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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.

1993

Abstract

In a field experiment in central Sweden, the vigour of 25-yr-old Scots pines was manipulated by pruning, prior to inoculation with Leptographium wingfieldii and Ophiostoma minus, two blue-stain fungi associated with Tomicus piniperda. Our main purpose was to correlate fungus invasion and host defence reactions with host vigour. Both fungi invaded the inner bark and the sapwood at the points of inoculation. L. wingfieldii caused larger lesions in the bark, but O. minus tended to grow faster in the sapwood. The flow of primary resin was related to tree vigour, whereas carbohydrates present in needles and stem phloem were not. Lesion formation and the content or composition of resin acids in lesions did not differ between fungi or pruning treatments.

Abstract

The pathogenicity of the blue-stain fungi Leptographium wingfieldii Morelet and Ophiostoma minus (Hedgc.) H. et P. Syd. associated with the pine shoot beetle Tomicus piniperda (L.), was determined on pruned and unpruned Seots pine (Pinus sylvestris L.) trees. Both fungi killed unpruned trees when inoculated in a 60 cm wide band at a density of 800 inoculations/m2, while severely pruned trees were killed by an inoculation density of 400 inoculations/m2. Trees inoculated with L. wingfieldii died sooner after inoculation than trees inoculated with O. minus.