A formulation containing conidia of non-toxigenic strains of fungi is a useful biocontrol agent for preventing toxin contamination in agricultural commodities, especially those for human and animal consumption such as peanuts, corn, cotton and tree nuts. The formulation of the invention is a water dispersible granule formulation suitable for spraying and includes non-toxigenic and/or non-aflatoxigenic Aspergillus flavus strains capable of inhibiting growth of fungi which produce aflatoxin and further capable of suppressing production of aflatoxin by the toxigenic fungi. A method of preparing the formulation is shown.
