Abstract
To establish methods of on-site preservative treatment of decayed wood, we investigated the effects of a wood preservative used as a surface treatment on slightly-decayed wood caused by Serpula lacrymans using Yezo spruce (Picea jezoensis) sapwood specimens measuring 2(T)×2(R)×4(L) cm. After 2-8 weeks of exposure to S. lacrymans, fungal mycelium was removed from one specimen group ; and fungus was left on the surface of the other specimen group. Both groups were then dipped in SF1083 (an oil-borne wood preservative containing a combination of organic iodine and an azole compound), and the subsequent efficacy of the surface treatment against S. lacrymans was evaluated by mass loss of the specimens. The mass loss in specimens with mycelium either removed or not removed was strongly suppressed by the surface treatment. In a second trial, 2 specimens of Yezo spruce sapwood measuring 2(T)×2(R)×1(L) cm were exposed to S. lacrymans in a culture bottle for 2 weeks. One specimen had SF1083 dripped on it, while the other was left untreated. The specimens were then exposed to S. lacrymans for a further 10 weeks, after which mass-loss percentages since treatment were measured. There was no mass loss in the specimens treated with SF1083, which was also suppressed in the specimens that were left untreated. From these results, it was determined that surface treatment of wood with SF1083 in the early stages of decay due to S. lacrymans suppressed progression of the decay on both treated portions and areas surrounding them.
