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
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Forfattere
Venche TalgøSammendrag
Det er ikke registrert sammendrag
Forfattere
David M. Gadoury Belachew Asalf M. Catherine Heidenreich Maria Luz Herrero Mary Jean Welser Robert C. Seem Anne Marte Tronsmo Arne StensvandSammendrag
A collection of clonal isolates of Podosphaera aphanis was heterothallic, and was composed of two mutually exclusive mating types. Cleistothecial initials approximately 30 µm were observed within 7 to 14 days after pairing of compatible isolates and developed into morphologically mature ascocarps within 4 weeks on both potted plants maintained in isolation and in field plantings in New York, USA and southern Norway. Ascospores progressed through a lengthy maturation process over winter, during which (i) the conspicuous epiplasm of the ascus was absorbed, (ii) the osmotic potential of the ascospore cytoplasm increased, resulting in bursting of prematurely-freed spores in water, and finally (iii) the development of physiologically mature, germinable, and infectious ascospores. Release of overwintered ascospores from field collections was coincident with renewed plant growth in spring. Overwintered cleistothecia readily dehisced when wetted, and released ascospores onto glass slides, detached strawberry leaves, and leaves of potted plants. Plant material so exposed to discharged ascospores developed macroscopically-visible mildew colonies within 7 to 10 days while non-inoculated controls remained mildew free. Scanning electron and light microscopy studies revealed that cleistothecia of P. aphanis were enmeshed within a dense mat of hyphae on the persistent leaves of field-grown strawberry plants, and were highly resistant to removal by rain while these leaves remained alive. In contrast, morphologically mature cleistothecia on leaves of 11 deciduous perennial plant species were readily detached by simulated rain and seemed adapted for passive dispersal by rain to other substrates. Contrary to many previous reports, cleistothecia appear to be a functional source of primary inoculum for strawberry powdery mildew. They furthermore differ substantially from cleistothecia of powdery mildews of many deciduous perennial plants in their propensity to remain attached to the persistent leaves of their host during the intercrop period.
Sammendrag
Gråskimmel (Botrytis cinerea) gir ofte store avlingstap i jordbær. Smitten må ein rekne med finst i alle jordbærfelt, og det er derfor uråd å unngå smitte heilt. Regntak eller plasttunnelar er sikraste tiltaket mot gråskimmel i økologisk jordbærdyrking. Det vernar plantene mot regn og doggfall, og tørrare planter gir mindre problem med gråskimmel.
Forfattere
Arne StensvandSammendrag
Det er ikke registrert sammendrag
Forfattere
Arne StensvandSammendrag
Foredrag om biologi/epidemiologi og tiltak mot mjøldogg i jordbær.
Forfattere
Arne StensvandSammendrag
Plantevernleksikonet. Skadegjørere: Jordbærøyeflekk Jordbærmjøldogg Bakteriebladflekk på jordbærFor hver skadegjører gis en oversikt over symptomer/skadevirkning, vertplanter, overlevelse og spredning og bekjempelse.
Forfattere
Arne StensvandSammendrag
Det er ikke registrert sammendrag
Sammendrag
Red stele in strawberry is caused by the oomycete Phytophthora fragariae. To prevent the introduction of the pathogen to Norway, it has been prohibited to import planting material of Fragaria spp. to the country since 1986. During 1995 to 1997 the Food Authority had a country-wide survey to reveal if P. fragariae was present. The pathogen was found in three separate regions: (i) Hedmark County, along the Mjøsa lake; (ii) Aust-Agder and Vest-Agder Counties, in coastal areas; (iii) Rogaland and Hordaland Counties, along the western border between the two counties. In the latter area there were clear indications of spread of infected plant material from a small certified nursery where P. fragariae was detected. All strawberry farms that had received plants from the nursery were thoroughly investigated and further sales of planting material was stopped. All other incidences in the 1995-97 survey were among strawberry fruit producers. In 2006 and 2007 there were two new detections of red stele in Vest-Agder, and one of the growers had produced and forwarded non-certified planting material to other strawberry growers. In 2008, a new country-wide survey was initiated, and the pathogen was found at a few new production sites for strawberry fruits in Hedmark and at one site in Vestfold County (in south eastern Norway). In 2009, red stele was also discovered at one site in Møre og Romsdal County (in western Norway). Totally, red stele has been found at 19 production sites in Norway. Since the mid 1990"s there have been no discoveries of red stele among certified plant producers. Sites where P. fragariae has been detected may continue to produce strawberry fruit for sale, but all production of strawberry plants or other planting material for further distribution is prohibited. For strawberry production on soil infested with P. fragariae, buffer zones to neighboring fields and creeks/rivers are required. No strawberry production can take place in the buffer zones, and normally the zones should be at least 100 m wide, but topographic and other conditions locally may increase or decrease the width of the zones. There are also restrictions on sharing machinery and equipment with other farms, and soil from infested farms may not be moved out of the farm. Testing of plant material is done by a root tip bait test and PCR.