ABSTRACT

Rhizobacteria have been proved to have potential for biocontrol of fungal phytopathogens and have been successfully applied in the field to a variety of crops. However, diseases caused by Phomopsis longicolla on soybean have been mainly controlled by agricultural or chemical techniques. The objective of this study was to evaluate the in vitro control of rhizobacteria on P. longicolla through their ability to inhibit the growth of P. longicolla on agar plates and disease caused by P. longicolla on soybean seeds. The results showed that the GTC 5.3.84 rhizobacterial isolate was able to inhibit 31% of the growth of P. longicolla GTC 2.5.1 on the agar plate. The GTC 5.3.84 isolate had no effect on germination rate and was able to completely inhibit the disease caused by P. longicolla GTC 2.5.1 on soybean seeds. This result was very clear evidence for the potential application of indigenous rhizobacteria in the control of diseases caused by P. longicolla in soybean. Further studies need to be continued to exploit the efficiency of the GTC 5.3.84 isolate as well as the potential of other indigenous rhizobacteria in the control of P. longicolla disease in soybean.

Keywords: Antagonistic; biocontrol; Phomopsis longicolla; rhizobacteria; soybean.