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
Artikkelen omhandlar skade av einerkvistdød (Phomopsis juniperovora) på bartre som vert brukt til juletre, dvs. edelgran (fleire artar av Abies) og vanleg gran (Picea abies).
Sammendrag
Det er observert mykje brune nåler på barlind dei siste 2-3 åra. Det er påvist angrep av einerkvistdød (Phomopsis juniperovora) i samband med desse skadane. Men også vinterskadar i kombinasjon med sekundære soppar kan vera årsak til skadane.
Sammendrag
Magnesiummangel gir store skadar på ulike bartre-artar brukt til klyppegrønt og juletre. I nokre felt med lawsonsypress (Chamaecyparis lawsoniana) har skadane vore så omfattande at baret ikkje er salsvare. Også i nordmannsedelgran (Abies nordmanniana) er det meldt om skadar. Artikkelen omtalar symptom, skadar, opptak av magnesium i plantene og tiltak for å hindra skadane
Sammendrag
Gjennom ei kartlegging av skadar i produksjon av klyppegrønt vart det funne store angrep av einerkvistdød (Phomopsis juniperovora) i krussypress (Chamaecyparis pisifera "Squarrosa"). Artikkelen omtalar symptom, skadar, biologi til skadesoppen og tiltak mot denne
Sammendrag
Under ei kartlegging av skadar i produksjon av klyppegrønt vart det funne store angrep av algesopp (Phytophthora) i lawsonsypress (Chamaecyparis lawsoniana). Artikkelen omtalar symptom, skadar, biologi til Phytophthora og tiltak mot sjukdomen
Sammendrag
Artikkelen rapporterer frå ei kartlegging av parasittære og andre soppar funne på ulike treaktige buskar og tre brukt til klyppegrønt
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
Seasonal production of spores (conidia) of Monilinia laxa (Aderh. & Ruhl) Honey on overwintering mummified fruits, blighted flowers and fruit spurs, and newly infected flowers of sweet cherry (Prunus avium L.) was investigated in Norway in 1997-1999. Infected plant parts were incubated in saturated air for 48 h prior to washing in distilled water, followed by a quantification of conidia from the spore suspensions with a light microscope. Mummified fruits or fruit spurs containing blighted flower and leaf parts, placed on the ground in the spring or the preceding autumn, more quickly depleted their inoculum compared to similar plant parts still hanging in trees. Conidia were produced in high numbers on mummified fruits left hanging in trees for 2-3 years after infection. In 1997, the conidial production on fruit mummies in trees was relatively even during the growing season. The year after, the highest sporulation on mummified fruits in trees occurred prior to flowering, and by harvest the sporulation was reduced by 92%. The wet weather that occurred in 1998 probably depleted the inoculum earlier than in 1997, when the summer was drier. The major production of conidia from fruit spurs occurred prior to or around bloom, and very few conidia were observed at harvest. Infected flower and leaf parts attached to the overwintering fruit spurs contained higher numbers of conidia than the fruit spurs themselves. Flowers infected in the spring produced most conidia during the first two months after infection, however, if remaining attached to the fruit spurs, they produced conidia during the entire season. Infected overwintered flowers produced 3-10% as many conidia as newly infected flowers in May and early June. The maximum production of conidia from single overwintered mummified fruits was more than 10 times the conidial production from an overwintered fruit spur or newly infected flower at their respective times of peak sporulation
Sammendrag
Three copper fungicides were tested in their effect against apple scab (Venturia inaequalis). Copper oxide and Copper oxychloride were the most effective against scab. Copper hydroxide was the least phytotoxic to apple foliage and fruit
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.