Compositions and methods are provided for a combination of a new strain of
Bacillus amyloliquefaciens RTI301 and a new strain of
Bacillus subtilis RTI477, the combination having
growth promoting activity and activity against
plant pathogens. The compositions containing the RTI301 and RTI477 strains are useful for benefiting
plant growth and / or conferring protection against a pathogenic infection when applied to
plant roots, seeds,
callus tissue, grafts, and cuttings. Synergistic results are observed for the combination of the strains, and the combination of strains is useful to increase yield in crops including soybean and corn. The compositions containing the combination of strains can be applied alone or in combination with other microbial, biological, or chemical insecticides, fungicides, nematicides,
bacteriocides, herbicides, plant extracts,
plant growth regulators, and fertilizers.