PROBLEM TO BE SOLVED: To provide a control method of a raw timber decay disease by promoting growth of spontaneous Trichoderma bacteria without using special chemicals.SOLUTION: A control method of a raw timber material decay disease is provided by infecting Trichoderma bacteria which is a spontaneous natural enemy bacteria to basidiomycetes of a diseased part of a tree in which infection of a wood decay disease is progressing. A treatment of scraping off at least a portion of the part of the tree infected by the basidiomycetes is performed, and then it is covered by a member having breathability and optical transparency.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】特別な薬剤等を使用せずに、自然発生のトリコデルマ属菌の生育を促すことによって、生立木腐朽病害の防除方法を提供する。【解決手段】木材腐朽病の感染が進行している樹木の罹病部の担子菌類等に対する、自然発生の天敵菌であるトリコデルマ属菌を感染させることによる生立木材質腐朽病害防除方法であって、担子菌類が感染している樹木の部位の少なくとも一部を削り取る処置を施したのち、通気性と光透過性を有する部材でカバーする。【選択図】図1