Antagonistic Effects of Bacillus Species in Biocontrol of Tomato Fusarium Wilt

Fusarium solani is the causative organism of Fusarium wilt of tomato (Lycopersicon esculentum Mill). Four Bacillus spp identified as B. amyloliquefaciens, B. cereus, B. pumilus and B. subtilis were tested for biocontrol activities in vitro as zone of inhibition and in vivo as percent disease control and disease incidence. The result from in vitro analysis showed that B. amyloliquefaciens inhibited the growth of F. solani the most by 95.2% while B. cereus had the highest growth of F. solani and inhibition of 55.7%. B pumilus and B. subtilis showed inhibition of 70.46% and 82.1% respectively and were significantly lower (p=0.05) than the control with 100% F. solani growth. In vivo , B. cereus had the least disease incidence and highest percent disease control (18.75% and 81.2%). This was significantly different from the control (100% and 0%), B. amyloliquefaciens (25% and 75%), B. pumilus (37.5% and 62.5%) and B. subtilis (37.5% and 62.5%). Also, growth parameters like shoot and root length from treatment with B. cereus (38 mm ±1.47 and 31 mm ±1.22) were significantly longer (p=0.05) compared to the control. This result shows that these four Bacillus spp are very effective biocontrol agents and should be harnessed for further biocontrol applications.