Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2008
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
No abstract has been registered
Authors
Leif Sundheim May Bente Brurberg Trond Hofsvang Christer Magnusson Trond Rafoss Brita Toppe Anne Marte Tronsmo Bjørn ØklandAbstract
Wild oats (A. fatua) is present in 155 out of 431 Norwegian municipalities. It is widely distributed in all municipalities in the main agricultural areas in south-east and central-east Norway, and in the municipalities close to the Trondheim fjord. Otherwise wild oats is present in only a few scattered municipalities not geographically connected to these main areas. Endangered area, not yet infested by A. fatua, is estimated to 228858 ha. This area is spread over the cereal growing part of Norway. The counties of North- and South -Trøndelag have a higher portion of endangered area not yet infested than south and central part of East Norway. The probability of entry of A. fatua from outside the PRA area (Norway) is very low. The probability of spread within Norway is high. In areas with low infestation, like in Trøndelag, the probability of spread is lower than in heavily infested areas. However, in areas with high level of infestation there are few new farms left to be infested. The official wild oats register is a valuable tool in regulations aiming to limit spread. The register also provides a tool to follow up infested farms. The register would be even more useful if inspection for infestation on new farms had been more systematic. Wild oats is no longer devastating even in cereal monocropping, due to cost efficient herbicides. However, in Norway an increasing area is infested with wild oats. The infestation may vary from only a few plants to total coverage of the field. In cereal monocropping chemical treatment with and without hand roguing is the only feasible control methods. Hand roguing alone is expensive and ineffective even on modest infestation. The structural changes in cereal farming result in more farms being managed by entrepreneurs. Field managed by entrepreneurs promotes use of herbicide even on small infestations since this is a cost effective measure to control the weed. Less official control of cereal fields can also be expected. The economical consequences are thus expected to be high. The economical consequences can be even higher in organic farming if the most profitable rotation has to be changed to a less profitable one because of wild oats infestation.
2007
Authors
Christer Magnusson Karl Thunes Hans Nyeggen Hans Overgaard Trond Rafoss Solveig Haukeland May Bente Brurberg K. A. Strandenæs Bjørn Økland Bonsak HammeraasAbstract
The detection in 1999 of the pine wood nematode (PWN), Bursaphelenchus xylophilus, in Portugal triggered survey activities in many European countries. With the assumption that PWN would reach frequency 10 times lower than the native B. mucronatus and the requirement of a 95 % confidence limit suggested 2 995 samples to be required for a safe statement on the absence of PWN from the territory surveyed. Samples were taken from 10 circular areas with 50 km diameter erected from a point of import of risk materials. In the period 2000-2006 3 165 wood samples, 2 880 from Pinus sylvestris, 279 from Picea abies and 6 from unknown wood, were collected from 446 logging sites, in 84 municipalities and 13 counties. Of the total material 85 % of the samples came from cutting wastes, timber or lying trees. Wood showing signs of insect activity (incl. Monochamus) formed 73 % of the total material. Nematodes were recorded in 85 % of the samples. The order Rhabditida was most frequent, followed by the orders Aphelenchida, Tylenchida and Dorylaimida. Rhabditid nematodes were equally frequent in pine and spruce, while Aphelenchida (Aphelenchus, Aphelenchoides, Cryptaphelenchus, Seinura and Bursaphelenchus) and Tylenchida (Filenchus, Lelenchus, Ditylenchus, Deladenus and Nothotylenchus) tended to be more common in pinewood. Aphelenchoides was the most common genus. The genus Bursaphelenchus occurred in 1 % of the samples. B. mucronatus was detected in 0,3 % of the samples and most often in cutting waste of pine. The pine wood nematode (PWN), B. xylophilus, was not detected in this survey. The unexpected low natural occurrence of B. mucronatus indicates that the number of potential niches for PWN also is lower than expected, and hence it will be necessary to continue this surveillance program to reach 10 000 samples. The present zone sites in central and south-eastern Norway will be supplemented with 1-2 zone sites in southwestern region of the country. In the future these zone sites will function as permanent observation areas. Care will also be taken to collect all samples from detached wood with signs of Monochamus activity.
2006
Abstract
Potato mop-top virus (PMTV) is the type member of the genus Pomovirus. PMTV is one of the most damaging potato infecting viruses due to the symptoms induced in the tubers. The symptoms caused by PMTV can be similar to the ones induced by another potato infecting virus, Tobacco rattle virus (TRV). Both viruses are known to generate great economic losses in Norway. Since the beginning of 2005, NCRI has as one of its objectives to enhance research on PMTV and will subsequently initiate studies on TRV as well.
Abstract
We describe the cloning and characterization of a single copy gene from Trichoderma atroviride P1 encoding a novel 30 kDa chitinase, Ech30. Ech30 is a family 18 chitinase showing low sequence similarity to other Trichoderma chitinases. Real-time quantitative RT-PCR studies revealed that expression of the ech30 gene was induced by the presence of Botrytis cinerea in plate confrontation assays, but hardly by chitin in liquid cultures. Studies of Ech30 purified from an Escherichia coli strain overexpressing the ech30 gene devoid of the leader sequence and a predicted intron, showed that the gene encodes an active chitinase, which, as expected for family 18 chitinases, is inhibited by allosamidin.
2004
Authors
Christer Magnusson Hans Overgaard Hans Nyeggen Karl Thunes Solveig Haukeland Bonsak HammeraasAbstract
In this survey of 2002, 600 samples were collected from 83 forest blocks in the counties Akershus, Buskerud, Oppland and Østfold. The sampling activity involved 16 municipallities situated mainly within the three zone sites A, B, and C. Samples from Scots pine (Pinus sylvestris) formed 89%, while samples of Norway spruce (Picea abies) made up 10% of the total sample volume. Timber and forest debris were the most common objects sampled. Sixty-five percent of the pine samples and 81% of the spruce samples showed signs of Monochamus activity. Nematodes were common and occurred in 94% of the samples analysed. Thirteen samples of pinewood were positive for the genus Bursaphelenchus. Bursaphelenchus mucronatus was recorded for the third time in Norway, and was detected in forest debris attacked by Monochamus at Bjørdalen in the municipality of Eidsberg in the county of Østfold. The pine wood nematode Bursaphelenchus xylophilus was not detected in this survey.
Abstract
In this survey of 2003, 600 samples were collected from 96 forest blocks in the counties of Aust-Agder and Vest-Agder in southern Norway. The sampling activity involved 19 municipalities situated mainly within the two zone sites D and E close to Kristiansand and Arendal. Samples from Scots pine (Pinus sylvestris) formed 92%, while samples of Norway spruce (Picea abies) made up 8% of the total sample volume. Timber and forest debris was the most common objects sampled. Ninety-eight percent of the samples, regardless of tree species, showed signs of Monochamus activity. Nematodes were common and occurred in 90% of the samples analysed. Eight samples of pinewood were positive for the genus Bursaphelenchus. This genus did not occur in spruce. Bursaphelenchus mucronatus was detected in 6 samples of forest debris of pine attacked by Monochamus and collected in the county of Aust-Agder. In the municipality of Evje and Hornes B. mucronatus was detected at Skjerkelia and Sutestad. In the municipality of Froland the nematode was found in two samples from Budalsfjellet, and in one sample from Mjålandsvatn. In the municipality of Birkenes one sample from Vågsdalen contained B. mucronatus. This is the fourth report on the occurrence of B. mucronatus in Norway. The pine wood nematode Bursaphelenchus xylophilus was not detected.
Abstract
Dette sammendraget beskriver forekomsten av sharkavirus i Norge, både funnet av sharkavirus på Njøs i 1998 og kartleggingsarbeidet i årene 1998-2003.
2002
Abstract
In 2001, a zone site C, was established as a circular areas with 50 km radius and centred in Greåker close to Sarpsborg in South-eastern Norway. Zone site C is complementary to the similar zone sites A and B established in 2000. From June 2001 to December 2002, 601 wood samples were collected from 66 forest blocks, all situated within the 3 existing zone sites A, B and C. The sampling was carried out in the provinces Akershus, Buskerud, Vestfold and Østfold, but was concentrated to the South-eastern region, where 399 samples were taken from 45 forest blocks in the province of Østfold. Samples from Scots pine (Pinus sylvestris) formed 96% of the collected material, while Norway spruce (Picea abies) was a minor fraction. Lying trees and various kinds of detached wood formed the main part of the objects sampled. The frequency of objects showing signs of attack by wood boring insects was 44%. Some samples were also taken in Porsgrunn in the province of Telemark from a consignment of spruce imported from Russia. Nematodes were often more common in samples from objects with signs of insect activity. In four samples, all from lying pine trees, nematodes belonging to the genus Bursaphelenchus were detected. Bursaphelenchus mucronatus was recorded for the second time in Norway, and occurred in a lying pine tree attacked by Monochamus at Ombudstvedt in the municipality of Våler in the province of Østfold. The pine wood nematode Bursaphelenchus xylophilus was not detected, nor in forests or in 5 samples from spruce imported from Russia
2001
Abstract
Two zone sites, i.e. two circular areas with 50 km radius, were established in southern Norway. The zone sites were centred in Tofte (the location of a major pulp mill) and in Drammen (the site of a major timber yard). From June to October 2000, 66 forest blocks were visited, 65 of which were situated within the zone site areas. Samples were collected from 40 forest blocks, especially from wood attacked by wood boring insects. At 34 forest blocks, trees of Scots pine, Pinus sylvestris, or Norway spruce Picea abies were provided as trap-logs for Monochamus spp. This material will be sampled in the survey of 2001. Some samples were also taken from a wood chip pile and from imported wood material. The total number of wood samples analysed for nematodes were 275. Out of these, 214 samples were collected from forest trees, stumps, timber and logging wastes of P. sylvestris and P. abies. Three samples contained nematodes belonging to the genus Bursaphelenchus, but the Pine Wood Nematode (PWN), B. xylophilus, was not detected. Similarly, this nematode was not detected in the 10 samples of wood chips, or in the 25 samples of imported lumber or in the 26 samples of imported solid wood packing material. In order reach the minimal number of 3000 samples within reasonable time, the number of samples for the next survey season of 2001 needs to be increased drastically. To achieve this, the sampling will continue within the existing zone sites, and be extended into new zone sites to be established in 2001.