<![CDATA[Mulawarman, M., Aziz, H. A., Rizky, D., Tampubolon, D. E., & Ramadhani, C.D. (2025). The Potential of the Biological Agent Trichoderma spp. in Controlling Ganoderma boninense, the Cause of Basal Stem Rot in Oil Palm. In: Herlinda S et al. (Eds), Prosiding Seminar Nasional Lahan Suboptimal ke-13 Tahun 2025, Palembang 30 September. Pp. 274-282. Palembang: Penerbit & Percetakan Universitas Sriwijaya (UNSRI).Ganoderma boninense is the main cause of basal stem rot disease in oil palm plants. Controlling this disease using biological control agents, such as Trichoderma, is an environmentally friendly and sustainable solution. This study aimed to evaluate the ability of three Trichoderma isolates, namely Trichoderma harzianum, Trichoderma asperellum, and Trichoderma viride, to inhibit the growth of G. boninense in vitro and test them in plant conditions. This research was conducted at the PT. Sampoerna Agro Laboratory from March 2018 to April 2018 and also at the Nematology Laboratory from March 2019 to May 2019. This study used a Completely Randomized Design method, which included: (1) isolating and growing G. boninense on Ganoderma Selective Agar medium, (2) conducting in vitro antagonism tests using a double culture technique on the three Trichoderma isolates, (3) calculating the percentage of pathogen growth reduction, and (4) conducting in planta tests using oil palm leaf sticks inoculated with G. boninense. The in vitro test results showed that T. harzianum and Trichoderma viride isolates were able to inhibit the growth of G. boninense at a significant and equal level, while Trichoderma asperellum showed lower ability. In a two-month in planta test, oil palm plants treated with sticks inoculated with G. boninense and the biological agent Trichoderma showed good growth without any symptoms of basal stem rot. Based on these results, Trichoderma harzianum and Trichoderma viride isolates have the potential to be effective biological control agents for controlling basal stem rot in oil palm plants.]]>
