Shiitake (Lentinula edodes) cultivation in sawdust media consisting of kunugi (Quercus acutissima) mixed with sugi (Cryptomeria japonica): optimization of gaseous phase rate in media by three-phase-structure analysis

The effects of the gaseous phase rate of kunugi (Quercus acutissima) sawdust media mixed with sugi (Cryptomeria japonica) determined by a three-phase-structure analysis of the fruiting body yields of shiitake were investigated. The fruiting body yield on kunugi media was significantly lower than that on commercially available hardwood-sawdust-mixture (HSM) media with 64 % water content. Three-phase-structure analysis showed that the gaseous phase rate in kunugi media was lower than that in HSM media. When the gaseous phase rate in kunugi media was increased to the level in HSM media by decreasing the water content to 56 %, the fruiting body yield on kunugi media also increased. These results suggested that kunugi sawdust could be used for shiitake cultivation if the gaseous phase rate in the media was optimized. Because sugi has a lower specific gravity and higher porosity than kunugi, mixing sugi sawdust up to 30 % with kunugi media caused an increase in the gaseous phase rate, and the fruiting body yield reached the same level as that in HSM media. These results suggested that kunugi media could be used for shiitake cultivation by mixing with sugi sawdust.