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.
2002
Sammendrag
Phytopththora infestans is an important pathogen on potato and tomato in Vietnam during the winter season. There are no earlier reports on studies of P. infestans populations in this country. During January 2002 leaf samples were collected from potato and tomato in three provinces in north of Vietnam; Lao Cai, Hanoi and Hai Phong. About 120 pure isolates were obtained. Results from testing of these isolates for mating type, metalaxyl resistance and mitochondrial DNA haplotype will be presented.
Forfattere
Anne Falk Øgaard Tore Krogstad Tor LunnanSammendrag
Uptake in grass crops of ammonium acetate lactate extractable K (KAL) and reserve K (interlayer K + structural K) in soil was studied in 16 field experiments at different locations on a range of mineral soil types in Norway. The K uptake from soil, both from KAL and reserve K, was considerable, often even at the highest level of K fertiliser. During three years, only on the sandy soils with a low level of acid soluble K (KHNO3 minus KAL) was there a yield response to K fertilisation. The KAL values declined rapidly and flattened off at a "minimum level" which differed with soil type. This minimum level for KAL is a useful parameter in fertiliser planning, because the grass usually took up the K in excess of the minimum level over two years. The minimum value of KAL was significantly correlated with the content of clay + silt in soil. The decrease in KAL during the growing season was closely correlated to the KAL value in spring minus the minimum value and, therefore, the amount of K supplied to the grass from the KAL fraction can be calculated. Furthermore, the KAL value for the following spring may be estimated. The release from reserve K was partially related to acid soluble K.
Forfattere
V.N. Pereverzev T.E. Sveistrup M.S. StrelkovaSammendrag
Opphoping av tungmataller (Ni og Cu) er undersøkt i tre sandige posoljordsmonn som var utsatt for varerende belastningsgrad av luftbåren forurensing fra ikke jernproduserende smelteverk. Størst opphoping ble funnet helt i overflata av det organiske sjiktet som virker som en biogeokjemisk barriære.
Forfattere
Aksel DøvingSammendrag
Teknisk utstyr og metodar for måling bærfastheit i jordbær har vore granska både gjennom litteraturstudium og gjennom omfattande forsøk. Det er også gjennomført forsøk med sammenlikning av bærfastheit og andre kvalitetseigenskapar i bæret. Nokon standardisert metode er ikkje kjend. Dei mange metodane som har vore brukte i forsøk har ulik verkemåte og har ofte gitt ulike resultat. I forsøka ved NLH vart det i mange høve funne låge korrelasjonar mellom ulike metodar. "Eisenhuths metode" er ein billeg metode, den er enkel å utføre, påliteleg og rask, og har såleis mange fordelar framfor dei dyrare og meir kompliserte instrumenta. "Eisenhuths metode" går ut på fylle bær i ein sylinder, sette eit lodd på toppen av bæra, og så måle kompresjonen. Tre instrument som måler fastheit på enkeltbær har gitt pålitelege resultat, Bareiss, Instron og Texture Analyser. Bareiss er billegare, enklare og raskare å bruke enn dei to andre. Storleiken på kvar bærprøve er her foreslått til 300-500 g for "Eisenhuths metode" og 25-50 bær for metodar som måler på enkeltbær. Det vart funne store variasjonar i fastheit og refraktometerverdi mellom enkeltbær, særleg i `Korona". Variasjonen i farge var mindre. Det var stor skilnad i fastleik mellom sortar, men rangeringa var avhengig av metode for fastheitsmåling. Korrelasjonane mellom bærfastheit, refraktometerverdi og farge var låge, og ikkje alltid signifikante. Fastleik etter lagring ved ulike temperaturar var avhengig av målemetode. Fastleiken er også avhengig av kjernetemperaturen i bæret ved måling, bæra var blautare ved 20 "C enn ved lågare temperaturar.
Sammendrag
Survey of insecticide resistance in different populations of Myzus persicae collected from field and greenhouses in Norway.
Forfattere
Reidun Pommeresche Reidun PommerescheSammendrag
This study focusses on the spider fauna in two organically managed leys in different stages of a crop rotation and in one permanent pasture, all on the Tingvoll Farm in northwestern Norway. Spiders were collected by means of pitfall traps; the sampling period lasted from 28 April to 23 June 2000. Altogether 2415 specimens, representing 48 species, were found. A DCA-analysis shows differences in the spider populations found in the leys compared with the pasture, but less difference between the young and older ley. However, the number of species and the dominance pattern of the spider populations differ between the young and older ley. A total of 16 species were found in the young ley, 26 species in the older ley and 34 species in the pasture. Bathyphantes gracilis, Erigone atra, Oedothorax fuscus and Savignia frontata were the most abundant species in the leys, with Pardosa amentata and Silometopus elegans the most abundant in the pasture. Collinsia inerrans was represented by 83 specimens in the leys. This species is previously recorded only twice in Norway, and has been placed on the national Red List proposal.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Birgitte HenriksenSammendrag
Det er ikke registrert sammendrag
Forfattere
Birgitte HenriksenSammendrag
A Norwegian project was started in order to investigate the possibilities for controlling seed borne diseases in organic cereal seed production. A main part of the project has been to test alternatives to chemical seed treatments against barley leaf stripe (Drechslera graminea), and loose smut in barley and oats (Ustilago nuda f. sp. hordei, Ustilago avenae). The effect of different formulations of fermented milk products, horse-radish, hot steam treatment and different concentrations of acetic acid were investigated in field trials during 2001 and 2002. Only naturally infected seeds were used in the investigation. The treatment dosage used was 20 ml per kg seed except for horse radish that was used at dosages of 40 and 60 ml per kg (20% suspension). Hot steam treatment was performed at 100% RH , 55° and 60°C (30, 60 and 90 min) in a steam chamber developed for steaming plants and equipment used in greenhouses. In 2001 acetic acid was tested at concentrations of 20% and 35%, while in 2002, 25% and 30% were tested as well. Within two weeks after treatment the seeds were counted and planted in rows of 100 seeds with 10 replicates. Fields were sited in three different regions of Norway. Emerged seedlings were counted after three weeks and infected plants were registered after heading. In 2001 number of plants with symptoms of barley leaf stripe and loose smut of oats were significantly lower after acetic acid treatment than after no treatment. Both concentrations (20% and 35%) had effect on the two diseases. Effect of acetic acid was found in all the three fields. In laboratory tests, 35% acetic acid reduced germination slightly, while 20% did not have any negative effect on germination. Horse-radish had little effect towards these diseases. When mixed (50/50) with acetic acid (35%), horse-radish had the same effect as 20% acetic acid alone. Only one of the fermented milk products reduced the number of diseased plants (significantly in one field). Hot steam treatment had negligible or small effect at the lowest temperatures. After treatment in 60°C for 60 and 90 min., effect on the diseases increased, but negative effects on germination increased as well. In 2002, the development of barley leaf stripe symptoms and loose smut in oats was poor. In the fields with loose smut of barley however, the development of smutted heads were significant. Reduction in number of smutted heads was detected in the field after acetic acid treatment compared to no treatment. Thus the effect of 20 ml acetic acid per kg seed, used in 20, 25 or 30% concentration, so far appears promising towards the diseases tested.