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
Forfattere
Dag-Ragnar BlystadSammendrag
Pepinomosaikkvirus har forårsaket mye bekymring i mange land siden det først ble påvist i Nederland og England i 1999. I Norge har vi bare hatt to kjente tilfeller " det første var i 2001, det andre i 2003. Utover dette har ikke pepinomosaikkvirus vært påvist i norske gartnerier. Det har imidlertid tidvis vært mye symptomer som ligner de pepinomosaikkvirus forårsaker på importerte tomatfrukter. De siste årene har det dukket opp mer alvorlige stammer av viruset. For norske dyrkere og veiledere er det fortsatt viktig å være klar over symptomer og smitteveier slik at en kan stoppe et eventuelt utbrudd av dette viruset så raskt som mulig dersom det skulle forekomme nye tilfeller av dette viruset her i landet.
Sammendrag
Denne artikkelen (abstrakt) rapporterer frå funn av Colletotrichum acutatum på knoppar av søt- og surkirsebær og eple.
Sammendrag
Denne artikkelen (abstrakt) tar for seg genetisk variasjon mellom isolat av Monilinia-artar i frukt.
Forfattere
Heidi Udnes Aamot Gunn Mari Strømeng Venche Talgø Jorunn Børve Sonja Klemsdal Arne StensvandSammendrag
Denne artikkelen (abstrakt) skildrar identifikasjon av C. acutatum og genetisk variasjon mellom isolat frå jordbær og andre vertplanter.
Forfattere
Jens G Hansen Arne Hermansen Leontine T Colon David E L Cooke Björn Andersson Bent Nielsen Ulrich Darsow Jozsef Bakonyi Poul Lassen Alison K LeesSammendrag
The Concerted Action on potato late blight `Eucablight" (www.eucablight.org) was launched in 2003 to promote collaboration between researchers across Europe and to collate the previously fragmented data on host resistance to late blight and characterization of its causal pathogen, Phytophthora infestans. Central to the project was the development of standardized protocols, databases and data collection tools with which data from across Europe could be centralized. The ultimate aim was to capitalize on the vast resource of data available in order to allow a pan-European analysis to be conducted. The P. infestans database is currently populated with information relating to over 13,800 isolates from 20 European countries. The host resistance database holds primary disease data and derived statistics from more than 50 field trials assessing mainly foliage blight resistance. The use of seven standard cultivars in these trials facilitated the comparison of resistance information across years and regions. The host database is structured, and made accessible, in such a way that DSS builders can access the model parameters they need to construct locally adapted forecasting systems. In this presentation we describe the data collection and data analyzing tools that have been developed in this project and how they are directly applicable to other host-pathogen systems.
Sammendrag
Light is a common component of forecasting models for downy mildews because its presence is assumed to suppress sporulation. Our objectives were to evaluate the effects of light intensity and quality, temperature, and diurnal periodicity on sporulation of Bremia lactucae, the causal agent of lettuce downy mildew. We found that the suppressive effect of light on sporulation was strongly dependent upon temperature; there was little suppression of sporulation by light at " 10 ºC. At temperatures where light suppressed sporulation, light in the range from 450-500 nm had the most suppressive effect, although a lesser effect of the wavebands from 450-500 nm was detected. At 15 ºC, a diurnal pattern of sporulation was observed independent of light and darkness. In current forecasting models, the time of sunrise and sunset are used to delimit the dark period when leaf wetness and high RH can induce sporulation. In Nordic countries the effects of short nights and extended twilight conditions should be incorporated into forecasting models. Also, since sporulation may be greatly reduced by light at temperatures above 15-20 ºC, this should be used to modify model predictions of sporulation during the time of day when sporulation can occur. The diurnal rhythm could interact with light and temperature to confound the results of controlled environment studies, and may be the controlling factor in timing of sporulation at low temperatures.
Sammendrag
Cavity spot (Pythium spp.), liquorice rot (Mycocentrospora acerina) and crater rot (Fibularhizoctonia carotae) are important carrot diseases. Cavity spot develops during the growing season, while the latter two are post harvest diseases. Five Pythium "species" were identified as agents of cavity spot in Norway; P. intermedium, P. sulcatum, P. sylvaticum, P. violae and P. "vipa" (probably a new species). Based on unique sequence regions in the ITS, PCR primers were designed to identify the five Pythium "species" and the two post harvest pathogens. PCR detection was species-specific with no cross-reaction to other Pythium species or to other fungal isolates from carrots. At different points in the growing season, soil and carrots were sampled from farm fields in Norway. PCR assays allowed detection of pathogens in both soil and carrot tissue. PCR results from samples of soil adhering to roots late in the growing season corresponded well with the incidence of cavity spot and liquorice rot on carrots after 6 months storage. PCR assay data from soil samples taken within 14 days after sowing carrots also predicted cavity spot incidence reasonably well. There was little incidence of crater rot during the experimental period, which did not allow proper evaluation of the test for F. carotae. Commercial testing of carrot soils is now available through the company "Carrotech" and work is in progress to implement quantitative PCR.
Forfattere
Jens G Hansen Bent J Nielsen Lars Bødker Björn Andersson Jonathan Yuen Lars Wiik Arne Hermansen Ragnhild Nærstad Vinh H Le May Bente Brurberg Asko Hannukkala Ari LehtinenSammendrag
Forsøk innen epidemioligi og bekjempelse av potettørråte i det nordiske prosjektet Noprhyt blir presentert
Sammendrag
To avoid problems with seed borne diseases in organic cereal production, seed health testing should be compulsory in certification of organic seed. In general, significantly lower infection frequencies of seed borne diseases are recorded on seedlings than on seed. Thresholds for the amount of seed borne inoculum that can be accepted for organic production are therefore needed. The aim of the work presented is to compare transmission rates of Drechslera on barley and oats under organic and conventional conditions, to be able to decide if existing thresholds used to assess the need of chemical seed treatment, can be applied for acceptance of organic seed lots, or for recommendation of alternative treatments. Field experiments were carried out in 2005 in conventional and organic fields situated close to each other at each of three locations (south/east-Norway, east-Norway and mid-Norway). 10 seed lots of barley and 10 lots of oats, with a range of seed infections (barley: 0-94 % Drechslera teres, average 23,7 %; oats: 0-66 % Drechslera avenae, average 22,0 %) were planted in rows of 100 seeds with 8 replicates in each location/`growing system". Percent emergence and seedlings with primary infections were recorded at BBCH 12-13. In average of the three locations 2,5 % and 2.1 % barley seedlings were infected when grown in conventional and organic fields, respectively. In oats, 2,0 % and 0,8 % infected seedlings were recorded in conventional and organic fields, respectively. Similar experiments will be carried out in 2006 and results from this will also be presented.
Sammendrag
Alternativer til kjemiske beisemidler ble utprøvd mot frøoverført byggbrunflekk(Drechslera teres) og havrebrunflekk (Drechslera avenae) i 2005. Frø med naturlig smitte av patogenene ble beiset med ulike konsentrasjoner av eddik, Inulex (ekstrakt av planten Inula viscosae) samt Terra Biosa (fermenterte urter). Effekten av disse midlene ble sammenlignet med effekten av godkjent kjemisk beisemiddel og med Cedomon (basert på bakterien Pseudomonas chlororaphis) som også er godkjent til bruk i økologisk såvare. Midlene ble testet i felt og analysert på såvarelaboratoriet Kimen. Både Inulex og eddik (25 og 35%) hadde effekt mot byggbrunflekk, mens effekten mot havrebrunflekk var dårligere. Mot byggbrunflekk var effekten av eddik ofte like god som effekten av Cedomon. Begge eddik-konsentrasjoner hadde effekt mot soppen, men høyeste konsentrasjon hadde tendens til å virke hemmende på oppspiring.