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.
2011
Abstract
odronia canker (Godronia cassandrae f. sp. vaccinii) is a severe disease in young plantings of highbush blueberry (Vaccinium corymbosum L.) in Norway. In Europe, only the imperfect stage (Topospora myrtillii) has been reported, and thus conidia produced in pycnidia are assumed to be important for dissemination of the fungus. The seasonal pattern of production of conidia was investigated in a commercial planting of ‘Jersey" in 1998 and a research planting of ‘Bluecrop" in 1998 to 2000. The disease became apparent in March on shoots infected the preceding growing season, and lesions started to form pycnidia containing conidia in April. Samples of stems with distinct lesions of Godronia canker were collected from the bushes every two to three weeks from early spring to autumn. Stem pieces with lesions were shaken in water to release conidia from the pycnidia, and the numbers of conidia were determined by microscopy. Conidia were present throughout the growing season, but the highest numbers occurred during May, with 106 to more than 107 conidia per lesion. The numbers generally decreased during July to 20 % or less of that found in May, and decreased further during September to around 4 %. Ability to germinate remained high throughout the period conidia were trapped, from April to November/December. Options to manage the disease are discussed.
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Authors
Alhaji S. JengAbstract
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Espen GovasmarkAbstract
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Espen GovasmarkAbstract
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Abstract
The use of logging residues for bioenergy is encouraged in many countries, due to an increasing demand for renewable energy. However, there is concern that removal of logging residues may cause a long-term reduction in soil nutrient availability, reducing forest growth in the remaining stand. To quantify the growth response of Norway spruce and Scots pine to whole-three harvesting at first thinning a series of eight field experiments was set up in SE Norway in the seventies. Results after 25 years showed that whole-tree thinning lead to a decrease in forest growth. The effect was present more or less immediately after thinning, and was still present after 25 years. The average reduction in growth was around 10 % after 25 years in the spruce stands, while in the pine stands a non-significant average growth reduction of 4 % was found. The results are generated under experimental conditions, and in practice a share of the residues is left on site, decreasing the nutrient loss.
Authors
Hans Martin HanslinAbstract
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