The mean mycelial colonisation rate of P. pulmonarius using 10 mL of liquid spawn applied onto sterile rubber wood sawdust in plastic bags of 21 cm height was compared to grain spawn (10 g) as inoculum and shown in Table 2. The present work showed that fruiting substrate consisting of rubber wood sawdust supplemented with rice bran promoted thick and significantly (p < 0.05) rapid mycelial growth of P. pulmonarius liquid spawn (7.7 ± 0.2 mm day−1) compared to grain spawn (5.2 ± 1.0 mm day−1). Therefore, the time taken to complete spawn run was shorter when using liquid spawn that took 30 days after inoculation compared to the traditional grain spawn that took 40 days.