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.
2011
Sammendrag
Dieback of European ash (Fraxinus excelsior), caused by the ascomycete Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea), started around 1992 in Poland and has since then spread over large geographical areas. By November 2010, the disease had been recorded in 22 European countries. The gradual expansion and high intensity of the ash dieback epidemic in Europe may suggest that H. pseudoalbidus is an invasive alien organism. In Norway, ash dieback was first reported in spring 2008, and a survey in early summer of the same year revealed that the disease had spread over large parts of the southern and eastern regions of the country. The distance from the southernmost to the northernmost infected stands was, at that time, about 400 km. Some old necrotic lesions were also observed, indicating that the ash dieback pathogen is likely to have been present in Norway since at least 2006. In 2009, a spore sampler was installed in a diseased ash stand at Ås, South-Eastern Norway. Sampling started in late July and continued until late September. Large numbers of ascospores resembling those of H. pseudoalbidus were observed, with the maximum number of spores occurring from the end of July to mid-August. The deposition of ascospores occurred mainly between 6 and 8 a.m. Ascospores are most likely to be the primary source initiating host infections and responsible for the rapid recent spread of H. pseudoalbidus in Europe.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Enkelte mener å ha observert at det var mindre skader på asketrær i 2010 enn året før og tror at bekymringen for askens framtid er betydelig overdreven. På våre overvåkingsflater har vi i 2010 registrert en liten nedgang i kronetetthet, og vi ser også at askeskuddsjuken er på stadig frammarsj både i Norge og i Europa ellers. Så det er all grunn til fortsatt bekymring.
Sammendrag
Colletotrichum acutatum causes black spot in strawberry (Fragaria × ananassa), but it has also been isolated from 30 other cultivated and non-cultivated plant species in Norway, including almost all fruit and berry crops. Bitter rot, which is caused by C. acutatum, is a severe disease in sweet and sour cherry and apple. We have studied the possibility of cross infection of isolates from other hosts and the potential aggressiveness of these isolates on strawberry. 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. Experiments were carried out under laboratory, greenhouse and field conditions, and strawberry fruits, leaves and stolons were inoculated. All experiments showed that isolates originating from the Fragaria group was much more aggressive than those from the other two groups. If detached strawberry fruits were wounded at time of inoculation, isolates from all groups developed black spot, but disease development went much slower for isolates from the Prunus or Malus groups. If not wounded, there was no or hardly any disease development caused by isolates from the latter two groups. On whole plants inoculated in the greenhouse, isolates in the Fragaria group developed an incidence of 27 to 28 % flower and fruit infections compared to 0 to 4 % for isolates from the other two groups. Under field conditions, Fragaria group isolates developed 50 to 70 % more infected fruit than the others at harvest. On stolons, we inoculated by wounding, and differences in aggressiveness between isolates were only minor. On strawberry leaf laminas, we observed that the ability to colonize the leaf surface was much larger for isolates from the Fragaria group compared to those from the other two groups. However, planting healthy strawberry transplants adjacent to infected sweet cherry trees resulted in latent infections of C. acutatum on strawberry leaves (but no visible infections on fruits), indicating that cross infection between host species may occur under field conditions.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Skade av soppen Sclerophoma sp. er eit relativt stort problem i juletreproduksjonen i Rogaland. Dette heng truleg saman med at det fuktige og milde klimaet der er gunstig for soppen. I smitteforsøk har vi oppnådd tilsvarande symptom som i felt. Vidare indikerar forsøk i laboratorium at fleire soppmiddel kan vera aktuelle å prøva ut i felt mot denne sjukdomen.
Sammendrag
Arter innen Phytophthora-slekten kan forårsake alvorlige sykdommer på trær. Økende handel påskynder spredning av ulike plantepatogener, og det er flere eksempler på at nye sykdommer forårsaket av arter innen Phytophthora-slekten er under utvikling i Europa.
Sammendrag
Det er ikke registrert sammendrag
Sammendrag
Fusarium langsethiae is a recently characterized fungus within the genus Fusarium. It is found as a grain contaminant of small grain cereals such as oats and barley, and to a lesser extent wheat. Fusarium langsethiae is particularly widespread in the Nordic countries and the UK where it poses a serious problem as the main producer of T-2 and HT-2 mycotoxins. The biology of F. langsethiae and its interaction with the plant remains poorly understood, partly hampered by difficulties reproducing a natural level of infection under controlled conditions. The reported study was designed as a series of glasshouse experiments to advance our understanding of F. langsethiae biology by investigating alternative infection routes and its proliferation in oats, Avena sativa. Various methods of seed, soil, and seedling inoculation, boot injection and spray inoculation, were tested. The results clearly show a strong preference of F. langsethiae for the panicle, ruling out alternative infection routes. At relatively low temperatures spray infection, accompanied by prolonged humidity, ensured a thorough establishment of the fungus both at flowering and at early dough stage. Boot injection proved to be a reliable working tool for production of an even and predictable grain infection. Apart from in the panicle, considerable fungal proliferation was only detected in flag leaf nodes, and was a direct consequence of the boot injection method. Fungal presence in the node tissue also correlated with significant stunting of infected shoots. In light of the results the pathogenic and endophytic abilities of F. langsethiae are discussed.
Sammendrag
Dette er en kort gjennomgang av været i vekstsesongen 2011 basert på data registrert ved Bioforsks værstasjoner og noen detaljer hentet fra klimatologiske oversikter utgitt av Meteorologisk institutt. Temperatur- og nedbørdata viser at det i perioden mai til september var varmere og våtere enn normalt de fleste steder. Enkelte stasjoner på sentrale deler av Østlandet hadde litt lavere varmesum enn normalt, mens det ved våre stasjoner nord for Bodø var betydelig tørrere enn normalt.