Abstract
We investigated the light conditions during the decaying procedure with the laboratory test designated in the Japanese Industrial Standard (JIS) K 1571-2004. Experiments were performed using the sapwood of Japanese cedar (Cryptomeria japonica D. Don). The results obtained were as follows :
(1) The mass losses of the untreated wood specimens depended on the light irradiation time during the incubation of Fomitopsis palustris (Berk. et Curt.) Gilbn. & Ryv.). Even greater mass losses occurred after 10 days of culturing under light irradiation and the mass lost about 60% (maximum value) in the 60 days of culturing.
(2) The mass losses were great when culturing was performed using 900ml mayonnaise bottles with screw caps equipped with the range 25-40mm inside diameter of glass tubes as aeration conditions during the incubation of Trametes versicolor (L. : Fr. ) Pilát. Even greater mass losses occurred after 45 days of culturing under the light-shield condition. Also, the wood decay was inhibited by the light irradiation and the irradiation acted to shorten the periods of the mass losses during the incubation of the fungus.
(3) These results may extensively influence the evaluation of the preserving performance of wood preservatives using the laboratory decay test designated in JIS K 1571-2004.
