Tomato Fusarium wilt is one of the crucial diseases threatening tomato production worldwide. In this study, the in vitro antagonistic potential of four Trichoderma species (Trichoderma koningii K-19, T. harzianum K-20, T. brevicompactum K-26, and T. atroviride TR-1) was evaluated using dual culture assays, volatile organic compound (VOC) bioassays, and cell-free culture filtrate (CFCF) tests. All tested isolates significantly inhibited pathogen mycelial growth in different bioassays. Among them, T. koningii K-19 consistently exhibited the strongest antagonistic activity, achieving inhibition rates of 70.37% in dual culture assays, 45.48% in sealed plate assays, and 43.10% in culture filtrate assays. In comparison, T. harzianum K-20, T. atroviride TR-1, and T. brevicompactum K-26 inhibited pathogen growth by 65.31%, 60.68%, and 66.40% in dual culture assays; 24.29%, 32.38%, and 31.43% in sealed plate assays; and 34.52%, 28.81%, and 35.95% in culture filtrate assays, respectively. These findings indicate that T. koningii K-19 suppresses the Fusarium wilt pathogen through multiple antagonistic mechanisms, such as competition, antibiosis, and volatile antifungal compounds. These findings demonstrate the potential of T. koningii K-19 as a promising biocontrol agent against tomato Fusarium wilt, requiring evaluation of its effectiveness in field trials in further studies.
Aydın Atakan (Thu,) studied this question.