Screening of biological control agent fungi against peanut stem rot (Sclerotium rolfsii Sacc.) in the peatlands of Kuala Pesisir Nagan Raya, Aceh, Indonesia

Peanut stem rot disease caused by Sclerotium rolfsii Sacc. is a problem that needs special attention in peatlands. Peatlands that are wet, acidic and contain high organic matter should be able to support and increase the pathogenicity of S. rolfsii. However, this is not the case for the peatlands of Kuala Pesisir Nagan Raya, have been other components cause these pathogens not to develop. Here we try to examine the biological elements, namely the existence of biological control agents from the fungal group, which generally like the same environmental conditions as pathogens. This study aims to obtain peat soil antagonistic fungi that can control S. rolfsii. This research was conducted in Kuala Pesisir, Nagan Raya Regency, Aceh, Indonesia. Research activities include isolation, morphological identification, pathogenicity testing, antagonist testing, and molecular identification. The results obtained 46 fungal colonies from three sources, namely weed rhizosphere around peanut farming, peanut rhizosphere, and groundnut roots. The results showed that there were antagonistic fungi that could suppress S. rolfsii, namely Trichoderma asperellum.