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Publications

NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.

2009

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Abstract

This is a final report for the project Norwegian Scenarios II, part two, that has been performed in collaboration between Bioforsk Plant Health and Plant Protection, The Norwegian University of Life Sciences and the Norwegian Food Safety Authority. The aim of the project was to establish Norwegian scenarios for the models PRZM and MACRO and to use them for approval of new pesticides.

Abstract

A phylogenetic analysis of ITS1-2 sequences from 117 specimens of Schistidium from Eurasia and North America revealed several new taxa within the genus. Schistidium sibiricum Ignatova & H.H. Blom, S. obscurum H.H. Blom, Köckinger & Ignatova, S. tenuinerve Ignatova & H.H. Blom, S. bakalinii Ignatova & H.H. Blom, S. echinatum Ignatova & H.H. Blom and S. succulentum Ignatova & H.H. Blom are described as new for science. Three new combinations are made: S. canadense (Dupr.) Ignatova & H.H. Blom, S. abrupticostatum (Bryhn) Ignatova & H.H. Blom and S. konoi (Broth.) Ignatova & H.H. Blom. Illustrations are provided for new species. A preliminary key for the identification of Schistidium species known in Russia is given.

Abstract

Development of ontogenic resistance to powdery mildew (Podosphaera aphanis) in strawberry fruit has not been quantified, and thus cannot be exploited in disease management programs. Four commercially-relevant strawberry cultivars were evaluated for ontogenic resistance to powdery mildew. Fruits were inoculated at one of the four growth stages: flowering, green, white and early pink fruit. There was a significant difference between and within cultivars at the bloom and green stage of inoculations (P <0.05) for both disease incidence and severity. On average 16.4, 39.5, 48.7, and 60.3 % of the fruits inoculated at bloom developed powdery mildew in cultivars Elan, Korona, Frida and Inga, respectively. None of the cultivars developed powdery mildew when inoculated at the pink stage. It may be concluded that flowers and green fruits of strawberry were much more susceptible to powdery mildew infection than white and pink fruits. The high susceptibility of cultivars at the flower and early green stages seemed coincident with the succulent nature of the fruits at these stages, making it easy for penetration and establishment of mildew. Control measures targeting at these critical windows of fruit susceptibility are likely to reduce yield loss.

Abstract

The Scots pine is widely used for pressure-treated transmission poles. Prior to preservation treatment, all capillary water must be dried off. Natural seasoning in open-air predominates, which implies that most drying takes place during the dry spring and warm summer seasons. The inventory of drying poles represents considerable value in a company’s balance sheet and risk of downgrading. There is risk both for keeping higher inventory than optimal and for treating poles that would not be dried sufficiently. Knowledge of drying times during the annual seasons has been insufficient. The objective of this study has been to work out a model for pole drying, based on a description of the pole itself and climatic observations during drying. The model has then been used to predict optimal drying times for various pole types and climatic conditions, for roofed or sheltered pole inventories, for assisted drying, etc.

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Abstract

Ophiostomatoid fungi were isolated from Scolytus ratzeburgi infesting Betula pendula and B. pubescens in Norway. Fungi were identified based on morphology, DNA sequence comparison for two gene regions and phylogenetic analyses. The most abundant fungus was Ophiostoma karelicum, suggesting a specific relationship between the fungus, the vector insect and the host tree. Our results suggest that O. karelicum occurs across the geographic range of S. ratzeburgi and its close relatedness to the Dutch elm disease fungi suggests that it could be important if introduced into other parts of the world. Other fungi, only occasionally isolated from S. ratzeburgi, were identified as O. quercus and a novel taxon, described here as O. denticiliatum sp. nov.