The susceptibility of Scots pine seedlings to Gremmeniella abietina: effect of growth phase, cold and drought stress.

This article focuses on effects of pruning young Scots pines on host vigour and susceptibility to two blue-stain fungi Leptographium wingfieldii and Ophiostoma minus associated with pine shoot beetle Tomicus piniperda. Tomicus piniperda were inoculated into 25-year old Scots pines. Both fungi invaded the inner bark and the sapwood at the points of inoculation. Leptographium wingfieldii caused larger lesions in the bark but Ophiostoma minus tended to grow faster in the sapwood. The lesion formation and the content of resin acids in lesion did not differ between fungi.