In vitro evaluation of Trichoderma harzianum strains for the control of Fusarium oxysporum f.sp. cubense

Tricoderma harzianum have been widely used as a biocontrol agent for the suppression of soil-borne pathogens.The objective of this work was to evaluate the potential of T. harzianum strains to control Fusarium oxysporum f.sp.cubense (Foc), a well-known soil-borne pathogen that associated with banana wilt disease.In this study, ten isolates of T. harzianum strain isolated from various regions in Java were evaluated through two in vitro antagonistic approaches, dual culture test and volatile organic compound (VOC) producing test.All strains showed antagonistic activity against Foc according to the dual culture test with various degree of antagonism from efficient antagonism to highly efficient antagonism.Observations after five days, the antagonists overgrew 63% until 88% of medium surface.Similarly, all strains produced toxic volatile metabolites that having significant effects on the growth and development of the Foc.After seven days of exposure with antagonists, the mycelial growth of the test pathogen was inhibited by 24% until 44%.These results indicate that different strains showed variability in the level of antagonism.