Rice husk gave the fastest mycelial growth rate; however,
this did not correspond with yield, indicating that
mycelial growth and yield of mushrooms have different
requirements [6]. Also, this substrate is very susceptible
to drying, which affected sporophore formation [8].
Given the physical nature and high porosity of the rice
husk, and also the fact that it dries up very fast, it will be
advisable to use it as an additive to sawdust for use as
mushroom substrate. In an experiment in which 2% (w/
w) of rice husk was added to composted sawdust, there
was an 11% increase in mushroom yield (J. Cleland-
Okine et al. unpublished).