Potentials for Biological Control of Blue Stain on Woods Caused by Ophiostomatoid Fungi

Biological control of blue stain fungi, such as Ophiostoma and Leptographium spp., that reduce the quality of logs and cause economic losses in wood product industry, was carried out in laboratory and field trials by a colorless strain of Ophiostoma quercus, BSFcs-1. Inoculation of pine wood chips with the colorless strain 1 wk before inoculating wild-type strain demonstrated that BSFcs-1 colonized wood chips and excluded blue stain fungi from being established. Efficacy of BSFcs-1 was compared with colorless strain of O. piliferum, which is commercially available under the trade name of Cartapip. Inoculation of pine wood logs with the colorless strain 1 wk before inoculating wild-type strain of blue stain in isolated wood chips, while O. quercus and O. floccosum colonized 0% and 17%, respectively. Simultaneous inoculation of logs with the colorless and wild-type strains resulted in decreased colonization (28%) by BSFcs-1, but increased colonization by O. quercus (185) and O. floccosum (29%). On the other hand, BSFcs-1 and wild-type strain alone colonized 75% and 71%, respectively. Treatment of the surface of log ends with mycelial suspension of BSFcs-1 after cutting also showed good control of blue stain fungi in a pine forest stands.