Oei (2003) reported that substrate having high quality lignin and cellulose contents takes a longer time to start pinning and fruit body formation. Similarly in mycelia extension, maize stalk showed rapid colonization, fast primordial initiation and earliest harvest day with addition of rice bran. In the present study, the fruiting bodies appeared 32-44 days after inoculation of spawn. These findings are in conformity with the results of Quimio et al., (1999) who reported that formation of fruiting bodies was 3-4 weeks after inoculation of spawn. Similarly, Tan (1981) reported that P. ostreatus and other species on cotton waste took 2-3 weeks for fruit body formation after spawn running. According to Baysal et al., (2003), the fastest mycelial growth, pin head formation and fruit body formation were recorded with the supplementation of 20% rice husk.