Isolation of actinomycetes from rhizosphere of oil palm (Elaeis guineensis Jacq.) for antagonism against Ganoderma boninense

This study reports the isolation and screening of actinomycetes from the rhizosphere of oil palm (Elaeis guineensis Jacq.) for antagonism against Ganoderma boninense, the causal agent of basal stem rot disease of oil palm. A total of 600 isolates of spore producing and fast growing actinomycetes with different morphology were tested for their inhibitory effects on G. boninense mycelial growth on dual culture plates. About 13.5% of the isolates showed Percentage Inhibition of Radial Growth (PIRG) of more than 80% with 21 isolates exhibited observable abnormal growth of G. boninense. These 21 isolates were further tested using their culture filtrates in the form of liquid or powder (freeze-dried) for their effect towards G. boninense growth. Four isolates: AGA 043, AGA 048, AGA 347 and AGA 506 were highlighted for their ability to inhibit and exhibit potential metabolites against G. boninense. This study identified actinomycete strains with the ability to affect and inhibit the growth of G. boninense