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
Oskar PuschmannSammendrag
Det er ikke registrert sammendrag
Forfattere
grete h m jørgensenSammendrag
Det er ikke registrert sammendrag
Forfattere
Peder GjerdrumSammendrag
This case study describes reflection, analyses and results obtained from investing in a new saw intake plant with the option to separate pre-sorted logs groups in two sub-sets for increased yield and sawing mini-series of 20-30 logs to maintain high capacity. The new plant was in need of careful trimming and follow-up during a period half a year or more before optimal operation was obtained. Log separation is done based on 3D scaling after debarking. As expected, scaling accuracy was substantially improved. However, scars and damages from the debarker cause some variation in the scaling, and most for 3-dimensional parameters like sweep and taper. Nevertheless, total sawn timber recovery increased by two percent of consumed log volume, equivalent to 2.3 % improvement in the sawmill\"s added value. Sawing two orders simultaneously increased the complexity of planning and sawn timber logistics. Automated sawn timber quality prediction based on observations of barked logs in the 3D scanner has so far not proved successful; one reason for this might be the quality variation within each log. It was concluded that the investment has proven profitable.
Sammendrag
Pieces from the stem, approximately 1.5 m above the trunk base, from two Norway maple (Acer platanoides) trees were collected in March 2010 in a forest in Stavanger, a city on the southwestern coast of Norway. The trees showed dieback symptoms in the crown and had bleeding canker wounds on the stems. Phytophthora plurivora had been isolated from the trunks in 2009. At JKI the wood samples were cut into sections, and a detailed procedure was followed for fixation, dehydration, preinfiltration, infiltration, polymerization, and mounting. The mounted histoblocs with the specimen were removed from the histoforms, and a rotary microtome was used for preparing thin sections which were placed on glass slides for microscope examination. Examination in light microscope revealed that the cells in the vascular system had collapsed. Phytophthora-like hyphal growth was found in and between wooden cells, but not in the bark. Since P. plurivora was isolated from the sample, we may conclude that the hyphae belonged to that pathogen. Also epifluorescence studies were carried out, and we found non-septated hyphae in the rays, further indicating the presence of P. plurivora in the wood tissue.
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Forfattere
Oskar PuschmannSammendrag
Det er ikke registrert sammendrag
Forfattere
Atle Mysterud Leif Egil Loe Erling Meisingset Barbara Zimmermann Arne William Hjeltnes Vebjørn Veiberg Inger Maren Rivrud Anders Skonhoft Jon Olaf Olaussen Oddgeir Andersen Richard Bischof Christophe Bonenfant Øystein Brekkum Rolf Langvatn Hallvard Flatjord Ivar Syrstad Arve Aarhus Vidar HoltheSammendrag
Det er ikke registrert sammendrag
Sammendrag
Colletotrichum acutatum causes black spot in strawberry (Fragaria × ananassa), but it has also been isolated from 30 other cultivated and non-cultivated plant species in Norway, including almost all fruit and berry crops. Bitter rot, which is caused by C. acutatum, is a severe disease in sweet and sour cherry and apple. We have studied the possibility of cross infection of isolates from other hosts and the potential aggressiveness of these isolates on strawberry. Molecular analyses (AFLP) have shown that isolates collected in Norway could be separated into three major phylogenetic groups in which isolates collected from either Prunus spp., Malus domestica or Fragaria × ananassa predominated. Experiments were carried out under laboratory, greenhouse and field conditions, and strawberry fruits, leaves and stolons were inoculated. All experiments showed that isolates originating from the Fragaria group was much more aggressive than those from the other two groups. If detached strawberry fruits were wounded at time of inoculation, isolates from all groups developed black spot, but disease development went much slower for isolates from the Prunus or Malus groups. If not wounded, there was no or hardly any disease development caused by isolates from the latter two groups. On whole plants inoculated in the greenhouse, isolates in the Fragaria group developed an incidence of 27 to 28 % flower and fruit infections compared to 0 to 4 % for isolates from the other two groups. Under field conditions, Fragaria group isolates developed 50 to 70 % more infected fruit than the others at harvest. On stolons, we inoculated by wounding, and differences in aggressiveness between isolates were only minor. On strawberry leaf laminas, we observed that the ability to colonize the leaf surface was much larger for isolates from the Fragaria group compared to those from the other two groups. However, planting healthy strawberry transplants adjacent to infected sweet cherry trees resulted in latent infections of C. acutatum on strawberry leaves (but no visible infections on fruits), indicating that cross infection between host species may occur under field conditions.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Hans Ragnar Norli Geir Kjølberg Knudsen Marco TasinSammendrag
Kairomones intersecting host searching females is an attractive method for species-specific pest control. Apple fruit moth, Argyresthia conjugella, is a major pest of apples in Fennoscandia. The severity of the attacks on apple happens as a response to large scale masting in the moths principal host rowan, Sorbus aucuparia. Co-occurrence of volatile compounds in rowan and apple is suggested to facilitate the forced host shift. The apple fruit moth responds to odour from its principal host with upwind orientation in a wind tunnel. Host responding apple fruit moths have high plasticity to blend ratios suggesting why a specialist insect can locate alternative host during intermast years and damage apples. However, even with all host compounds present, distortions of blend ratios seriously jeopardize upwind orientation in laboratory bioassays. In a combined approach with wind tunnel bioassays and field trapping, we have now identified a seven-component blend which is highly attractive for gravid female apple fruit moths. The new blend is especially attractive in apple crops, showing high odour competition compared to the secondary host. Verification of the blend in monitoring to achieve increased precision of pesticide sprays, establishment of economic damage thresholds and mass trapping is ongoing.