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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

The minirhizotron technique provides the opportunity to perform in situ measurements of fine root dynamics and obtain accurate estimates of fine root production and turnover. The objective of the present work was to determine the fine root longevity and mycorrhization in a Norway spruce chronosequence. The study was carried out on four stands of planted Norway spruce (Picea abies), approximately 10, 30, 60 and 120 years old, during 2001 and 2002. The stands were located at Nordmoen, a plain of sandy deposits in southeast Norway (60o15 N, 11o06 E). For the root turnover study, altogether 60 minirhizotrones were installed and images were processed.Individual fine roots were identified, their mycorrhization assessed, appearance and possible disappearance dated, and growth in length measured. The data set was subjected to a survival analysis, using a Kaplan-Meier product-limit approach. The minirhizotron samples were stratified according to stand age class, and Coxs F-test was used to analyze differences in survival estimates. The analysis may also be extended to consider other covariates such as tree species (spruce, pine or birch), understory vegetation, or soil depth. Typical survival function estimates will be presented, and the influence of stand age on the mycorrhization and the dynamics of the fine roots will be discussed.

Sammendrag

P.ramorum ble påvist I Norge for første gang i en planteskole i 2002. Etter første funn har patogenet vært påvist i mange planteskoler og hagesenter over store deler av landet. Det er funnet hovedsakelig på rhododendron, men også på Pieris japonica og Kalmia sp. Det er liten produksjon av rhododendron i Norge. I de fleste tilfeller, er påvisninger gjort i planter importert samme år. I 2005 ble P.ramorum funnet på etablerte busker av Viburnum fragrans og Rhododendron sp. i en privat hage og i flere grøntanlegg på Vestlandet

Sammendrag

Kortfattet oppslagsbok for bønder, skoleelever og andre, gjennomillustrert med korte tekster på alle de viktigste ugras, plantesjukdommer, skadedyr og næringsmangelprolemer i korn, potet, oljevekster og fôrvekster

Sammendrag

Det finnes flere nematode-arter som angriper korn. Biotester mot vanlige arter og patotyper av korncystenematoder ble gjennomført i 2005 og 2004 (Holgado & Andersson 2005). Resultatene viser til dels at flertallet kornsorter ikke er resistente mot alle forekommende arter og patogtyper, til dels at det finnes ulike grader av resistens i våre kornsorter. Bekjempelse av korncystenematoder med bruk av resistente kornsorter krever derfor kjennekap til hvilke arter og patotypere som forekommer i de enkelte feltene.

Sammendrag

Cereal cyst nematodes, Heterodera spp., are recognised throughout the world as economically important parasites of cereals. The virulence status on cereal cultivars differs between and within different species of the H. avenae-complex, and several pathotypes occur among them. A survey during 1995-2005 in Norway revealed that Heterodera spp. is common throughout the country. Studies in Norway have recorded H. filipjevi and also additional and possibly new species. A number of cereal cyst nematode populations from various regions of Norway, Sweden and the British Isles have been analysed using molecular, morphological and host range studies during the last three years. Fifteen populations, of the initial group of forty, are being studied more closely. Studies using isoelectric focusing and silver staining have detected divergent populations of H. avenae. The Swedish populations Ringsåsen seemed to be identical to a population found in Australia and the Swedish population Halland shows a protein profile separate from H. avenae. DNA studies are being used to determine if these populations are new species. An assortment of cereal cultivars, based on an international collection used for resistance testing, differentiates three groups, H. avenae (pathotypes Ha 11 and Ha 12), H. filipjevi (pathotype "West"), and a population from central Norway close to H. pratensis. Knowledge of the diversity of cereal cyst nematodes and their multiplication rates on their cereal hosts is of fundamental importance for efficient control strategies involving resistant cultivars. In Norway, management based on these parameters are in operation and have increased yields and profits to cereal farmers.