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 Mo relet and Ophiostoma minus (Hedgc.) H. et P. Syd., associated with the pine shoot beetle Tomicus piniperda (L.), was determined on pruned an d unpruned Scots pine (Pinus sylvestris L.) trees. Both fungi killed u npruned trees when inoculated in a 60 cm wide band at a density of 800 inoculations/m2, while severely pruned trees were killed by an inocul ation density of 400 inoculations/m2. Trees inoculated with L wingfiel dii died sooner after inoculation than trees inoculated with 0. minus.