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.
2009
Forfattere
May-Guri Saethre Trond HofsvangSammendrag
Det er ikke registrert sammendrag
Forfattere
May-Guri Saethre Ole Tobias Rannestad Amon MaerereSammendrag
Det er ikke registrert sammendrag
Forfattere
May-Guri Saethre Arnstein Staverløkk Trond HofsvangSammendrag
The history of Harmonia axyridis and a summary of surveillance & research in Norway till June 2009 are given. H. axyridis was assessed as a potential bio-control agent for use in Norwegian greenhouses in 2001. The risk of establishment outdoors was assessed too high and no permission was given. The first record in Norway was in 2006 when one adult was found on Thuja sp. imported from the Netherlands. In late 2007 and throughout 2008 adults were found indoors/outdoors at several locations in the Oslo-area. Establishment outdoors became evident. Observations in Aust-Agder and Vestfold revealed further spread/introduction to new areas. The bioclimatic potential of H. axyridis was assessed in 2007 by the aid of CLIMEX and national agrometeorological data, showed that suboptimal microclimates for the species can be found in the coastal areas of the south. In late 2008 a web-site was launched aiming to engage the public to submit observations on-line and has contributed to monitor development of the species across the country. Competition experiments with H. axyridis and Coccinella septempunctata in 2008/2009 showed that only H. axyridis eggs & larvae survived when the two species were mixed.
Forfattere
Ignace Godonou Segolene Leclercq Ghislain Tepa Yoto Braima James May-Guri SaethreSammendrag
Aphids are recognised worldwide as economically important pests in vegetable production systems. Synthetic pesticides are used against aphids and pose a great risk to the environment, human health and beneficial biodiversity. Aphid species, their natural enemies, their vegetable and weed hosts were poorly documented in Benin. A study was undertaken at 31 vegetable production sites across Benin to identify the aphid species, their host plants, and their natural enemies. The level of aphid infestation and damage to vegetables were also recorded. 17 out of 31 vegetable species surveyed were commonly infested and damaged by aphids. Aphis gossypii, Aphis craccivora and Lipaphis erysimi were recorded on a wide range of vegetable species, while Myzus persicae where recorded on Brassica rapa and Solanum macrocarpon only. 44 weeds where recorded associated with vegetables and 25 where infested with aphids. Commelina benghalensis, Trianthema portulacastrum and Euphorbia hirta were the weeds heavily infested. The most commonly encountered aphid predators where Cheilomenes propinqua, Cheilomenes sulphurea, and Ischiodon aegyptius. The widely distributed aphid parasitoid Lysiphlebus testaceipes were often found attacking A. gossypii and A. craccivora. Further studies will be carried out to assess the potential of these natural enemies in an integrated pest management strategy against aphids.
Forfattere
Anne Kjersti Bakken Tor Lunnan Mats HøglindSammendrag
Det har tradisjonelt vore sterkast fokus på kvaliteten i førsteslåtten. For dei som ønskjer grovfôr med høg potensiell næringsverdi, har oppskrifta vore å hauste denne tidleg. Ein skal samtidig planlegge utfrå at tidleg førsteslått gjer at ein stor andel av årsavlinga må takast i seinare slåttar. Det er ikkje gitt at alt grovfôret ein haustar i sesongen må halde høg eller like høg kvalitet, men nokre husdyrprodusentar kan ha dette som mål. Det vil da vere viktig å gjere ei totaltilpassing når det gjeld tal haustingar og haustetider. Vi presenterer her resultat som viser at det er viktig å hauste også andre- og tredjeslåttar tidleg dersom ein vil ha høg kvalitet i heile årsavlinga.
Sammendrag
Peruskjellfrø tilhører den biologiske gruppen sommerettårige ugras. Planten har en greinet pålerot, og kan bli 20-80 cm høy. Stengelen er opprett, greinet, av og til med tre greiner fra samme bladfeste, og korthåret i toppen. Bladene er motsatte og rundtagget. De nederste er kortstilket, eggformet og tilspisset, de øvre er omtrent sittende, avlange og lansettformet. Planten har mange små prestekrageliknende korger. Frukten er en nøtt med fnokk, her representert som frynsete eller helt oppflisete skjell, og som i tørrvær brer seg ut som en fallskjerm, slik at fruktene fyker av gårde med vinden. Forekommer i åpen åker, på avfallsplasser og veikanter. Liker best leirjord, synes å tilpasse seg mange typer jordarter og fuktighetsforhold. Er varmekjær og ømfintlig for frost. Opptrer som ugras i alle slags åkerkulturer, og spesielt i byer, hage og gartnerier. Mindre brysom i Skandinavia. Stammer opprinnelig fra Peru i Sør-Amerika, og ble introdusert til botanisk hage i Madrid i 1790-årene. Kom til Norge i 1830. Kan bekjempes som andre sommerettårige ugrasarter.
Forfattere
Anders Aak Anders AakSammendrag
Blowflies of the species Calliphora vicina are causing severe economic losses in dried fish production in northern Norway. Female flies are attracted to dead animals for both oviposition and foraging. As natural decomposing carcasses are scarce in its distribution and only suitable for the larvae a short time, the odour mediated resource location is expected to be very important. A wind tunnel was used to optimize attraction of female C. vicina and chemicals known to attract blowflies were tested both as single compounds and in blends. A three-component blend of dimethyltrisulphide, mercaptoethanol and o-cresol was found to significantly increase upwind orientation compared to the single attractant dimethyltrisulpide. More than 60% of female flies showed upwind oriented flight to the synthetic blend and this attraction was similar to decomposing liver which is commonly used to trap blowflies. Female attraction to odours from dead animals reached 90%, indicating a large potential for lure improvement. The three-component blend significantly increased field catches compared to dimethyltrisulphide, and the catch consisted of 98.2% females. A large scale mass trapping experiment in Lofoten, northern Norway, has now been ongoing for four years. Damage to stockfish in treated areas has significantly decreased compared to control areas.
Forfattere
Geir Kjølberg KnudsenSammendrag
Det er ikke registrert sammendrag
Forfattere
Geir Kjølberg Knudsen Anders AakSammendrag
Det er ikke registrert sammendrag
Forfattere
Per Stålnacke Annelene Pengerud Marianne Bechmann Josette Garnier Christoph Humborg Vladimir NovotnySammendrag
The major objective of this study was to compile and examine empirical relationships between the driving forces and pressures that affect nitrogen cycling. Special attention was paid to riverine loads, fluxes, and concentrations of nitrogen in relation to agricultural factors (e.g., land use and fertilisers) at various spatial scales (plot, field, catchment, river basin, nation, region, continent, and world). Results of the present analyses and assessments reported in the literature indicate that at global, continental and inter-river basin scales, the level of riverine nitrogen loads (pressures) can be readily derived from simple empirical relationships with driving forces like population density and agricultural factors (e.g., proportion of arable land and fertiliser use). It seems that statistically derived relationships do not hold or are much weaker at the scales of single river basins and smaller catchments, whereas nitrogen losses appear to be correlated with fertiliser use at the smallest scales (plot and field). It is important to recognize this spatial nutrient paradox, particularly when such functional relationships are applied in the contexts of management and decision making. The implications for management are given further consideration in this paper.