Efficacies of an insecticide and a fungicide for preventing blue-stain of Japanese red pine logs
H Taniuchi, T Koiwa, H Masuya, S Doi
We examined blue-stain fungi on Japanese red pine at 3 forests and 2 saw mills in Iwate Prefecture, Japan. The isolated ophiostomatoid fungi were Leptographium sp and Ophiostoma sp. There were 3 routes of the blue-stain; fungal growth from the spore or hypha stuck on the cross cut surfaces, fungal spread through the inner bark by bark beetles and fungal invasion around whorled knot. The larger extensions of blue-stain in summer and spring seasons were mainly caused from infestations of bark beetles. Efficacies of an insecticide and a fungicide for preventing blue-stain were also evaluated. For preventing blue-stain through the year, it was required to treat logs with the insecticide against bark beetle attacks and with the fungicide to inhibit fungal growth on the cross cut surface.
Keywords: blue-stain, Japanese red pine, Ophiostoma, Leptographium, bark beetle, insecticide, fungicide