AN INTEGRATED APPROACH, USING BIOLOGICAL AND CHEMICAL CONTROL, TO PREVENT BLUE STAIN IN PINE LOGS

Biological control of detrimental blue stain fungi has been demonstrated in field experiments using a nonpigmented strain of Ophiostoma piliferum, Cartapip-97(TM), to inoculate logs. In two field trials 78-97% and 95-99% of wood chips sampled from the sapwood yielded the nonpigmented strain of O. piliferum (NPOP) 8 weeks after inoculation. Wood chip isolations yielding blue stain fungi from the sapwood in noninoculated treatments after 8 weeks ranged from 53 to 83% during the first field trial and 6 to 31% during the second, whereas isolations from NPOP-inoculated treatments ranged from 0 to 3% in the first trial and 0% in the second trial. Phanerochaete gigantea had also colonized the sapwood of all treatments by 24 and 52 weeks, with 20-93% of chip samples in field trial one yielding P. gigantea, and 54-99% for field trial two. Effective control of bark beetles was demonstrated with applications of Dursban 4E. Bark beetle colonization in Dursban-treated logs was less than 3%, a 9-47% decrease when compared to other treatments. Successful control of blue stain fungi appears possible by treating the ends of freshly cut timber with the nonpigmented strain of O. piliferum and spraying logs with Dursban 4E to prevent bark beetles from introducing stain fungi into the sides of logs.