Growth phase of bare-root Scots pine seedlings and their susceptibility to Gremmeniella abietina
Bare-root row-sown seedlings of Scots pine (Pinus sylvestris L.) in a forest nursery were inoculated with Gremmeniella abietina conidia at different times during their first and second growing seasons. The following spring, the proportion of diseased seedlings was different in various inoculation time treatments according to the age of the seedlings. The first year seedlings were susceptible to infection until late summer, whereas the second year seedlings were not. It is thought that this difference is due to the different growth rhythms of the first and second year seedlings. The difference in the susceptibility of bare-root seedlings to the disease in various growth corresponded to that reported earlier for container seedlings.
Received 10 March 1999 Accepted 7 September 1999 Published 31 December 1999