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.
2001
Sammendrag
Anthracnose caused by Colletotrichum acutatum J.H. Simmonds was detected in strawberry (Fragaria x ananassa Duch.) for the first time in Norway in 1999. Symptoms were found in greenhouse grown strawberries in the cultivar Korona. The article describes symptoms, identification, fungal characteristiques, and how Koch"s postulate was fulfilled
Sammendrag
Artikkelen gir et kort sammendrag av resultater fra forsøk med bruk av undervarme og nyttesopp som tiltak mot råtesopper i jordbær. Råtesoppene trenger fuktighet for infeksjon og sjukdomsutvikling. Varmerør under plantene har redusert luftfuktigheten og med det betydelig redusert faren for angrep av råtesopper. Ved å bruke nyttesoppen Trichoderma harzianum mot gråskimmelsoppen (Botrytis cinerea), er antallet råtne bær blitt ytterligere redusert
Sammendrag
Det vert rapportert frå felt- og laboratorieforsøk med bekjemping av gråskimmel (Botrytis cinerea) i jordbær ved hjelp av nyttesoppane Trichoderma harzianum og Gliocladium roseum. Jamt over var det for dårleg verknad av nyttesoppane til at dei kan tilrådast i kommersiell bruk i dag. Det var lovande effekt av forbehandling av soppsporer frå T. harzianum. Dette vil verta vidare prøvd ut i forsøk.
Sammendrag
For å nå styresmaktene sitt mål om at 10 % av arealet skal vere dyrka økologisk innan 2010 må ein innan økologisk fruktdyrking særleg løyse flaskehalasr knytt til økologisk plantevern. Gjennom prosjektet har ein i hovudsak arbeidd med både førebyggjande og direkte tiltak mot viktige skadedyr, sopp og ugras knytt til fruktproduksjonen.
Sammendrag
The present paper presents a summary of the most recent work on climatological conditions affecting ascospore discharge in Venturia inaequalis, the apple scab fungus, carried out at our two institutes. Experiments were performed under laboratory conditions by means of a wind tunnel and in the field using volumetric spore traps, either with artificial irrigation or under natural rain. One purpose of the studies was to reveal artificial laboratory conditions that could affect suppression of ascospore release normally observed under orchard conditions. Both air containing low relative humidity passing over leaf samples during simulated rain and extended maturation of the pseudothecial populations increased the number of spores released during darkness. These factors can thus explain some of the discrepancy between previously reported lab and field results. Field experiments with artificial irrigation showed that the possibility of high ascospore release during darkness increased once 80% or more of the season"s ascosporic inoculum had matured. The earlier observation of the stimulating effect red light has on ascospore release was confirmed. Under lab conditions, light intensities similar to what was recorded in the field around sunrise on rainy days, stimulated ascospore release. The rate of discharge increased with increasing light intensities up to a level normally occurring 2-3 hours after sunrise. When leaf samples were exposed to light and simulated rain in the lab, the rate of release increased over time. Thus, the delay in reaching the peak rate of ascospore release after sunrise may be due to the combined impact of increasing light intensity after sunrise and the intrinsic increase in rate of release over time. Ascospore release was monitored in the wind tunnel at temperatures of 1-8°C in daylight-balanced light. Low temperatures resulted in a lag phase in the cumulative distribution of ascospore release, where few or no ascospores were detected. The time until first detection of a given quantity of inoculum was inversely proportional to temperature. There was a reduction in the rate of release from 8 to 1°C, and consequently there was a reduction in the number of ascospores released at any given time. Where temperatures below 10°C coincided with continious rain and leaf wetness during night and day in field studies in Norway, few ascospores were released until 4-5 hours after sunrise. High quantities of ascospores were recorded during nights with dew in two Norwegian orchards. Episodes where more than 1% of the season"s inoculum was released during dew occurred around bloom of apple, and followed more than 2 days of fair weather (clear, warm days and cool, humid nights). Field studies showed that protracted dry periods with no or little rain not only delayed ascospore release, but also maturation, and consequently extended the season for ascospore release. Recommendations for management of the apple scab fungus are discussed.
Sammendrag
Godronia canker, caused by the fungus Godronia cassandrae f. sp. vaccinii, was detected for the first time on highbush blueberry (Vaccinium corymbosum) in Norway in 1995, and has caused severe stem wilting and dieback of young bushes. The disease was investigated over five years (1995-1999) in two experimental plantings, and in a survey carried out in 51 highbush blueberry plantings in Norway during the summer of 1998. Altogether, 31 cultivars were included in the investigations. None of the cultivars were completely resistant, but there were great differences in susceptibility. "Goldtraube" and "Hardyblue" were the most resistant cultivars, but "Bluetta" and "Patriot" also seemed to have low susceptibility to Godronia canker. "Ama", "Heerma" and "Spartan" had low to moderate susceptibility, "Berkeley", "Bluecrop", "Duke" and "Ivanhoe" had moderate to high susceptibility, and "Blueray", "Collins", "Earliblue", and "Jersey" were most susceptible. The latter four should not be recommended for highbush blueberry production in the cool, wet climate of Norway.
Sammendrag
Brassiceye® traps baited with ethylisothiocyanate were modified and used to collect adults of Delia radicum and D. floralis from the field to observe the infection level of Entomophthora muscae and Strongwellsea castrans. This study confirms that both E. muscae and S. castrans contain the basic properties to establish epidemics and act as important mortality factors in the field. Our results also suggest that E. muscae dominates under warm conditions and that S. castrans might be more dominating under cold conditions. The study also indicates that modified Brassiceye® traps are effective and very selective for D. radicum and D. floralis. Advantages and disadvantages of using different capture methods for fly population monitoring, pathogen sampling, and autodissemination are presented.
Sammendrag
Biodiversity studies of insect pathogenic fungi are normally conducted by the use of Galleria mellonella (Lepidoptera) or Tenebrio molitor (Coleoptera) as bait insects. These insects are easy to obtain and handle and large numbers of fungal isolates are often obtained by the use of these standard bait insects, but they usually yield only a limited number of fungal species. It was therefore an aim to compare the standard bait insect G. mellonella with Delia floralis (Diptera), a soil dwelling pest of Brassica vegetables, as bait insect. A method for baiting soil samples with D. floralis larvae was developed, and a systematic survey was conducted on soils from northern Norway for insect pathogenic fungi. Fungal species identified in the study were Beauveria bassiana, Fusarium merismoides, Metarhizium anisopliae and Tolypocladium cylindrosporum. T. cylindrosporum was found more frequently when using D. floralis as the bait insect than when using G. mellonella. Comparisons between the occurrences of insect pathogenic fungi in organically versus conventionally farmed soil have so far only been undertaken on a minor scale. This study therefore also aimed to compare the abundance of insect pathogenic fungi in organically and conventionally farmed soil and in soil from arable fields and the adjacent semi-natural field margins. The study showed a significantly higher occurrence of insect pathogenic fungi in soils from arable fields of organically managed farms. No significant differences in the occurrence of insect pathogenic fungi were, however, found between the field margins of the two cropping systems.
Sammendrag
Det er ikke registrert sammendrag
Forfattere
Toril Drabløs Eldhuset Berit Swensen Heleen A. de Wit Nina Davidsen Gro WollebækSammendrag
Det er ikke registrert sammendrag