Endophytic fungi associated with cacao branch and their potential for biocontrol vascular streak dieback disease on cacao seedling

Abstract

Endophytic fungi are one of the agents to control phytopathogen both bacterial or fungi including dieback disease on cacao such as Vascular Streak Dieback (VSD). Ten fungal isolates that associated with a healthy branch of VSD resistant clone was applied to cacao seedling, the fungi were a Curvularia-like colony, a Fusarium-like colony, a Geotrichum-like colony, an Aspergillus-like colony, a Gliocladium-like colony, a Colletotrichum-like colony and four isolates indicates as mycelia sterilia fungi. Those fungi were applied at 2.5-old months cacao seedling of moderate to susceptible clone against VSD, and 30 days after inoculation of those fungi, the seedling was applied with a bunch of mycelia emerged from infected branch that mix with water using mixer appliance and then the seedling was exposed at open area surrounded by infested cacao tree. The disease incidence was recorded started at 30 and then 60, 90 and 120 days after inoculation of the pathogen and exposed. The result of study shows that the disease appeared increasing gradually and 120 days fungus Curvularia-like colony exhibited lower incidence followed by Copper fungicide, Mycelia sterilia 1, Gliocladium-like colony, Fusarium-like colony, Geotrichum-like colony, Mycelia sterilia 3, Colletotrichum-like colony, Aspergillus-like colony, control (no application), Mycelia sterilia 2, Mycelia sterilia 4 with percentage of 3.0, 8.3, 9.5, 11.3, 15.8, 18.0, 19.0, 19.3, 21.3, 26.5, 30.5, respectively. The result indicates that some fungi associated with VSD resistant clone were able to prevent VSD to develop and causing symptoms.