A method for increasing the vigor and/or crop yield of agricultural plants under essentially non-existent pathogen pressure, wherein the plants, the plant propagules, the seed of the plants and/or the locus where the plants are growing or are intended to grow are treated with an effective amount of a composition comprising a) the Bacillus subtilis strain with NRRL Accession No. B-21661 or a cell-free extract thereof, and/or a mutant of this strain or extract having all the identifying characteristics of the respective strain or extract as component (I), and b) optionally at least one chemical compound as component (II), selected from the active compound groups A) to J): A) strobilurins; B) carboxamides; C) azoles; D) heterocyclic compounds; E) carbamates; F) other active substances; G) growth regulators; H) herbicides; J) insecticides.
