Evaluation of the Antagonistic Potential of Trichoderma atroviride and Trichoderma harzianum against Fusarium Wilt of Banana (FWB), under in vitro conditions

Banana (Musa spp.) is the most valued and traded fruit worldwide and is a major food security crop and source of incomes for millions of people in the global south. Fusarium oxysporum f.sp. cubense (Foc), the causal agent of Fusarium wilt of banana (FWB) is the most prominent threat and devastating disease of banana, posing a serious threat to global banana trade. Trichoderma species are renowned biocontrol agents of many phytopathogens, showing encouraging results in vitro. This study was conducted to assess the antagonistic and biocontrol potentials and mechanisms of mycoparasitism of Trichoderma atroviride and Trichoderma harzianum against Foc. The Dual culture technique and culture filtrates were used to evaluate the efficacy of both Trichoderma species against Foc. Mycoparasitism of Trichoderma against Foc were determined by observing a mixture of both fungal species taken from a 14-days old dual culture. The mixture was observed under a simple light microscope. The means of both in vitro tests was analysed in GenStat software, 14th edition (p<0.05). Dual culture and culture filtrates of T. atroviride inhibited the mycelial growth of Foc by 60.56% and 65.33%, respectively. Consequently, T. harzianum exhibited 64.21% and 61.75% inhibition of Foc. As per Bell’s Degree of Antagonism, both Trichoderma species were highly antagonistic against Foc after seven days. Both species demonstrated coiling, lysis, penetration and winding as mycoparasitism. The results show that T. atroviride is a promising biocontrol agent and can be used alongside T. harzianum in the management of Fusarium wilt of banana.