<i>Trichoderma</i> spp. as biocontrol agent against cocoa fruit rot disease: An exploration from Ambon Island, Maluku

Abstract Cocoa fruit rot diseases pose a major threat to global cocoa plantations. The fungus Trichoderma spp. is a potential biocontrol agent against cocoa fruit rot caused by Phytophthora palmivora . This study evaluated Trichoderma spp. isolates sourced from Ambon, Maluku, for biocontrol efficacy. Methodologies employed include both in vitro and in vivo approaches. In vitro evaluations involve antagonism assays which is parasitism, growth inhibition measurements, spore density assessments, and spore viability tests. In vivo experiments gauge the effectiveness of Trichoderma spp. applied as a secondary metabolite solution on infected cocoa fruits. PCR results identified two Trichoderma spp. species: T. viridae 1, T. asperellum 1, and T. asperellum 2. Findings indicated that antagonist fungal colonies completely covered the petri dish since 7 days incubation, with an antagonism percentage of 79.21%, particularly for code T. asperellum 3. Spore density varies among isolates, with T. viridae 1 exhibiting the highest spore density. In vivo results demonstrated that T. asperellum secondary metabolites reduced cocoa fruit rot by 77.33%, with an optimal concentration of 8 ml/l. The study underscores the potential of T. viridae and T. asperellum isolates from Ambon Island, Maluku as effective biocontrol agents against cocoa fruit rot caused by Phytophthora palmivora .