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
Currently, very little data exist on the exposure of soil biota to engineered nanoparticles (ENPs), in spite of soils being an important potential sink for ENPs. This is mainly due to difficulties in tracing ENPs in soils where natural nanoparticles are abundant. We used neutron activated ENPs as tracers and examined the exposure (uptake, excretion and internal distribution) of nanoparticles of cobalt (Co NPs 3.9 ± 0.8 nm) and silver (Ag NPs 20.2 ± 2.5 nm) in the earthworm Eisenia fetida, and compared this to soluble cobalt and silver salts. Accumulation patterns were highly different for cobalt and silver. Concentrations of cobalt in worms reached 88% and 69% of the Co ions and Co NPs concentrations in food, respectively, while corresponding values for Ag ions and Ag NPs were 2.3% and 0.4%. Both Ag NPs and Ag ions in earthworms were excreted rapidly, while only 32% of the accumulated Co ions and Co NPs were excreted within 4 months. High accumulation of cobalt was found in blood, and to a lesser extent in the digestive tract. Sequential extraction and centrifugal ultrafiltration provided useful information on metal speciation and bioavailability of Co NPs and Ag NPs.
Sammendrag
Most fungicide applications targeting apple scab aim to control primary infections caused by ascospores and spraying is thereby linked to ascospore availability. We investigated the effect of pre bud break climatic conditions on seasonal patterns of ascospore release. Apple leaves bearing pseudothecia of Venturia inaequalis were overwintered at orchard sites in 8 countries for up to 3 years. Leaf samples were collected 2 to 5 weeks before bud break and again at bud break, air dried, and sent via airmail to Norway. The samples were stored at -18ºC upon arrival until tested. Disks cut from each replicate leaf sample were incubated moist at 20ºC to allow ascospore maturation but prevent discharge. Matured ascospores were induced to discharge twice a week and enumerated until the supply was exhausted. The proportion of ascospores ejected was fitted against degree-day accumulation using logistic regression. The regression intercept (onset maturation), slope (maturation rate), as well as the absolute number of spores counted differed significantly (P< 0.001, P = 0.05, P< 0.001 respectively) among sites and sampling dates. There was a significant interaction between site and sampling date, indicating that climatic conditions prior to bud break differentially impacted the subsequent ascospore availability. Observed differences could perhaps be used to further refine previously described models of ascospore maturity.
Forfattere
Einar Timdal Harald Bratli Reidar Haugan Håkon Holien Tor TønsbergSammendrag
Artikkelen har parallell engelsk og norsk tekst.
Forfattere
Jens Kværner Ole Martin Eklo Marit Almvik Randi Bolli Tore Sveistrup Geir Tveiti Oddvar VigdalSammendrag
Det er ikke registrert sammendrag
Sammendrag
Peatland drainage results in several environmental impacts such as release of greenhouse gas to the atmosphere and leaching of nutrients to watercourses. These hazardous environmental effects can partly be controlled with soil management, and different drainage and remediation practices. Grading is a new method developed for soils with low conductivity suffering from poor drainage, water logging and ice. The soil surface is graded towards the ditch to increase surface runoff and drainage. The present study compares environmental effects of peatland grading compared to traditional intense pipe drainage. Detailed measurements of hydrology, climate, leaching and gas emissions were carried out at adjacent drainage areas with grass cultivation. Additional measurements were made at plots that were abandoned, cultivated with perennial crops, and remained as pristine peatlands. The results show that the leaching of nutrients is highest from pipe drainage. Climate gas emission was considerably higher at all managed sites than from the reference pristine site. Drainage, soil hydrology and soil nutrient status seemed to control gas emissions. The gas emissions were higher than assumed for Norwegian cold conditions. The results confirm observations made on peat soils in other climatic regions. The highest emissions of CO2 was observed when the soil temperature was high and groundwater table low. The N2O emission showed a large variation with no clear pattern. However, at some locations it peaked after a dry period when NO3-N was leached. More CH4 was emitted from the intensively drained site than the graded site, but more CO2 was emitted from the graded site. The difference in leaching and emission properties is partly due to differences in near surface hydrology. At grade sites, a faster runoff response to rainfall occur probably due to shallow throughfall or overland flow which provides better drainage. Also, the graded site was prepared recently, and this can have exposed fresh peat for decay. Therefore the drainage history must be well known in peatland studies as peat change in time due to drainage and cultivation. Abandoned peat field continue to leach greenhouse gases in a same way as cultivated sites.
Sammendrag
The leaf blotch disease complex (LBD) frequently reduces yield of wheat in Norway. In visual assessments field symptoms can be difficult to attribute definitively to specific causal agents, and may be caused by any or all of the following three pathogens: Stagonospora nodorum (teleomorph: Phaeosphaeria nodorum) causing Stagonospora nodorum or glume blotch (SNB), Septoria tritici (teleomorph: Mycosphaerella graminicola) causing Septoria tritici or speckled leaf blotch (STB), and Drechslera tritici-repentis (teleomorph: Pyrenophora tritici-repentis) causing tan spot (DTR). There is no broad resistance to all three pathogens in commercially relevant wheat varieties. We analyzed 9 years of historical data on severity of LBD in the field and 36 years of historical data on post-harvest SNB infection of wheat kernels. Overall, correlation between leaf severity and seed severity over years was low (r=0.5). However, during the last 4 years correlations between SNB seed infection and severity of LBD increased (r=0.825). LBD severity varied signficantly with geographic location and increased exponentially on the last 3 leaves betweeen BBCH stage 70 and the last assessment at BBCH stage 89. An improved understanding of environmental and host developmental factors as they affect each member fo the LBD complex in the field will be essential to screening for quantitative and durable resistance to LBD.
Forfattere
Andrea FickeSammendrag
Det er ikke registrert sammendrag
Sammendrag
Utviklingen av LED-lamper til vekstbelysning er i full gang, og noen gartnere har allerede begynt å prøve ut lamper med en blanding av rødt og blått lys. For å samle praktisk erfaring med hvordan slike lamper kan påvirke skade- og nyttedyr utførte vi et forsøk i to veksthus med rosesortene "Ingrid Alexandra" og "Passion". Daglengden var 20 timer, og temperaturen var innstilt på 18-19oC med lufting på 23,0-23,5oC. Relativ luftfuktighet var innstilt på 79 %. Det var installert 150 W/m2 med SON-T-lamper (600 W) i veksthusene (150 µmol/m2/s i plantebestandet). Over 3 forsøksruter i hvert veksthus ble det i tillegg til SON-T-lampene hengt opp 2 LED-lamper med en blanding av 80 % rødt (620-630 nm) og 20 % blått (400-500 nm) lys (50-60 µmol/m2/s). Over 3 andre forsøksruter var det bare SON-T lamper. Resultatene viste at det ble fanget mer amerikansk blomstertrips på limfeller og i blomstene under LED-lampene, enn der det bare var SON-T-lampter. De voksne mellusene reagert motsatt av amerikansk blomstertrips, dvs. at det stort sett var mest veksthusmellus på limfellene i forsøksrutene med bare SON-T-lamper. Lampetype så ut til å ha liten effekt på rovmidd (Amblyseius swirskii).
Sammendrag
Leddormene (Annelida) består av gruppene flerbørstemark (Polychatea), fåbørstemark (Oligiochatea), igler (Hirudinea) og krogbærende pølseormer (Echinura).
Forfattere
Torkild Bakken Eivind Oug Svein Erik Sloreid Trond Bremnes Trond Knapp Haraldsen Dag DolmenSammendrag
Det er ikke registrert sammendrag