Accepted 31st November, 2014
Studies on the potential of three Trichoderma spp. (ghanense, longibrachiatrud and asperellum) as biological control agents of rice blast (Magnaporthe grisea) pathogen populations were undertaken in Ibadan, southwest Nigeria during 2009 wet season. Two blast susceptible varieties of Rice seed used in the study were selected because they are widely cultivated by farmers in southwest Nigeria. Rapid colonization growth of the Trichoderma broth were observed at four different dilutions(1:1,1:2,1:3,1:4) at lowest concentration of 20ml/250ml of water the inhibition of Magnaporthe grisea was significant on the field and in the laboratory. The results of all these experiments showed that each of the Trichoderma species is a potential biological control agent of rice blast. However, the best result was obtained when sprayed before blast infection (that is, applied 21 days after planting) and at the initial stages of blast manifestation.
Keywords: Three Trichoderma spp. ghanense, longibrachiatrud and asperellum, biological control agents, rice blast,