The Effect of Application Endophytic Fungus Trichoderma spp. and Fusarium spp. to Control Bacterial Wilt in Chilli Pepper

Endophytic fungi have an ability on producing secondary metabolites that promote plant growth, increase plant resistance to biotic and abiotic stresses, and enhance growth. Plant disease is an important biotic stress that need to be controlled. Potential use of endophytic fungi to induce resistance against bacterial wilt disease in chilli pepper (Capsicum annuum L.) caused by Ralstonia solanacearum has not been widely reported. This research was aimed to determine the potential of endophytic fungi in suppressing development of bacterial wilt disease in chili. The study was conducted using three endophytic fungi such as Fusarium solani f.sp. phaseoli isolates AC-2.13 and AC-3.18, and Trichoderma asperellum AC-4.4. This tests used nine treatments, i.e three single treatments, four combination treatments, streptomycin, and control. The results showed that application of endophytic fungi F. solani f.sp. phaseoli and T. asperellum either in single or combination treatments reduced development of bacterial wilt in chili with inhibition rate of 12.5% to 50%. Applications of combined endophytic fungi were not always inhibiting development of bacterial wilt in chili. The ability to suppress disease development by endophytic fungi was not always followed by its ability to increase crop yield. F. solani f.sp. phaseoli isolate AC-44 have highest potential of endophytic fungi in controlling R. solanacearum. In the biochemical evaluation, F. solani f.sp. phaseoli showed increasing of several compounds activity in chili such as total phenol, peroxidase (PO), polyphenol oxidase (PPO), β-glucanase, and phenylalanine aminaliase (PAL).