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
Andrea FickeSammendrag
Det er ikke registrert sammendrag
Sammendrag
The leaf blotch disease complex (LBD) frequently reduces yield of wheat in Norway. In visual assessments field symptoms can be difficult to attribute definitively to specific causal agents, and may be caused by any or all of the following three pathogens: Stagonospora nodorum (teleomorph: Phaeosphaeria nodorum) causing Stagonospora nodorum or glume blotch (SNB), Septoria tritici (teleomorph: Mycosphaerella graminicola) causing Septoria tritici or speckled leaf blotch (STB), and Drechslera tritici-repentis (teleomorph: Pyrenophora tritici-repentis) causing tan spot (DTR). There is no broad resistance to all three pathogens in commercially relevant wheat varieties. We analyzed 9 years of historical data on severity of LBD in the field and 36 years of historical data on post-harvest SNB infection of wheat kernels. Overall, correlation between leaf severity and seed severity over years was low (r=0.5). However, during the last 4 years correlations between SNB seed infection and severity of LBD increased (r=0.825). LBD severity varied signficantly with geographic location and increased exponentially on the last 3 leaves betweeen BBCH stage 70 and the last assessment at BBCH stage 89. An improved understanding of environmental and host developmental factors as they affect each member fo the LBD complex in the field will be essential to screening for quantitative and durable resistance to LBD.
Forfattere
Dag-Ragnar BlystadSammendrag
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Forfattere
Dag-Ragnar BlystadSammendrag
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Forfattere
Dag-Ragnar BlystadSammendrag
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Forfattere
Dag-Ragnar Blystad Karen Rae Bone May Bente Brurberg Erling Fløistad Roar Moe Arild Sletten D. L. Davies Carl Jonas Jorge Spetz Sonja KlemsdalSammendrag
We have beendoing research on two phytoplasma diseases relevant for Norwegian plantproduction. Theoccurrence of Apple proliferation phytoplasma in NorwayOurinstitute was made aware of suspicious symptoms in 1996. A few trees of apple‘Summerred’ in Gvarv, Telmark County, had symptoms looking like appleproliferation. This case initiated a survey. The first samples were analyzed inEngland. Later we have done the PCR-diagnosis in our own lab.During asurvey carried out from 1996 to 1998, Apple proliferation was found in 14orchards: 1 experimental orchard inTelemark County, 4 orchards in Vestfold County, 4 orchards in Hordaland Countyand 5 orchards in the County of Sogn og Fjordane.Appleproliferation has later also been found at other locations. From this we canconclude that this quarantine disease is found in almost all importantfruit-producing districts. It is important to follow the situation to stopfurther spread of this disease. All infected trees have been eradicated.Theamount and distribution of Poinsettia branch-inducing phytoplasma in poinsettiaFree-branchingpoinsettias (Euphorbia pulcherrima) were first introduced during the sixties throughthe Norwegian cultivar ‘Annette Hegg’. The identity of the “branching agent”,was proven to be a phytoplasma, termed Poinsettia branch-inducing phytoplasma(PoiBI) (Lee et al. Int. Journal of Syst. Bacteriology 48,1153-1169.1998).Without phytoplasma, poinsettias grow tall, and produce very few branches.We havestudied the relative amount and distribution of PoiBI in poinsettia and howthis relates to branching in different cultivars grown under different lightlevels and temperatures using a quantitative PCR assay (TaqMan). Results fromthis work were presented.
Forfattere
Dag-Ragnar Blystad Randi Knudsen Carl Jonas Jorge Spetz Sissel Haugslien Kari Ørstad Mariano Cambra Tor MuntheSammendrag
In 1998 Plum pox virus (PPV) wasdetected for the first time in Norway. Virus-like symptoms were observed on several trees in a collection ofplum cultivars at Njøs Research Station in the Sogn og Fjordane County in WestNorway. The Norwegian Food SafetyAuthority and the Norwegian Crop Research Institute immediately startedsurveying other variety collections around the country, nuclear stock materialand orchards in all important plum-growing areas. Since 1998 we have surveyed themain part of the commercial plum orchards in Norway. About 75 000 individualtrees have been tested. About 1 % of the trees have been found infected by PPV.Only the PPV-D strain has been found. It is suspected that the main infectionsource was infected plums or apricots imported to Njøs around 1970 or earlier.In most plum orchards in Norway,the spread of PPV by aphids is relatively slow. Therefore, we expect to be ableto eradicate PPV from commercial plum orchards in the near future.The eradication work iscontinuing.
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
Foredrag på fagmøte i Norsk landbruksrådgiving SørØst 10/12-2010
Forfattere
Arne HermansenSammendrag
Det er ikke registrert sammendrag