Evaluation of Antagonistic Activity of Trichoderma harzianum Against Various Pathogenic Fungi Infecting Dragon Fruit Stem

Abstract

Dragon fruit stem is prone to the infection of various pathogenic fungi and Trichoderma harzianum had been reported as an effective biological control agent against plant pathogenic fungi. This study was aimed to evaluate the ability of T. harzianum in controlling various pathogenic fungi infecting dragon fruit stem. This study was conducted using Completely Randomized Design (CRD) with three replicates. Pathogenic fungi was isolated from infected dragon fruit stem, then characterized morphologically to identify the species of those pathogenic fungi. The isolated fungi were subjected to in-vitro and in-planta antagonistic assay containing T. harzianum culture. The resulted growth inhibition in each fungal isolate was observed for a week by comparing the diameter of pathogenic fungi. Based on morphological characteristics, the dragon fruit stem was predicted to be infected by several pathogenic fungi, such as Phytium sp. (isolate A), Fusarium sp. (isolate B), Alternaria sp. (isolate C) and Rhizoctonia sp. (isolate D). Result of in-vitro antagonistic assay showed that T. harzianum conferred different suppression efficacy against all isolated pathogenic fungi ranging from 59-66%. Moreover, application of T. harzianum in-planta had resulted promising fungal growth inhibition up to 50% against all pathogenic fungi.