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
Sammendrag
Kontinuerlig belysning kan redusere angrepet av rosemjøldogg og hemme populasjonsveksten hos veksthusmellus (Trialeurodes vaporariorum) på roser. Men hva skjer med nytteorganismene i et slikt lysregime? Vi har undersøk hvordan kontinuerlig belysning påvirker biologisk bekjempelse av veksthusmellus i snittroser med mellussnyltevepsen Encarsia formosa. Forsøkene ble gjort i vekstrom ved 21oC, 75 % relativ luftfuktighet og 180 mikromol/m2/s lys gitt med en kombinasjon av SONT-lamper og lysstoffrør. Forsøkene bekreftet at populasjonsveksten hos veksthusmellusa ble hemmet av kontinuerlig lys. Det var ingen forskjell i populasjonsveksten ved 20 og 23 timer lys. Encarsia formosa så ikke ut til å bli påvirket av kontinuerlig lys, og ga god kontroll på veksthusmellusa både ved 20, 23 og 24 timer lys.
Forfattere
Gedrime Kusliene Trond Olav Pettersen Tatsiana Espevig Trygve S. Aamlid Anne A. SteensohnSammendrag
High fertilizers rates, especially of nitrogen (N) and phosphorus (P), are commonly used for turfgrass grow-in on sand-based soils. The United States Golf Association recommends preplant applications of up to 1.0 kg P and 0.5 kg N per 100 m2 followed by applications of up to 0.3 kg N/100 m2 every fifth day until plant cover is complete. Such high rates of N and P, given before roots have developed, incur a great risk for nutrient leaching. Irrigation several times per day to keep the seedbed constantly moist also contributes to this leaching potential. iSeed® is a seed coat patented by Yara International ASA and used for grass seed marketed by DLF Trifolium. The coat contains both fast-acting and slow-release fertilizers, in total 10% N and 2% P of coated seed weight. The objective of this research was to determine the effect of iSeed® on turf quality and nitrogen and phosphorus leaching during turfgrass grow-in on two sand-based rootzones. A two-factorial experiment was carried out in the field lysimeter facility at Bioforsk Øst Landvik, South East Norway (58o34"N, 8o52"E) from 22 June to 26 July 2010. The rootzone was maid up of either straight sand, SS, or Green Mix®, GM, (Høst AS, Grimstad Norway), the latter being SS amended with 20% (v/v) mature garden compost. The 2 m2 lysimeter plots were seeded with either iSeed® or uncoated seed of the same seed lot of perennial ryegrass (Lolium perenne L.) ‘Berlioz 1", the sowing rate in both cases corresponding to 20 g/m2 pure seed. Use of uncoated seed was combined with preplant applications of 4 g N (as calcium ammonium nitrate, 27% N) and 0.8 g P (as superphosphate, 8% P) per m2, i.e. the same amount of total nitrogen and phosphorus as in the iSeed® coating. One treatment included additional applications of 5 g N (as calcium nitrate, 15.5% N) and 1.0 g P (as superphosphate, 8% P) on day no. 10 and 21 after sowing. The experiment was irrigated heavily, especially during the first ten days after sowing. Observations were made over the 35 day period. The results revealed significant effects of rootzone composition (SS vs. GM) and/or seed type/additional fertilizer application on turfgrass ground cover, overall impression, colour, surface traction and root development. For all these characters, the GM rootzone showed significant benefits compared with the SS rootzone; however, total nitrogen leaching was 21 % higher and total phosphorus leaching 11 times higher from the GM than from the SS rootzone. Plots seeded with iSeed® usually performed slightly better than plots seeded with uncoated seed, but the visual effects were mostly insignificant and small compared to those of additional fertilizer applications on day no 10 and 21 after sowing. Use of iSeed® reduced nitrate and total nitrogen leaching by approximately 50% during the first 10 days after sowing, but caused no significant reduction during the following 25 days; these effects probably reflect the slow-release properties of 82% of the nitrogen contained in iSeed®. Leaching of phosphorus was not affected by either seed type or additional fertilizer application. Interactions between rootzone and seed type/additional fertilizer applications were mostly not significant. We conclude that iSeed® has the potential to reduce nitrogen leaching during turfgrass establishment on sand-based rootzones. However, as iSeed® does not eliminate the need for additional fertilizer inputs about two weeks after sowing, the environmental benefit seems to be of relatively short duration when growing in perennial ryegrass on athletic fields. The advantages of iSeed® may perhaps be more significant when growing in forage or amenity grasslands over a longer period and with less fertilizer inputs.
Sammendrag
Foreløpige resultater fra EMTOX-prosjektet
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Foredrag om varslingsmodeller for DON i hvete og havre
Forfattere
Svein SkøienSammendrag
Det er ikke registrert sammendrag
Forfattere
Petter D. Jenssen Tore Krogstad Trond Mæhlum Kari H. Skjønsberg Guro Hensel Sven JonassonSammendrag
Det er ikke registrert sammendrag
Forfattere
Trond MæhlumSammendrag
Det er ikke registrert sammendrag
Forfattere
Ricardo Holgado Christer MagnussonSammendrag
In 1955 the potato cyst nematode (PCN) was recorded for the first time in Norway. This detection resulted in extensive surveys and measures were implemented based on the statutory regulation of 1916. The first statutory regulation for PCN was put in power in 1956, and later amended in several occasions. These regulations prohibit the introduction and spread of PCN with soil and plant materials. Early control strategies included the use of chemical fumigants and resistant potato cultivars in infested fields, and surveys detected new infestations which were placed under quarantine regulations. The recognition of G. rostochiensis and G. pallida, their pathotypes enabled a more precise use of resistant cultivars. Commercial chemical fumigants, organophosphates or carbamate nematicides have not been used in Norway since the early 1970s. Today, non-virulent G. rostochiensis is managed by crop rotation, while infestations by G. pallida or virulent G. rostochiensis results in at least 40-years ban for growing potato. Most Norwegian potato cultivars have the resistance genes, Gro-1 (H1) from Solanum tuberosum ssp. andigena. During the preceding decades great emphasis has been placed on documenting freedom from PCN in the production of certified seed potatoes, certified seed potato are used in combination with crop rotations using non-host crops, alternating susceptible and resistant cultivars. These are important control measures, but not easy to implement in Norway due to restricted acreage suitable for long rotations. The safe use of resistant potato cultivars requires a better knowledge on the presence of species and pathotypes in potato fields. In order to improve our information of the occurrence of PCN a new national survey program for the principal potato districts has started. These surveys will complemented by information generated from a new research project dealing with: studies of the virulence of selected PCN populations, decline rates of nematode field population densities and infection potential over time of populations from fields placed under quarantine regulations. studies on the occurrence and pathogenicity of microbial antagonistic parasitic on PCN, and their potential of future management of PCN, the safe use of early potato cultivars as a practical control method, and the potential for using Solanum sisymbriifolium as a trap crop, distinguish the degree of resistance of selected potato varieties available on the Norwegian market, and initial studies of the PCN-Potato-Pathosystem. These expected results of this project possibly will improve the management of PCN, and may alleviate present regulatory restrictions.
Forfattere
Ricardo HolgadoSammendrag
The correct identification to species and pathotype is of crucial importance for the kind management and regulations to be imposed in Norway as G. pallida and G. rostochiensis species are quarantine pests regulated in the national plant health legislation. Identification is in accordance with the EPPO diagnostic protocol. Morphology, Iso electric focousing and molecular methods are used. Today, non-virulent G. rostochiensis is managed by crop rotation, while infestations by G. pallida or virulent G. rostochiensis results in at least 40-years ban for growing potato.