Burkholderia isolates from a sand dune leaf litter display biocontrol activity against the bole rot disease of Agave sisalana

•A novel phylogenetic clade of Burkhloderia was isolated from leaf litter.•Burkholderia inhibited A. niger mycelial growth and conidia germination in vitro.•The isolates varied in vitro, but consistently controlled bole rot in the field.•Disease severity was reduced by 54–77% in two independent field experiments.•Formulations with metabolites and inactivated Burkholderia cells will be developed.