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.
2006
Forfattere
Ricardo Holgado Stig Andersson Christer MagnussonSammendrag
Cereal cyst nematodes, Heterodera spp., are known worldwide as parasites of cereals and grasses. Surveys of cereal fields in Norway have revealed that nematodes belonging to the H. avenae complex occur throughout the country, and that H. avenae (the oat cyst nematode) is the most common species, followed by H. filipjevi (the rye cyst nematode). Both species are of economic importance in Scandinavia. H. avenae has been found in two common pathotypes, Ha 11 and Ha 12. Work in Sweden, however, has detected three additional pathotypes, H. avenae "Knislinge", H. avenae "Ringsåsen" and H. avenae "Våxtorp". These pathotypes were found also in the Norwegian surveys. In Sweden H. filipjevi has two pathotypes, "East" and "West". In Norway, only pathotype "West" has been detected so far. Nematode management practices must be based on the knowledge of the relationship between initial nematode density and yield, the population dynamics, and the measures capable of reducing or keeping the population density below the threshold for economic damage. Crop rotation and the use of cultivars with resistance are important measures for controlling cereal cyst nematodes. Several cereal cultivars with resistance to H. avenae are on the market. As to H. filipjevi, resistance may be found in some commercial cultivars, although no intentional breeding for resistance against this nematode species has been attempted. In 2004 and 2005 the majority of the cereal cultivars on the Norwegian market were tested for susceptibility/resistance towards H. avenae pathotype Ha 11, H. avenae pathotype "Våxtorp" and H. filipjevi pathotype "West". Management systems, based on careful nematode identification and good knowledge of appropriate resistant cultivars, are in operation in Norway. Resistant barley is generally recommended when nematode populations are high due to its high tolerance compared to resistant oats. Farmers implementing this program have reported increased cereal yields on the average of 1000 kg /ha. It has been calculated that by implementing this program in full the county of Vestfold could make an economic gain of 800 000 " annually.
Forfattere
Sverre Kobro Geir Kjølberg KnudsenSammendrag
Det hender at det er mark i eplene. Markene er larver av en liten sommerfugl. Den heter rognebærmøll fordi den normalt utvikler seg i bærene på rogn. I enkelte år er det for lite bær på rogna, bare da kan møllet angripe eple.
Forfattere
Øyvind Meland Edvardsen Halvor SolheimSammendrag
Det er ikke registrert sammendrag
Forfattere
Ricardo HolgadoSammendrag
Det er ikke registrert sammendrag
Forfattere
Christer MagnussonSammendrag
Det er ikke registrert sammendrag
Forfattere
Trond RafossSammendrag
Det er ikke registrert sammendrag
Forfattere
Richard MeadowSammendrag
Det er ikke registrert sammendrag
Forfattere
Gilbert Kamgan Nkuekam Jolanda Roux Halvor Solheim Michael J. WingfieldSammendrag
Det er ikke registrert sammendrag
Forfattere
Maria HerreroSammendrag
P.capsici funnet for første gang i agurk i Norge i 2005
Forfattere
Marie Bengtsson Gunnhild Jåstad Geir Kjølberg Knudsen Sverre Kobro Anna-Carin Bäckman Peter WitzgallSammendrag
Plant volatiles mediate host finding in insect herbivores and lead to host fidelity and habitat-specific mating, generating premating reproductive isolation and facilitating sympatric divergence. The apple fruit moth, Argyresthia conjugella Zeller (Lepidoptera: Argyresthiidae), is a particularly suitable species to study the cues and behavioural mechanisms leading to colonization of a new host: it recurrently oviposits on the non-host plant, apple Malus domestica Borkh. (Rosaceae), where the larvae cannot complete their development. The larval host of the apple fruit moth (Lepidoptera, Argyresthiidae), is rowan Sorbus aucuparia L. (Rosaceae). Fruit setting in rowan, however, fluctuates strongly over large areas in Scandinavia. Every 2"4 years, when too few rowanberries are available for egg laying in forests, apple fruit moth females oviposit instead on apple in nearby orchards, but not on other fruits, such as pear or plum. This poses the question of which cues mediate attraction to rowan and apple, and how apple fruit moth discriminates rowan from apple. Chemical analysis and antennal recordings showed that 11 out of 15 rowan volatiles eliciting an antennal response in A. conjugella females co-occur in rowan and apple headspace, in a different proportion. In the field, A. conjugella was attracted to several of these plant volatiles, especially to 2-phenyl ethanol, methyl salicylate, and decanal. Addition of anethole to 2-phenyl ethanol had a strong synergistic effect, the 1 : 1 blend is a powerful attractant for A. conjugella males and females. These results confirm that volatiles common to both plants may account for a host switch in A. conjugella from rowan to apple. Some of the most attractive compounds, including 2-phenyl ethanol, anethole, and decanal, which have been found in several apple cultivars, were not present in the headspace of the apple cultivar, Aroma, which is also susceptible to attack by A. conjugella . This supports the idea that the odour signal from apple is suboptimal for attraction of A. conjugella , but is nonetheless sufficient for attraction, during times when rowan is not available for egg laying.