Potential of Trichoderma as an active ingredient of biofungicide to control stem rot disease in citrus plants

The negative impacts of chemical pesticides need to be overcome by using eco-friendly alternatives, such as biological control agents in bio fungicides. This study aims to determine the ability of several Trichoderma isolates as active bio fungicide ingredients for controlling Botryodiplodia sp. which causes stem rot disease. The research was conducted in three stages. The first stage tested the efficacy of the Trichoderma isolate Tc-Jrr-02 against stem rot disease under field conditions, compared with a copper sulfate fungicide (wettable powder in liquid paste form) as a control. The second stage assessed the antagonistic activity of five Trichoderma isolates against Botryodiplodia sp., and vice versa, in vitro. Field data were analyzed using a T-test, while in vitro data were analyzed using ANOVA followed by the HSD test at the 5% significance level. The final stage identified all Trichoderma isolates through molecular marker analysis and constructed their phylogenetic relationships. The results showed that Trichoderma sp. provided significantly higher control efficacy than copper sulfate, with recovery scores of 5.56 ± 0.27 and 4.10 ± 0.32 (p < 0.01). All isolates inhibited pathogen growth by 69.26–75.19% and were identified as Trichoderma asperellum, indicating strong potential as effective and sustainable bio fungicide agents.