Biological control of arbuscular mycorrhizal fungi and Trichoderma harzianum against Fusarium oxysporum and Verticillium dahliae induced wilt in tomato plants

Abstract Background Arbuscular mycorrhizal fungi (AMF) and Trichoderma harzianum are effective bioagents against Fusarium oxysporum and Verticillium dahliae in tomato plants. The objective of the research was to evaluate the in vivo antagonistic activity of AMF and T. harzianum against Verticillium and Fusarium wilt by enhancing the growth and resistance of tomato plants. A completely randomized experimental design was used, consisting of twelve treatments with nine replicates for each treatment. The treatments included combinations of AMF and T. harzianum inoculation, infection or non-infection by F. oxysporum and V. dahliae, while also considering individual and combined treatments. Mycorrhization rates, growth parameters, disease severity, disease progression, and the impact on disease mitigation were evaluated. Results The study revealed the superiority of AMF over T. harzianum , resulting in a significant enhancement in the overall extent of mycorrhizal colonization in tomato plants co-inoculated with T. harzianum . Moreover, AMF treatments and the AMF + T. harzianum consortium contributed to the improvement in growth among all plants infected with V. dahliae and F. oxysporum . Both AMF and T. harzianum significantly reduced the progression of Fusarium wilt, resulting in reductions of 45.14 and 44.91%, respectively, than the untreated plants infected with F. oxysporum (initial disease severity of 75.54%). T. harzianum demonstrated greater efficacy in reducing V. dahliae infection, with a reduction of 34.45% compared to 28.26% for AMF, starting from an initial disease severity of 69.85%. Thus, T. harzianum demonstrated greater effectiveness in controlling disease, particularly Verticillium wilt. Conclusion The target application of disease control methods in tomato plants revealed the effectiveness of both AMF and T. harzianum in mitigating Fusarium wilt. Furthermore, T. harzianum demonstrated a higher level of effectiveness against Verticillium wilt. These findings emphasize the potential of AMF and T. harzianum as sustainable alternatives in agriculture, providing a viable option to decrease dependence on fungicides.