Abstract

The biocontrol potential of Bacillus subtilis S499 was evaluated on tomato in open field sites in low altitude area of the plain of Imbo in Burundi. This strain was tested in order to reduce the impact of an important fungal disease giving rise to large losses in local plantings. The causing pathogen was isolated from diseased leaves at different locations in the fields and identified as Fusariummost probably related to the semitectum species according to the fermentation profile, morphology and gene homology. Results of assays performed in two successive years on the same site indicated that bacterial treatment on seeds significantly increased growth and fruit yield of tomato plants and also provided a high level of protection against the disease caused by this Fusariumpathogen. This is the first reported study on this disease and based on the data collected, B. subtilis S499 may represent an effective solution as biocontrol agent where other chemical options have failed.

Key words: Bacillus subtilis, biocontrol, Fusarium disease, tomato plants.