This is a hands-on practical guide to the use of Trichoderma as a biocontrol, as part of sustainable disease control measures for Ganoderma disease in oil palm plantations. The manual provides background information on Ganoderma (basal stem rot), the most devastating disease of oil palm in Southeast Asia, as well as on the benefits of Trichoderma fungi in safe guarding yields. The disease is caused by soil-borne fungi, Ganoderma spp, which are found in West Africa and South America, as well as Southeast Asia. Practical information is given on: the use of Trichoderma to manage Ganoderma for research and commercial use health and safety considerations in the laboratory, nursery and field in vitro multiplication of Trichoderma starting from media preparation and culture Ganoderma pathogenicity testing Trichoderma in vitro antagonism screening of Ganoderma Trichoderma screening to protect seedlings scoring Ganoderma response to Trichoderma in selecting aggressive Trichoderma isolates commercial use and application in oil palm plantations This is an invaluable manual for oil palm growers, estate/plantation managers, pathologists and breeders and research institutes across the world (especially tropical zones). It is also useful for those starting a career in oil palm plant protection, and as a reference guide for managers and for training purposes.