Biological control of internal decay in Scots pine poles: A seven year experiment
P I Morris, D J Dickinson, B Calver
The interactions between key fungi were monitored, by non-destructive and destructive sampling methods, during the course of an experiment on the effectiveness of Scytalidium sp. and Trichoderma spp. for eliminating established infections of Lentinus lepideus (Fr. ex Fr.) Fr. in creosoted Pinus sylvestris poles. Although extensively isolated at the beginning and end of the experiment, Trichoderma spp. were unable to prevent colonization and decay of the non-creosoted wood by Lentinus lepideus at the crucial stage at around four years. Trichoderma sp. appeared to act as a primary or a secondary mould whereas Scytalidium and certain zygomycetes acted only as secondary moulds. At no stage in this experiment was Scytalidium isolated at the same high frequency as Lentinus lepideus or Trichoderma spp. Six and a half years after inoculation with Lentinus lepideus and five years after biological control treatment there was no difference in the extent of decay in the treated and untreated stubs. Biological control may therefore be best used for short term prophylactic treatment rather than long term or remedial treatment.