The Potential of Palm Oil Mill Effluents and Bacillus amyloliquefaciens EB13 in Reducing of Ganoderma boninense Disease in Oil Palm

Abstract

Indonesia is the largest palm oil producing country in the world. Ganoderma boninese disease is the most destructive that cause limiting factor in production of oil palm. It is a crucial to discover an effective management strategy for a serious threat of basal stem rot disease of G. boninense in oil palm. The objective of this research was to assess the possible use of palm oil mill effluents (POME) and Bacillus amyloliquefaciens EB13 in reducing of oil palm disease caused by G. boinense. In greenhouse experiment has shown that POME and B. amyloliquefaciens EB13 significantly reduced disease index (DI) of oil palm disease from 4.0 to 2.3 and from 4 to 1.8 respectively. Biocontrol efficacy of B.amyloliquefacient and POME were 70.9 and 70.4 respectively. The addition of POME into soil has significantly reduced population of fungy from 40.0 to 1.8 x 104 CFU g−1 fresh soil, and the addition of B. amyloliquefaciens reduced population of fungy from 40.0 to 2.3 x104 CFU g−1 fresh soil. Amount of bacteria population increased from 13.8 to 19.0 x 106 CFU g−1 fresh soil by adition of POME, even the increasing was not significant. While addition of B. amyloliquefaciens significantly increased bacteria population from 13.8 to 56.8 x106 CFU g−1 fresh soil. Laccase activity in soil inoculated only with G. boninense would significantly highest compared with combined treatment of POME and G. boninenese, and the combined treatment of B. amyloliquefaciens and G. boninense, their activities were 2991.2 UmL−1, 1140.6 UmL−1, and 609,6 UmL−1 respectively. Lignin peroxidase activity in soil inoculated only with G. boninense and soil with combined treatment of POME and G.boninense higher than the combined treatment of soil with B. amyloliquefaciens and G.boninense, their activities were 666.4 UmL−1, 655.3 UmL−1, and 492.4 UmL−1 respectively. The highest activity of mangan peroxidase was detected in soil inoculated only with G. boninense compared with combined treatment of POME and G. boninense, and the combined treatment of B. amyloliquefaciens and POME, although the differences were not significant, their activities were 202.3 UmL−1, 146.3 UmL−1, and 148.9 UmL−1.