Infection of Pruning Wounds in Scots Pine by Phacidium coniferarum and Selection of Pruning Season

Helsinki

1990

35 S.

15 Abb., 5 Tab., zahlr. Lit. Ang.

Bandaufführung

2623

36956

The Scots pine pruning experiments were established in different geographical regions of Finland. The pines were pruned at 16 different times during the year. Half of the trees were inoculated with conidia of P. coniferarum. Annual cankers were produced in the inoculated trees pruned during October - December. The safe pruning season ended in autumn when the five-day mean temperature decreased below +7C. The unsafe pruning season terminated when the temperature remained permanently < 0C. Dry-pruned branches were infected only of the phloem had been wounded. The mycelia of the fungus were pathogenic inthe phloem inthe inoculations made from October to March. The fungus occurred commonly in slash and in pines wounded during the autumn. The fungus has a one-year life cycle.