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Aim: This study was undertaken to isolate Bacillus subtilis strains with biological activity against soil‐borne phytopathogenic fungi from the avocado rhizoplane.

Methods and Results: A collection of 905 bacterial isolates obtained from the rhizoplane of healthy avocado trees, contains 277 gram‐positive isolates. From these gram‐positive isolates, four strains, PCL1605, PCL1608, PCL1610 and PCL1612, identified as B. subtilis, were selected on the basis of their antifungal activity against diverse soil‐borne phytopathogenic fungi. Analysis of the antifungal compounds involved in their antagonistic activity showed that these strains produced hydrolytic enzymes such as glucanases or proteases and the antibiotic lipopeptides surfactin, fengycin, and/or iturin A. In biocontrol trials using the pathosystems tomato/Fusarium oxysporum f.sp. radicis‐lycopersici and avocado/Rosellinia necatrix, two B …