Publikasjoner
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2010
Sammendrag
Bipolaris sorokinana (teleomorph Cochliobolus sativus) is a widespread pathogen of cereals and many grasses. It can infect seeds, roots and leaves, causing seedling blight, common root rot, foot rot and spot blotch. Inoculum of B. sorokiniana may be seed-borne or arise from infected plant debris in the field and from conidia in the soil. Recent years the pathogen has occurred at high frequencies in seed lots of barley in Norway, especially in the cvs Edel and Annabell. A large proportion of the seed lots tested since 2004 were infected and the average infection frequencies were rather high. In order to evaluate the importance of the seed-borne inoculum in barley and to test the effect of seed treatment fungicides against the pathogen, field, greenhouse and laboratory experiments have been carried out with heavily infected barley seed. The infection level was reduced and plant weight, plant height, field emergence and yields were significantly increased by chemical treatment. The best effect was seen with an imazalil+flutriafol compound which increased the yield by approximately 35 % compared to untreated. A healthy untreated seed lot of the same cultivar included in one of the experiments showed approximately the same level of emergence and yield as the best fungicide treatment of a heavily infected seed lot. The investigations demonstrate that the use of healthy seed, or seed treated with an effective fungicide, is important to reduce the yield losses from B. sorokiniana.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Ingerd Skow Hofgaard Heidi Udnes Aamot Sonja Klemsdal Marikka Jestoi Oleif Elen Guro BrodalSammendrag
During the 1980-1990"s Fusarium avenaceum, Fusarium poae, Fusarium tricinctum and Fusarium culmorum were reported as the most frequently isolated Fusarium species in Norwegian cereals. Recent years studies indicate a shift in the relative prevalence of Fusarium species. In a 6-year period from 2004-2009, researchers at Bioforsk collected about 500 grain samples of spring wheat and oats from farmers" fields in South East Norway to study the effect of environmental factors on development of Fusarium spp. and mycotoxins. 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 grain samples were analyzed for Fusarium-mycotoxin content by LC-MS/MS at the Finnish Food Safety Authority. The DNA content of selected Fusarium species (F. graminearum, F. culmorum, F. avenaceum, F. poae, F. langsethiae/F. sporotrichioides) was determined by quantitative PCR (qPCR). Concentrations of deoxynivalenol (DON) above limit of detection (LOD, 50 µg/kg in oats and 45 µg/kg in spring wheat) were registered in more than 90% of the grain samples. Our data shows a trend towards an increased yearly median value of DON and 3-AcDON together with an increased occurrence of F. graminearum (DNA). In general, F. graminearum was detected at much higher levels than F. culmorum (qPCR). Concentrations of HT-2 and T-2 toxin above LOD were mainly registered in oats where more than 70% of the grain samples had a HT-2 concentration exceeding 80µg/kg. Similarly, the DNA content of F. langsethiae/F. sporotrichioides exceeded 0,1 pg per ng plant DNA in more than 70% of the oat samples, whereas this was only true in less than 5% of the spring wheat samples. As F. sporotrichioides is only sporadically found in Norwegian cereals, these results indicate F. langsethiae as the main HT-2/T-2 producer in Norwegian oats. F. avenaceum (DNA) and enniatins were detected in most grain samples indicating F. avenaceum as still being one of the most prevailing Fusarium species in Norwegian cereals. Moniliformin was detected in several of the grain samples, whereas hardly any samples contained nivalenol or diacetoxyscirpenol. Fusarenon-X, neosolaniol, fumonisin B1 and fumonisin B2 were not detected. Bioforsk has during the last 20-30 years been involved in several projects concerning Fusarium spp. and mycotoxins in Norwegian cereals. Prediction models for plant diseases (including Fusarium spp.) in cereals are today operative within the growing season in the Norwegian web-based disease decision support system, VIPS, administrated by Bioforsk http://www.vips-landbruk.no/. In an ongoing project (2010-2014) we focus on the effect of selected cultivation regimes on survival of Fusarium spp. in plant debris and development of mycotoxins in harvested grains of oats and spring wheat. Results will be used as a basis for further development of disease forecasting models, and for the development of guidelines for cultivation practice in Norway.
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
Det er ikke registrert sammendrag
Sammendrag
Foreløpige resultater fra EMTOX-prosjektet
Sammendrag
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Sammendrag
We conclude that these regression models can be used as a basis for the development of prediction models for DON in spring wheat and oats, there are, however, still problems creating general models across geographic areas.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Guro BrodalSammendrag
Det er ikke registrert sammendrag