There was no mycelial growth of the test fungi regardless of chitosan concentrations used when either
L. procerum or S. sapinea was simultaneously inoculated with T. harzianum. However, the dose–response
of chitosan or chitosan oligomer on the test fungi was apparent when T. harzianum was not simultaneously
inoculated with test fungus but introduced later. There was a greater growth reduction at higher
concentrations (0.075–0.1% v/v) of chitosan, and overall chitosan oligomer was more effective than chitosan
aqueous solution