PATHOGENICITY OF THE BLUE-STAIN FUNGI LEPTOGRAPHIUM-WINGFIELDII AND OPHIOSTOMA-MINUS TO SCOTS PINE - EFFECT OF TREE PRUNING AND INOCULUM DENSITY

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 Scots 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 0. minus.