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.
2008
Forfattere
Kirsten TørresenSammendrag
Foreløpige resultater fra feltforsøk og labforsøk for å studere spiring og frøhvile til vårrybs ble presentert.
Sammendrag
De viktigste flerårige ugras i åpen åkerkulturer i Finland, Sverige, Danmark og Norge ble presentert.
Sammendrag
Foredrag om nyere prosjekter på flerårig vandrende ugras, hovedsakelig kveke, åkertistel og åkerdylle.
Forfattere
Kirsten TørresenSammendrag
Presentasjon av prosjektet REDUCE (Reduced pesticide loads and risks in cropping systems). Noen foreløpige resultater fra jordarbeidng og ugrassprøyting i korn, fungicidsprøyting i potet, samt på skjebne til glyfosat i jord ble presentert.
Forfattere
Paal KrokeneSammendrag
Combined bark beetle-fungus attacks are a key factor in conifer ecosystems in the Northern Hemisphere, where they regularly cause massive tree mortality. Central to the success of the bark beetle-fungus complex is the fact that bark beetles are among the few insects that are capable of breaching the potent anatomical and chemical defenses of healthy tree stems.....
Forfattere
Paal KrokeneSammendrag
I British Columbia, Canada er de midt oppe i tidenes største barkbilleutbrudd. Til nå er om lag 135.000 km2 furuskog angrepet, og volumet drepte trær utgjør flere hundre millioner kubikkmeter. Hvis angrepet fortsetter å vokse med samme fart som det har utviklet seg de siste årene vil halvparten av det hogstmodne arealet av kontortafuru i British Columbia være drept innen utgangen av 2008, og innen utgangen av 2013 vil 80 prosent være borte. Billene har i løpet av de siste årene også spredt seg nordover og østover i Canada, og truer nå store furuområder som aldri tidligere har vært utsatt for angrep. Kombinasjonen av et gunstigere klima og en kraftig økning i mattilgangen har skapt nærmest ideelle forhold for barkbillene i Canada, og er årsaken til at det pågående utbruddet er mer omfattende enn noen tidligere utbrudd. Utbruddets enorme geografiske omfang og den høye tredødeligheten gjør at angrepet endrer hele økosystemer, og de økologiske og økonomiske ettervirkningene av angrepet vil være merkbare i flere tiår fremover.
Sammendrag
Tree-killing bark beetles conquer healthy trees by means of pheromone mediated mass-attacks. The initial attackers select trees through a process of random landing and processing of tactile and short-range chemical stimuli. Inside acceptable hosts they produce aggregation pheromones that attract additional attackers. In a recent field experiment we induced defense responses in 60-year-old Norway spruce trees and monitored colonization by the spruce bark beetle Ips typographus. Induced stem sections had significantly less beetle colonization than control sections, with shorter parental galleries and fewer eggs deposited. In addition, fewer beetles were attracted to beetles tunnelling in induced bark. This reduced ability to attract conspecifics suggests that induced host defenses interfere with beetle pheromone production or emission. The mechanisms responsible for this are unknown, but may involve emission of volatile terpenes such as (E)-b-farnesene and linalool, which have been shown to increase up to 100-fold in induced Norway spruce trees. These compounds have been reported to attract natural enemies of herbivores or repel herbivores directly in other conifer-insect interactions.
Sammendrag
Seed production in Norway spruce (Picea abies) seed orchards may be severely reduced by insects attacking cones and seeds. Insects in several orders and genera are responsible for the damage, and at present there are no effective and environmentally acceptable control options. Studies in Sweden have shown promising results with spraying Bt (Bacillus thuringiensis var. kurstaki x aizawai) against species of Lepidoptera, but for other pests other control methods must be developed....
Forfattere
Ricardo Holgado Anette Stryken Christer Magnusson Irene Rasmussen Kari-Ann Strandenæs Bonsak HammeraasSammendrag
A survey was undertaken to investigate the occurrence of plant parasitic nematodes in the municipality of Lier located in southern Norway. A wide variety of vegetables crops are grown in this area. Soils in Lier are mostly sandy loam, and irrigation is practiced when necessary during the growing season. There is little information on the occurrence on plant parasitic nematodes in vegetables; particularly in areas where farmers have specialized in intensive production, and often grow two to three cultures of vegetables during the growing season. In the year prior to this investigation several crops had been observed with symptoms of attack by plant parasitic nematodes. The aim of this survey was to identify the species responsible for the damage. The emphasis was placed on genera of known economic importance. During the end of the growing season plants showing poor growth or symptoms of nematode damage and plants with healthy appearance were sampled. A total of 74 root samples were collected and assessed for galls and 37 soil samples were collected from the rhizospheres. In the study samples were collected from 7 producers. Five samples were taken from cauliflower (Brassica oleraceae var. botrytis), 4 from broccoli (Brassica oleraceae var. italica), 8 from pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis), 8 from lettuce (Lactuca sativa) and 1 from celery (Apium graveolens). Soil sampling included 11 samples from areas with fallow, ploughed and rotocultivated land. Root knot nematodes were not recorded in the root samples. In soil samples economically important nematode genera were recorded. Tylenchorhynchus sp. (72.9 % of samples), was the most frequently encountered genus, followed by the species Heterodera cruciferae and other Heterodera spp. (67.5 %), Pratylenchus spp. (54 %), Paratylenchus spp. (29,7 %), and Helicotylenchus spp. (8.1 %). In addition to cyst detections Heterodera juveniles were found in 32.4 % of samples. In all the samples from Pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis) Heterodera cruciferae was recorded, symptoms of nematode damage was also observed in the field. The results of the survey will help in planning future research as well as in developing effective nematode management strategies suitable for vegetable producer particularly in this area. The authors are thankful to the FMLA in Buskerud County for economical support.
Forfattere
Ricardo Holgado Anette Stryken Christer Magnusson Irene Rasmussen Kari-Ann Strandenæs Bonsak HammeraasSammendrag
A survey was undertaken to investigate the occurrence of plant parasitic nematodes in the municipality of Lier located in southern Norway. A wide variety of vegetables crops are grown in this area. Soils in Lier are mostly sandy loam, and irrigation is practiced when necessary during the growing season. There is little information on the occurrence on plant parasitic nematodes in vegetables; particularly in areas where farmers have specialized in intensive production, and often grow two to three cultures of vegetables during the growing season. In the year prior to this investigation several crops had been observed with symptoms of attack by plant parasitic nematodes. The aim of this survey was to identify the species responsible for the damage. The emphasis was placed on genera of known economic importance. During the end of the growing season plants showing poor growth or symptoms of nematode damage and plants with healthy appearance were sampled. A total of 74 root samples were collected and assessed for galls and 37 soil samples were collected from the rhizospheres. In the study samples were collected from 7 producers. Five samples were taken from cauliflower (Brassica oleraceae var. botrytis), 4 from broccoli (Brassica oleraceae var. italica), 8 from pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis), 8 from lettuce (Lactuca sativa) and 1 from celery (Apium graveolens). Soil sampling included 11 samples from areas with fallow, ploughed and rotocultivated land. Root knot nematodes were not recorded in the root samples. In soil samples economically important nematode genera were recorded. Tylenchorhynchus sp. (72.9 % of samples), was the most frequently encountered genus, followed by the species Heterodera cruciferae and other Heterodera spp. (67.5 %), Pratylenchus spp. (54 %), Paratylenchus spp. (29,7 %), and Helicotylenchus spp. (8.1 %). In addition to cyst detections Heterodera juveniles were found in 32.4 % of samples. In all the samples from Pak-choy Chinese cabbage (Brassica rapa ssp. pekinensis) Heterodera cruciferae was recorded, symptoms of nematode damage was also observed in the field. The results of the survey will help in planning future research as well as in developing effective nematode management strategies suitable for vegetable producer particularly in this area. The authors are thankful to the FMLA in Buskerud County for economical support.