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.
2008
Forfattere
Sonja KlemsdalSammendrag
The detection and quantification of plant pathogens in soil can be used to predict the risk to develop disease in the crop. Knowledge of the presence of such pathogens can also be used to plan control strategies for plant disease. The detection of carrot pathogens will be used as and illustrating example. Quality of carrots is influenced by several pathogens. In Norway the carrots are usually harvested in October, and while some carrots are used for immediate consumption, most carrots are stored shorter or longer periods in cold storage. During this storage there may be up to 70% loss due to carrot-rot caused by fungal diseases. The most important of these diseases are liquorice rot caused by the fungus Mycocentrospora acerina and crater rot caused by Fibularhizoctonia carotae. A standard PCR-based assay has been developed that enables us to detect the pathogens in the soil attached to the carrots at harvest. The results from this assay can be used to decide whether the harvested carrots can be stored or rather should be consumed immediately. Another disease, cavity spot, is worldwide considered to be one of the most economically important diseases of carrot. Multiple Pythium species are the cause of cavity spot and the importance of each species have been found to differ from one country to another. Five species of Pythium are the most important in causing cavity spot in Norway: P. violae, P. sulcatum, P. sylvaticum, P. intermedium and what is believed to be a new species, given the preliminary name P. "vipa". We have established standard PCR assays for the detection of all these five Pythium species in soil. These diagnostic assays have also been further developed to allow quantitative detection of these same pathogens by real-time TaqMan PCR. Such a test can potentially be used to analyze fields in order to avoid cropping carrots where the corresponding pathogens are found and the consequent risk of developing cavity spot is high. Another potential benefit for such a test might be to use the test result from a growing field of carrots to predict the need to spray this field with pesticides. The general experience is that it is difficult to extract "good" DNA from soil samples, and inhibition of the PCR reaction is often observed. DNA extraction protocols often need to be optimized to reduce the amount of compounds that otherwise would inhibit PCR, e.g. humic acid, as much as possible. Additional purification steps, dilution of the DNA samples and an adjusted mastermix might reduce the problems. Strategies to improve the PCR-based detection of plant pathogens in soil will be discussed.
Forfattere
Arvid Steen Turid Strøm Aksel BernhoftSammendrag
Background Selenium is part of the antioxidant defence system in animals and humans. The available selenium concentration in soil is low in many regions of the world. The purpose of this study was to evaluate the effect of organic versus inorganic selenium supplementation on selenium status of ewes, their lambs, and slaughter lambs. Methods Ewes on four organic farms were allocated five or six to 18 pens. The ewes were given either 20 mg/kg inorganic selenium as sodium selenite or organic selenium as selenized nonviable yeast supplementation for the two last months of pregnancy. Stipulated selenium concentrations in the rations were below 0.40 mg/kg dry matter. In addition 20 male lambs were given supplements from November until they were slaughtered in March. Silage, hay, concentrates, and individual ewe blood samples were taken before and after the mineral supplementation period, and blood samples were taken from the newborn lambs. Blood samples from ewes and lambs in the same pens were pooled. Muscle samples were taken from slaughter lambs in March. Selenium concentrations were determined by atomic absorption spectrometry with a hydride generator system. In the ANOVA model, selenium concentration was the continuous response variable, and selenium source and farm were the nominal effect variables. Two-sample t-test was used to compare selenium concentrations in muscle samples from the slaughtered lambs that received either organic or inorganic selenium supplements. Results In all ewe pens the whole blood selenium concentrations increased during the experimental period. In addition, ewe pens that received organic selenium had significantly higher whole blood selenium concentrations (mean 0.28 "g/g) than ewe pens that received inorganic selenium (mean 0.24 "g/g). Most prominent, however, was the difference in their lambs; whole blood mean selenium concentration in lambs from mothers that received organic selenium (mean 0.27 "g/g) was 30% higher than in lambs from mothers that received inorganic selenium (mean 0.21 "g/g). Slaughter lambs that received organic selenium had 50% higher meat selenium concentrations (mean 0.12 mg/kg wet weight) than lambs that received inorganic selenium (mean 0.08 mg/kg wet weight). Conclusion Organic selenium supplementation gave higher selenium concentration in ewe and newborn lamb blood and slaughter lamb meat than inorganic selenium supplementation.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Veikanter langs dyrka mark er ofte svært næringsrike. En del gjødsel vil alltid havne i kanten, enten på grunn av unøyaktig spredning eller ved tilsig og avrenning fra det dyrka arealet. Planteartene som vokser i slike veikanter er ofte problematiske ugras, slik som hundekjeks. Forsøk med slåttetiltak som kan redusere innslaget av hundekjeks og andre problematiske arter i næringsrike veikanter har blitt gjennomført siden 2004 på Fosen i Sør-Trøndelag. Prosjektet er finansiert av Statens vegvesen og flere kommuner på Fosen. Prosjektet gjennomføres i et samarbeid mellom Fosen Forsøksring og Bioforsk Midt-Norge og avsluttes i 2009. Prosjektet "Slått av næringsrik veikant" ble starta opp i 2004.
Sammendrag
Rapporten beskriver bevaringsmål og metodikk for overvåkning av restaurerings og skjøtselseffekter i Rinnleiret naturreservat, Levanger kommune i Nord-Trøndelag. Rapporten gir også foreløpig status og resultater av overvåkningen.
Forfattere
Celine Rebours Jim Treasurer Richard Fitzgerald Julie Maguire Nina Zhuravleva Oddvar OttesenSammendrag
Biological control of sea lice with wrasse is considered an alternative to medicines and can form part of an integrated sea lice management plan (Mordue and Pike, 2002). While wrasse have been used previously in sea lice control there have been reservations about fishing the wrasse from wild stocks with possible erosion of local stocks and changes in population structure (Sayer, Gibson and Atkinson, 1996; Varian, Deady and Fives, 1996). An EU Northern Periphery Project entitled "Ecofish" has been established to examine the rearing of ballan wrasse Labrus bergylta and the application of this species in sea lice control. This species has been shown to be a successful cleaner of sea lice in preliminary trials and may be more suitable than smaller wrasse with larger second production year salmon.
Forfattere
Ellen Johanne Svalheim Frode ØdegaardSammendrag
Det er ikke registrert sammendrag
Forfattere
Celine Rebours Åsbjørn Karlsen Oddvar H. Ottessen Jim Treasurer Julie Maguire R. Fitzgerald N. ZhuravlevaSammendrag
An EU Northern Periphery Project entitled "Ecofish" has been established to examine the rearing of ballan wrasse, Labrus bergylta and the application of this species in sea lice control. The rapid expansion of finfish farming in Northern Europe has focussed attention on problems caused by a variety of pest organisms such as sea lice which sometimes occur at high densities in coastal waters. This project provide the European marine finfish aquaculture industry with a practical solution to control lice in an environmentally friendly way by using ballan wrasse (a lice eating fish) as a supplement to control lice in sea cages. Until now the R&D activities on ballan wrasse have been local and limited to a few institutions, mainly, in Norway. In the present project, a broad partnership in the Northern periphery area, in a unique collaboration between governmental institutions, public R&D institutions and the industry in Norway, UK and Ireland, are developing methods for production and use of cleaner fish in finfish farming. This is based on substantive interest from fish farmers in Shetland, Scotland, Ireland and Norway in the use of wrasse and whether this can be reared for use as cleaner fish on fish farms. The collective expertise provide a unique opportunity to address the sustainability (environmental and economic) of aquaculture, enabling us to challenge a range of issues in a unified manner that would be difficult or impossible by individual countries acting alone. In this way fragmentation of effort across the Northern Periphery are reduced and a more co-ordinated approach to research at an international level are engendered.
Sammendrag
Nokre planter er det rett og slett forbod mot å planta, så som pile- og bulkemispel, på grunn av pærebrann. Eit anna døme er ask, der det no er restriksjonar på flytting av planter til smittefrie sonar på grunn av askeskotsjuke. Dessutan er det mange planter som er så utsette for sjukdom at ein bør unngå dei på grunn av redusert prydverdi.
Forfattere
Nina TrandemSammendrag
Gjennomgang av skadedyrmiddel-situasjonen for norske bærdyrkere. Nærmere om norske forsøk med kjemisk og alternativ bekjempelse av fem utvalgte skadedyr de siste årene (bringebærbille, jordbærsnutebille, bringebærbladmidd, stikkelbærbladveps, veksthusspinnmidd)