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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

Sammendrag

Foredraget ga en gjennomgang av risiko for utvikling av resistens og anbefalte strategier for å unngå det, samt en vurdering av behov og strategier under forholdene i Østfold sommeren 2006

Sammendrag

Increasing levels of Fusarium mycotoxins have been recorded in Norwegian cereals during the last few years. In 2004, unusual high levels of deoxynivalenol (DON) were recorded, in particular in oats (e.g. 25-30 000 ppb) and some alarming levels of T-2 and HT-2 were recorded in 2005, also in oats. Due to the lack of effective control measures, FHB and mycotoxin contamination poses a significant threat to the yield and quality of cereals. Today only a very limited number of check samples of grains used for food and fodder are tested for mycotoxin content. To reduce the risk of contaminated cereals entering the food and feed processing chain, a four-year project (2006-2009) has been started, with the aim to develop a strategy for identification and discarding of unsuitable grain lots. Because there will be impracticable to analyse every lot the basis for a three-step screening system will be established: 1 - Development of prediction models based on information about effects of agronomic/cultivation practice and climatic conditions, for selection of putative `high-risk" fields/lots; 2 " Selection of a suitable and rapid testing method with capacity to screen a large number of samples for relevant mycotoxins at low costs, for testing of `high-risk" lots; 3 " Chemical toxin analyses of grain lots found to be highly contaminated in step 2. Fusarium avenaceum , F. culmorum, F. poae and F. tricinctum have been the most frequently recorded Fusarium species on cereals in Norway for many years. However, more recently also F. graminearum has occurred more frequently and F. langsethia has been detected especially in oats. Investigations will be carried out to see if there has been a change in the composition of Fusarium species.

Sammendrag

Aktiviteten til overvintrede jordbærsnutebiller (Anthonomus rubi), målt som avkuttede knopper og voksne biller, ble registrert ukentlig i sprøytede og usprøytede ruter i unge og gamle jordbærplanter. Studiet ble gjort i 9 Koronafelter i år 2000, i et distrikt med mye A. rubi på Østlandet (Nes i Hedmark).  Totalt antall avbitte knopper var sterkt korrelert med totalt antall biller som ble funnet ved å riste enkeltplanter over et hvitt fat. En økning i antall voksne biller ble som regel etterfulgt av en økning i skadede knopper 1-2 uker senere. Dette viser at overvåking ved hjelp av fatmetoden har potensiale for å  forutsi skade. I fem av seks felter der avlingen ble registrert ble det funnet en negativ sammenheng mellom avkuttede knopper og salgbar avling. Effekten av skadedyrsprøyting (flere sprøytinger i de fleste feltene) var relativt liten: Antall avbitte knopper gikk bare ned med 21% i forhold til usprøytede ruter, mens salgbar avling økte med 16%. Sprøytingen hindret altså en relativt liten del av den omfattende A. rubi skaden i jordbærfeltene som her ble studert, og det er siden funnet resistens mot skadedyrmidler i billlene.

Sammendrag

In this study, forest treated with different strengths of selective cutting (2570 % of volume removed) was remeasured after twelve years in 2005. At each of the sixteen 0.2 ha plots, including four repeats of each treatment, all trees larger than dbh 2.5 cm were calipered. We investigated growth, changes in stand structure, tree age, tree damage and crown condition.The diameter distribution displayed a reverse J-curve at all plots both before and after the cuttings. Twelve years later the curve is only slightly changed. Increment cores from 300 trees were taken to analyse annual growth reactions in different diameter classes. Most trees reacted with increased growth from the second or third year after the cutting.This improved growth accelerated the following six or seven years with 20-80% increase. Both small and large trees reacted, including severely suppressed trees. The initial crown volume and crown vitality after cutting is essential for the increased growth since several years are necessary to build up a larger and better crown. The relationship between increased growth and reduced volume per hectare indicates less competition between trees regarding nutrients and light after the cutting.