The effect of stand density on the susceptibility of Pinus sylvestris to Gremmeniella abietina

Abstract

The susceptibility of a 20‐year‐old Scots pine stand to Scleroderris canker caused by Gremmeniella abietina was monitored in relation to stocking density. The data included five densities varying from 800 to 5 000 trees/ha. The degree of damage, as indicated by the proportion of brown needles and the number of dead trees, correlated positively with the stand density. The proportion of dead trees was low at densities below 1 100 trees/ha, but increased linearly with increasing density.