Abstract:
A study was conducted to determine the inhibitory effect of Bacillus subtilis and B. pumilus
against the causal pathogen of late leafspot (Cercosporidium personatum) In-vitro.
Infected leaf samples were collected from peanut fields in Burgos, La Union. Isolation of
the pathogen from the infected leaves was done at the Plant Pathology Laboratory, College of
Agriculture, Benguet State University, La Trinidad, Benguet. The pathogen and the biocontrol
agents were prepared in ready for the bioassay. Inhibition zones produced by the Bacillus subtilis
and B. pumilus against Cercosporidium personatum were measured. Results showed that B.
subtilis isolates (PCN 2011 – 005, PCN 2011 – 002, St 2011 – 001) and B. pumilus (131) inhibited
the growth of C. personatum but not significantly different with the negative control. Nevertheless,
the presence of the inhibition zone, regardless of size, is an adequate indication of their potential
ability to control the pathogen.
It is recommended that another study shall be conducted identifying and using the
metabolites of the same biological control agents instead of the live specimens used. Further
studies shall be done using potted plants then to the actual field condition.
