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.
2011
Forfattere
Berit NordskogSammendrag
Det er ikke registrert sammendrag
Forfattere
Berit Nordskog Trond Rafoss Ragnhild Nærstad Ingerd Skow Hofgaard Halvard Hole Oleif Elen Guro BrodalSammendrag
Forecasting models for prediction of diseases and pests in crop plants are helpful tools in decision support systems for crop management. Correct use of pesticides may result in optimal effect, increased yield and better quality of the crop, while minimizing the environmental strain and costs. In Norway, a range of decision support systems for diseases, pests and weeds are available through the internet service VIPS (www.vips-landbruk.no). The reliability of disease and pest forecasts depends on robust forecasting models and relevant weather data. Although weather data are collected from a network of 80 weather stations located in agricultural production areas in Norway, many farms are remotely located from a weather station. The accuracy of forecasts relies on distance and geographical variation from the farm site to the nearest weather station. Forecasts for pest or diseases can be tailored to fit the local conditions at a farm site by use of weather forecasts and radar measured rainfall. The use of this system will be of particular interest to farms located far from the nearest weather station. Also, locally adapted forecasts for pest or diseases promote a sense of ownership and personal interest in the forecasting systems provided. The Norwegian Meteorological Institute provide weather forecasts on a 4x4 km spatial resolution in rural areas on a 1 hour timescale, while radar measured rainfall has a 1x1 km spatial resolution on a 15 min time scale. These data are currently connected to the existing weather stations to predict warnings ahead of time. The new approach is to adapt these data to individual farm sites. Previous tests have shown that weather prognosis for rainfall is less accurate than weather prognosis for temperature, wind, air humidity and radiation. Estimated rainfall will therefore be based on radar measurements. As part of a pilot project, the use of farm scale forecasts to predict development of plant diseases were tested at 35 farms in the Solør-Odal district in Norway in 2010 and 2011. Preliminary results show that late-blight forecasts produced on a farm scale often differ from forecasts based on data from the nearest weather station, proving the significance of the local approach in farm scale forecasting. Predictions of DON (deoxynivalenol) concentration in oats at harvest based on farm scale weather data, compared to predictions based on weather data from the nearest weather station will also be studied. Future aspects will be to work towards an improved system where farmers throughout Norway can register their farm and automatically have access to a range of pest and disease forecasts based on site specific weather data.
Sammendrag
Downy mildew, caused by Hyaloperonospora parasitica s.l., represents an increasing threat to Norwegian production of cruciferous vegetable crops. Although the pathogen has been present in Norway for over a century, the intensified production regimes of field vegetables has contributed to an increase in disease incidence and severity. The project “Effective and sustainable control strategies for downy mildew in rocket, broccoli and cauliflower” were initiated by vegetable growers and financed by the Norwegian Research Council, “Jordbruksavtalen”, “Fondet” and vegetable growers for the period 2009-2011. As part of the project we have surveyed the presence of downy mildew in cruciferous crops and weeds, tested possible cross inoculation between different cruciferous crops and weeds, and tested how long detached spores can survive in air. The survey of downy mildew incidence in cruciferous crops (mainly rocket, broccoli and cauliflower) and weeds were performed by local extension officers in the Counties Buskerud, Rogaland, Vestfold, østfold, and Hedmark. In addition, 65 growers were asked to survey and report findings in their fields. During the project period downy mildew incidence was mainly observed in wild rocket (Diplotaxis tenuifolia) and broccoli, while a few incidences of downy mildew were reported in swede, oil seed rape and the weed Sheperd’s purse (Capsella bursa-pastoris). The host range of isolates collected in the survey was assessed on a selection of cruciferous species. Seedlings of wild rocket (‘DI902’), cultivated rocket (Eruca sativa), cauliflower (‘Freedom’), broccoli (‘Ironman’), oil seed rape (‘Valo’) and swede (‘Vige’) were inoculated by spraying the cotyledons with a spore suspension. One week after inoculation, the seedlings were incubated over-night at high RH and scored for positive infections by observation of visible sporulation on the cotyledons. Preliminary results show that downy mildew from oil seed rape can infect swede, cauliflower and broccoli. Isolates from broccoli were partly virulent on cauliflower. An isolate from swede were virulent on broccoli, while an isolate from rape were virulent on cauliflower, broccoli and swede. An isolate from Sheperd’s purse was virulent on broccoli. Isolates from wild rocket were not virulent on any of the other plants in the trial. The results indicate a risk of cross infection between different cruciferous species, although also supporting the ongoing discussions on dividing H. parasitica into separate species. The possibility of long distance dispersal of viable spores depends on how long the spores can survive in free air. Spores from freshly sporulating rocket seedlings were transferred to filter paper and exposed to solar radiation or in shade. Preliminary results show that spores were not able to germinate after 6 hours exposure to the sun, while shaded spores were able to survive for 24 hours or more. These results will be included in the development of a forecasting model for downy mildew on cruciferous crops.
Forfattere
Berit NordskogSammendrag
Det er ikke registrert sammendrag
Forfattere
Venche TalgøSammendrag
Sjå Bioforsk Fokus 6(2):126
Forfattere
Venche TalgøSammendrag
Sjå Bioforsk Fokus 6(2):137
Forfattere
Venche TalgøSammendrag
Sjå Bioforsk Fokus 6(2):136
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag