Bacterial wilt disease caused by Ralstonia solanacearum Smith. with yield losses reaching 50–100% in potato plants. The application of chemical pesticides can indeed reduce the intensity of the disease quickly but can cause losses in the form of environmental pollution and can kill beneficial microorganisms in the soil. An alternative control is needed with the concept of Integrated Pest Management, one of which is using the biological agent Trichoderma koningii Oudem. This study aims to determine the effect of the application of T. koningii to reduce the intensity of bacterial wilt ( R. solanacearum ) on potatoes ( Solanum tuberosum L.). The research was conducted from November 2022-February 2023 at the UPTD Potato Seed Center, Food Crops and Horticulture Service, West Java Province. The study was conducted using the experimental method of randomized block design with 5 treatments and 5 repetitions. The treatment consists of: Application of T. koningii with a concentration of 5 grams/plant, 10 grams/plant, 15 grams/plant, 20 grams/plant and without application. The results showed that the use of the application of T. koningii had the best effect on suppressing the intensity of the disease of R. solanacearum with a concentration of 20 grams/plant which had the best effect by suppressing the disease intensity of 89%.