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.
2010
Forfattere
Christer MagnussonSammendrag
The recent spread of pinewood nematode (PWN) Bursaphelenchus xylophilus in Europe is a concern to Nordic countries. Since PWN may exist in trees free of symptoms its distribution becomes unclear. Commodities like pulpwood, particle wood (PW) and wood packaging material (WPM) could have hidden infections. Pulpwood offers obvious risks of transmission due to a possible presence of both PWN and its vectors (Monochamus spp.). Generally, PW is considered to pose a low theoretical risk due to absence of vectors, and WPM no risk if heat treated. Transmission of PWN from infested wood to trees has been demonstrated, and a recurrent use of PW on sports tracks may during one forest cycle result in transmission. PWN can survive for long periods in wood, and reported limited heat treatment capacities indicate that infested WPM already may circulate within the EU. In the Nordic region, pallet wood is a popular fuel and is stored at summer houses where direct contact with trees could cause transmission. In Nordic locations establishment of PWN is expected to cause damage only in hot summers. Even in a warmer climate the damage at least in a 50 yrs perspective is expected to be small, but costs of nematode control will be very high. In a short perspective effects on Nordic exports are small, but in a longer perspective new outbreaks of pine wilt disease in Europe could change export markets. Key Words: Pinewood nematode, Europe, trade risks, Nordic region
Forfattere
Christer MagnussonSammendrag
The spread of the pinewood nematode (PWN) Bursaphelenchus xylophilus in Europe is a threat to 36 million ha Nordic coniferous forests. In spite of a strict phytosanitary regulation of wood imports, the volumes and an unclear distribution of PWN could result in an introduction into the Nordic region. In the present climate expression of pine wilt disease is expected only in hot summers. Hence, the detection of PWN in the Nordic area is likely to remain unnoticed for a considerable period of time. In Fennoscandia more than 9000 samples have been analyzed from risk areas and risk commodities. The focus often has been on the breeding substrate of the vector insects in the genus Monochamus. A recent study on a simulated introduction in Norway (Økland et al in print) indicates that 14 years may elapse before detection by the present level of 400 samples annually. It was demonstrated that an earlier detection of PWN provided by an annual sample volume of 10 000 samples would still not be sufficient for successful eradication of PWN by 3 km radius clear-cuts. So, large sampling volumes and strict import regulations for PWN are highly important for the Nordic area. Økland, B.O. Skarpaas, M. Schroeder, C. Magnusson, Å. Lindelöw & K. Thunes 2010. Is Eradication of the Pinewood Nematode (Bursaphelenchus xylophilus) Likely? An Evaluation of Current Contingency Plans. Risk Analysis in print Key Words: Pinewood nematode, Nordic area, sampling, eradication, regulation
Forfattere
Christer MagnussonSammendrag
S.radicicola is a parasite of barley and grasses like Poa annua and P.pratensis. The life cycle of a Norwegian population of S.radicicola (Poa-race) is studied in the laboratory by inoculating newly germinated P.annua (cv. Leif) with 140 juveniles from field collected galls and keeping the plants at 25˚C and 16 hrs light period. Juvenile stages are separated based on genital development. The first stage (J1) has 1 cell, while the following stages J2, J3 and J4 has 2, 3 and 4 (or more) cells in their genital primordia. J1 (L = 310-350μm) moults in the egg and J2 (L = 330-400μm) is the hatching stage. Nematodes emigrating from field collected galls were all J3:s (L = 360-430μm), and moulted outside the gall to J4 (L = 210-500μm). The first stage to appear in newly formed galls is large J4 (L=500-870 μm), which moults within 5 days to adult (L=820-1980 μm). Egg-laying starts within 13 days and eggs hatch after 22 days. Juvenile development in eggs starts at 5˚C, and 640 degree days are required for completing one generation corresponding to about 30 days at 25˚C. This means that in Norway S.radicicola may have up to 3 generations per year. The fact that J3 exit the galls and the large J4 is the first stage present in newly formed galls makes us speculate that the induction of gall formation occurs from outside by pre-infective J4, which later infects and develop inside the gall. Key Words: Root gall nematode, Subanguina radicicola, Poa annua, life cycle, Norway
Sammendrag
I "Fusariumprosjektet" ved Bioforsk Plantehelse har vi i løpet av en 4 års periode (2006-2009) samlet inn kornprøver fra partier med norskprodusert havre og vårhvete med tilhørende opplysninger om klima og dyrkningsmessige forhold. Kornprøvene er videre analysert for innhold av 17 ulike mykotoksiner. Ved å sammenstille og analysere data og informasjon om de ulike kornprøvene, har vi kartlagt ulike faktorer som kan ha betydning for utvikling av mykotoksiner i kornet. Dataene er videre brukt for å utvikle varslingsmodeller for Fusarium-mykotoksiner i korn, og for utprøving av ulike hurtigmetoder som er utviklet for å måle innhold av mykotoksiner i korn.
Forfattere
Ingerd Skow Hofgaard Guro Brodal Heidi Udnes Aamot Oleif Elen Marika Jestoi Sonja KlemsdalSammendrag
In a 6-year period from 2004-2009, about 500 grain samples of spring wheat and oats were collected from farmers" fields in South East Norway. In order to study the effect of environmental factors on development of Fusarium spp. and mycotoxins in cereal grains, climate data was collected from the nearest weather station and information on cultivation practice in the respective fields was registered for each grain sample. All samples were analyzed for 18 different Fusarium-mycotoxins by LC-MS/MS at the Finnish Food Safety Authority, and the DNA content of selected Fusarium species (Fusarium graminearum, F. culmorum, F. avenaceum, F. poae, F. langsethiae/F. sporotrichoides) was determined by quantitative PCR.
Sammendrag
The increased occurrence of Fusarium toxins during recent years in Norwegian cereals, especially deoxynivalenol (DON) in spring wheat and DON and T-2/HT-2 toxins in oats (see abstract by Hofgaard et al), is a serious challenge for the cereal industry and farmers. Contamination levels above regulatory or advisory maximum limits have frequently been detected. In Norway, many farmers bring their grain directly to the buyer at harvest, and, in a time and cost perspective, it is not realistic to test all grain lots for mycotoxin content by chemical analysis. In order to reduce the risk of cereal grain lots with unacceptable Fusarium toxin content entering the feed and food chain, a three-step screening strategy has been developed in close cooperation with the cereal industry. 1 Toxin risk (DON, T-2/HT-2) in cereal fields will be predicted by models based on information on climatic conditions and agronomic/cultivation practice (see abstract by Elen et al). 2 Grain from "high-risk" fields will be analysed for mycotoxins by a rapid "on-site" test method (lateral flow tests) before the grain enters the silo/storage/mill. 3 Samples from lots with toxin levels close to the defined maximum limits (based on analyses in step 2) can be forwarded to chemical analyses for precise decision of the mycotoxin concentrations.
Sammendrag
I "Fusariumprosjektet" ved Bioforsk Plantehelse har vi i løpet av en 4 års periode (2006-2009) samlet inn kornprøver fra partier med norskprodusert havre og vårhvete med tilhørende opplysninger om klima og dyrkningsmessige forhold. Kornprøvene er videre analysert for innhold av 17 ulike mykotoksiner. Ved å sammenstille og analysere data og informasjon om de ulike kornprøvene, har vi kartlagt ulike faktorer som kan ha betydning for utvikling av mykotoksiner i kornet. Dataene er videre brukt for å utvikle varslingsmodeller for Fusarium-mykotoksiner i korn, og for utprøving av ulike hurtigmetoder som er utviklet for å måle innhold av mykotoksiner i korn.
Forfattere
Ignace Godonou Trond Hofsvang Ignace Godonou Ghislain T. Tepa YottoSammendrag
Det er ikke registrert sammendrag
Sammendrag
Foredraget gir en oversikt over det vi vet per i dag om hvordan veksthuslyset kan påvirke trips, mellus og de nyttedyrene som brukes i biologisk bekjempelse, og presenterer resultater fra egne forsøk med LED-lamper og ekstreme daglengder i roser. Konklsjon: •Växsthusbelysningen påvärkar beteende och biologi hos skade- och nyttodjur • Effekten av ljuset varierer från art til art. Svårt at generalisera. • Stort behov för kunskap om växsthusbelysningens betydning för biologisk och integrerat bekämpning • Samspel med andra faktorer: T.ex. temperatur, gjödning, vatten och CO2, planteart och sort.
Sammendrag
The leaf blotch complex is one of the most important yield limiting disease on wheat in Norway. It is caused by three pathogens, Septoria tritici ( Mycosphaerella graminicola), Stagonospora nodorum ( Phaeosphaeria nodorum), and Drechslera tritici-repentis (Pyrenophora tritici-repentis). The symptoms of each of the pathogens are similar and easily confused with leaf senescence, making it difficult to assess the true disease severity and thus hampering breeding for leaf blotch resistance. To reduce unnecessary pesticide use and the risk of pesticide resistance developing in the fungal populations, timing of disease control measures are based on forecasting models. The degree of a leaf blotch epidemic is determined by initial inoculums, precipitation, temperature, time, availability of susceptible hosts and the degree of susceptibility. During the last 20 years, the start of the growing season as marked by a soil temperature of 5C, has advanced by 1-1.5 days per year (Rafoss, 2009), indicating an increase in the length of growing seasons. The trend for warmer and wetter growing seasons is predicted to continue in the future. It is of high relevance to the wheat industry to understand the impact of these changes on leaf blotch diseases in the field to optimize disease forecasting and management. We have collected data on leaf blotch severity in the field and weather conditions at different wheat growing areas in Norway over the last 10 years. Based on this data, we do not see a general increase in disease severity over the last decade. However, the data shows that there are local shifts in maximum disease severity; areas that support high disease severity and areas that support very little. Given the amount of initial inoculum and availability of susceptible hosts are comparable between the different wheat growing areas, the local climate per site becomes the determining factor for the epidemic. We studied the effect of relatively small, local differences in precipitation, temperature, and start of growing season on leaf blotch development in the field. The analysis of local shifts in climatic conditions and their relation to disease development allows us to estimate the effect of the changing climate on leaf blotch disease in the future.