Enhancing Freesia (Freesia armstrongii) Growth and Yield through Trichoderma-Mediated Biocontrol of Fusarium Wilt

The current research explored the biocontrol ability of two strains of Trichoderma fungi on infected Freesia corm by Fusarium disease. Enhancements in plant growth and performance were evaluated in response to the Trichoderma fungi in laboratory and greenhouse conditions. Laboratory experiments included five Trichoderma strains, i.e., T1, T20, and Th4, related to T. harzianum species, T2 related to T. atroviride species, and Tvi related to T. virens species. A dual culture test and investigation of the inhibition and colonization rate were carried out with 11 treatments in three replications. Results revealed that strains T1 and T2 completely covered the pathogen in 96 h of culture by 70.02% and 68.98% and successfully inhibited the colonization of the disease agent by 84.53% and 82.72%, respectively, compared to the other strains. Then, a greenhouse experiment was performed with eight treatments, using suspensions of Trichoderma strains separately or combined with the presence of Fusarium fungus isolate on Freesia cultivation. The results showed that the strains at different levels were able to increase the growth and yield of Freesia plants and control Fusarium disease. In general, the T2 strain was more effective in increasing plant growth and flower stem height in Freesia. The T1 strain specifically improved the corm diameter. Both T1 and T2 strains demonstrated effectiveness in controlling and reducing the severity of Fusarium disease and enhancing the growth quality of Freesia.