Evaluation of in vitro activity of Ganoderma-antagonistic bacteria from peatland under acidic condition

Abstract

As of 2017, 2.05 ha of Indonesia's total oil palm area has been identified as peatlands. A large-scale peatland has caused oil palm commodities to be a global concern because they are thought to have contributed to the increase in greenhouse gas emissions that have triggered climate change. This research is an effort to resolve the main problems in the cultivation of oil palm on peatlands in a more environmentally friendly way. The main obstacle to oil palm cultivation on peatlands is Ganoderma fungi attacks that cause basal stem rot (BSR) disease, where the attack is higher than in mineral soils. Biological control is a prospective alternative way to control BSR disease. However, its development in peatlands is hampered by extremely low peat pH. The possible approach is to utilize appropriate biological control agents for peatlands. This study aimed to examine antagonistic bacteria's from peatlands to control Ganoderma under low pH conditions in vitro. The bacterial isolates from peatlands were tested for antagonism against Ganoderma and tested for their growth ability in 2-7 pH situations. The results showed that from the West Kalimantan peatlands, Ganoderma-antagonistic bacteria grew at pH 2-4, even though the growth rate had decreased significantly. The isolates were E4B6, E2B12, E2B13, B3B11, and E2B3. These results indicate that these bacteria can be used in controlling oil palm BSR disease caused by Ganoderma in peatlands.