The present invention relates to a method of treating seed, comprising applying at least one plant treatment agent to said seed； and applying a dry formulation comprising/consisting of spores of P. bilaii and talc powder to said seed. The invention furthermore relates to a formulation for use in seed treatment comprising spores of P. bilaii and talc powder, seed treated with such formulation and methods of improving applicability and quality of P. bilaii spores and methods of improving plant growth, plant health or plant vigor.
