Trichoderma asperellum as a Promising Biocontrol Agent Against Black Rot of Malaysian MD2 Pineapple

Black rot, a significant postharvest disease of pineapple (Ananas comosus) var. MD2, is caused by the fungal pathogen Thielaviopsis paradoxa. This disease severely compromises fruit quality during transportation and storage by inducing tissue disintegration, watery rot, and extensive damage, thereby reducing shelf life. In this study, 103 fungal isolates, obtained from healthy pineapple leaves and fruits, were screened for antagonistic activity against T. paradoxa using a dual culture assay. Among the tested isolates, Trichoderma asperellum, identified via ITS rRNA gene sequencing, exhibited the highest antagonistic effect with a percentage inhibition of radial growth of 98%. Further in vivo assays assessing disease severity and progression on MD2 pineapple fruits demonstrated that the application of T. asperellum spore suspension (109 CFU mL-¹), four hours prior to pathogen inoculation, effectively suppressed black rot development. These results demonstrate that preventive application of T. asperellum can significantly reduce black rot severity, offering a viable alternative to synthetic fungicides in postharvest management.