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
Ari Hietala Nina Elisabeth Nagy Arne Steffenrem Harald Kvaalen Carl Gunnar Fossdal Halvor SolheimSammendrag
Det er ikke registrert sammendrag
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Mite damage is often considered a spray induced problem. We monitored 12 Norwegian strawberry fields, 6 organic and 6 conventional fields, by sampling leaves two times per year for two years. Young folded leaflets were visually inspected for eggs and adults of strawberry mite (Phytonemus pallidus) and completely unfolded leaves were used for extraction of mobile stages of two-spotted spider mite (Tetranychys urticae). The spider mites were examined for infection of the mite-pathogenic fungus Neozygites floridana. Predatory mites (Phytoseiidae) were recorded on both leaf types, and the females mounted and identified. We also sampled leaves from selected plants in the boundary vegetation of most fields, to look for sources of T. urticae, phytoseiids and N. floridana, and soil from each field, to study the natural occurrence of entomopathogenic nematodes. We will present the results on abundance and diversity of the organisms investigated, and discuss similarities and differences between organic and conventional fields.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Colletotrichum acutatum is the causal agent of bitter rot in fruit crops (cherry, plum, apple, pear) and black spot in strawberry (Fragaria × ananassa). C. acutatum has also been isolated from a number of other cultivated and non-cultivated plant species; to date the fungus has been found on more than 25 different host species in Norway. The wide host range of C. acutatum necessitates research on the possibility of cross infection between alternative hosts and the potential of isolates of different origin to cause disease in strawberry. Planting healthy strawberry transplants adjacent to infected sweet cherry (Prunus avium) trees resulted in latent C. acutatum infections in the strawberry plants, indicating that cross infections between host species readily occur under field conditions. Molecular analyses (AFLP) have shown that isolates collected in Norway could be separated into three major phylogenetic groups in which isolates collected from either Prunus spp., Malus domestica or Fragaria × ananassa predominated. Two isolates from each of these groups were selected for experiments in vitro and in the field. Preliminary results indicate that isolates from all these groups are able to cause disease in strawberry, but that there may be differences in aggressiveness. In a field trial carried out in 2009 all six isolates caused symptoms in strawberry fruits when spore suspensions were applied three times during fruit development. The isolates from the Prunus group resulted in black spot on 42 and 53% of the strawberry fruits at harvest, while the corresponding numbers were 22 and 54% for the isolates from the Malus group, and 90 and 98% for the isolates from the Fragaria group.
Forfattere
Nina Johansen Ingeborg Klingen Nina Trandem Arild Andersen Øystein Kjos Richard Meadow Einar NordhusSammendrag
Resistens eller nedsatt følsomhet mot kjemiske skadedyrmidler er funnet hos flere skadedyrarter i bl.a. oljevekster, jordbær, potet og prydplanter i veksthus. Dette fører til bekjempelsesproblemer, økt sprøyting og risiko for resistens mot nye midler.
Forfattere
Leif Sundheim Maria-Luz Herrero Trond Rafoss Brita Toppe May Bente Brurberg Trond Hofsvang Christer Magnusson Anne Marte Tronsmo Bjørn ØklandSammendrag
Phytophthora ramorum S. Werres, A.W.A.M. de Cook & W.A. Man in‘t Veld is a newly described Phytophthora-species which is considered to be relatively recently introduced to both USA and Europe from an unknown area, or areas, of origin. The pathogen has a wide host range and causes a complexity of disease symptoms generally grouped into three categories: canker, foliage lesion, and dieback. In Europe the pathogen has been reported in 21 countries, Norway included; predominantly on ornamental plants in nurseries, but also outside nurseries in gardens and semi-natural environment, most often on rhododendrons. The Norwegian Food Safety Authority needs a risk assessment of the pest as basis for an evaluation of a future phytosanitary risk management of P. ramorum, including whether the organism should be regulated as a quarantine pest in Norway. On this background the Norwegian Food Safety Authority, in a letter of 22nd August 2008, requested a pest risk assessment of P. ramorum from the Norwegian Scientific Committee for Food Safety (Vitenskapskomiteen for mattrygghet, VKM). The pest risk assessment was adopted by VKM"s Panel on plant health (Panel 9) on a meeting 24th June 2009. VKM"s Panel 9 gives the following main conclusions of the risk assessment: 1) P. ramorum is present but not widely distributed in Norway, and the pest is under official control. The outdoors surveys of P. ramorum in Norway have not been conducted systematically over the whole country, and some uncertainty therefore still remains regarding the current distribution of P. ramorum in the PRA area. 2) The overall probability of entry of P. ramorum into Norway and the overall probability of establishment of P. ramorum in Norway are both rated as high with low levels of uncertainty; 3) In the absence of statutory control the probability for P. ramorum to be spread quickly in the PRA area by trade of host plants for planting is rated as high. The uncertainty of this assessment is low; 4) The part of the PRA area where presence of P. ramorum might result in economically important losses (the endangered area) is assessed to be most of the country of Norway, except where the climate is predicted to be unfavourable for the pest. However, this area must be regarded as a maximum estimate for the endangered area. On the other hand, a narrow and very conservative estimate for the endangered area can be defined based on the geographical distribution of highly susceptible host plants in Norway. This area is gardens and parks with Rhododendron spp., Viburnum spp. and F. sylvatica and areas in the wild into which Rhododendron spp. has spread and woods with F. sylvatica. Woods with F. sylvatica is limited to the county of Vestfold and some small areas in the counties of Aust-Agder and Hordaland; 5) P. ramorum is likely to have moderate economic impact on the nurseries in the PRA area with current phytosanitary measures. Without any such regulations P. ramorum is likely to have major economic impact on the nursery industry of the PRA area. The levels of uncertainties of these assessments are low; 6) With current phytosanitary measures P. ramorum is likely to have moderate economic impact on parks and private gardens in parts of the PRA area. Without any such regulations P. ramorum is likely to have major economic impact in the best climatic zones of the PRA area. The levels of uncertainties of these assessments are low; 7) The impact of P. ramorum in coniferous and mixed forests of the PRA area is likely to be minor. The level of uncertainty of this assessment is medium. The impact of P. ramorum in natural and planted deciduous broadleaf forests of the PRA area is likely to be minor due to the scattered and limited distribution of the most susceptible species. The level of uncertainty of this assessment is medium; 8) The non-commercial and environmental consequences to natural environments in the PRA area are likely to be moderate. The level of uncertainty ...
Forfattere
Venche Talgø Iben M. Thomsen Gary Chastagner Thomas Cech Kurt Lange Bernhard Perny Kathy Riley Benjamin Louis Andrew Dobson Sonja S. Klemsdal Arne StensvandSammendrag
As an attempt to settle the matter of the uncertain etiology of CSNN, an international research group with representatives from Austria, Denmark, Germany, Norway, and USA was established after the 8th International Christmas Tree Research & Extension Conference in Denmark in 2007.
Forfattere
Venche Talgø Jafar Razzaghian Trude L. Slørstad Sonja Klemsdal Terje Pundsnes Arne StensvandSammendrag
I prosjektet "Betre skjøtsel av viltveksande kristtorn som grunnlag for betre plantekvalitet og større utbyte", finansiert av Norsk Genressurssenter, vart det i 2006 sett i gang eit forsøk med beiting av sau og betre stell i eit villbestand av kristtorn i Rogaland. Bakgrunnen for dette var at bladfall og daude skot har vorte eit omfattande problem dei siste tiåra. Problemet ser ut til å ha auka i takt med gjengroinga av kulturlandskapet. Ein Fusarium-art, som ved DNA-analyse synte seg å vera mest lik F. acuminatum, ser ut til å vera hovudårsaka til skaden. Topping, tynning og oppstamming av kristtorn, rydding av buskar og kratt og beiting med sau over ein periode på fire år har gitt langt mindre sjukdom og betre kvalitet på kristtornen og auka salsverdien monaleg.
Forfattere
Venche Talgø Jafar Razzaghian Trude L. Slørstad Sonja Klemsdal Terje Pundsnes Arne StensvandSammendrag
Bladfall og daude skot har dei siste tiåra vorte eit omfattande problem i villbestand av kristtorn (Ilex aquifolium) langs sørvest kysten av Noreg. Fleire soppar vert ofte isolert i samband med skadane, men spesielt ein Fusarium-art, som ved DNA analyse synte seg å vera mest lik F. acuminatum, dominerar. Ved eit tilfelle vart den same Fusarium-arten funnen på daude skot på ei nordmannsedelgran (Abies nordmanniana). Soppangrepa på kristtorn er truleg eit resultat av aukande gjengroing på grunn av mindre beiting no enn tidlegare.