Since inhibition of
A. niger by selected PGPR isolates was clearly observed in a plate as-say, only A. niger was used in this research for further elucidating the
biocontrol efficiency of selected PGPR isolates. It has been reported
that biocontrol rhizobacteria Bacillus cereus, B. subtilis, B. circulans, B.
licheniformis , B. stearothermophilus, and Chromobacterum violaceum
were able to colonize the sorghum root (in vitro ) in a range of 4–9
log cfu per cm root, and were able to inhibit the growth of Fusarium