarhizium appeared to be unhibited in killing the larvae and sporulating. Follow-up experiments are plannes to look at this interaction at different temperatures and when applying the fungi to the soil.
Sammendrag
Artikkelsen oppsummerer noen erfaringer med kompostering under kalde klimatiske forhold i Norge