Effectiveness and synergistic of endophytic bacteria in inhibiting the development of cocoa black pod rot disease (Phytophthora palmivora bult.).

The utilization of endophytic bacteria is one of the solutions to control the cocoa black pod rot disease (Phytophthora palmivora Bult) which is environmentally friendly without toxic residues. This study aimed to examine the effectiveness and synergism of several endophytic bacteria from healthy cocoa plants toward inhibit the development of cocoa black pod rot disease. The study used a Randomized Block Design consisting of 11 treatments with a single and mixed application of endophytic bacterial suspension on cocoa pods on trees. Two weeks after application, the cocoa pod was picked from the tree and inoculated with P. palmivora PPKT01 in the laboratory. The inoculated pods were incubated in a plastic box lined with wet tissues to keep the box moist. Disease severity was observed at 3, 5 and 7 days after inoculation. To calculate the AUDPC value, disease suppression index, and synergism between isolates used the results of disease severity observation. The endophytic bacteria inhibited the development of the disease, with effectiveness between 27.31%-55.04%. The mixed treatment of endophytic bacteria Pseudomonas aeruginosa 5BRB3 and Bacillus subtilis 3BAE strains had the lowest disease severity and AUDPC values, making it the most effective and synergistic in inhibiting pod rot disease with a disease suppression index of 55.04%. [ABSTRACT FROM AUTHOR]