The effects of biofertilizer and biostimulant application on tomato (Solanum lycopersicum L.) were this study’s focus for evaluation. The experiment examined the irrigation of rhizobacteria in different combinations, including B0 (plants irrigated with water only); B1 (plants treated with inoculant containing A. chroococcum (8.8 × 10⁹) with 10 g plant^-1; B2 (plants treated with inoculant containing B. subtilis (7.5 × 10⁹) with 10 g plant^-1; and B3 (plants treated with A. chroococcum in 10 g plant^-1) plus B. subtilis (10 g plant^-1) in tomato (Solanum lycopersicon L.). The use of biostimulant under the trade name “Deflan,” which contained organic matter (18.4%), amino acids (10%), total nitrogen (3%), and organic nitrogen (3%), had three levels (0, 0.250, and 500 mg l^-1). The combination of both A. chroococum and B. subtilis at 10 g plant^-1 had an influential effect, which reversed an increase in root and vegetative growth, specifically the content of macroelements. A biostimulant spray significantly affected all parameters, especially the 500 mg l^-1 dose. Furthermore, a solidarity effect markedly appeared, which raised all vegetative parameters, especially the biofertilizer treatment A. chroococcum (10 g plant^-1) plus B. subtilis (10 g plant^-1) with spraying biostimulant (500 mg l^-1). These results will contribute favorably to providing evidence for desirable effects from the interaction between biofertilizers and biostimulant spraying on tomato plant development.

Keywords: Tomato (Solanum lycopersicum L.), biofertilizers, rhizobacteria, azotobacter, Bacillus, foliar application, biostimulants

Key findings: The application of rhizobacteria and foliar treatment with biostimulant increased vegetative traits and mineral content of leaves, especially the mixture between A. chroococcum and B. subtilis (10 g plant^-1) in tomato (Solanum lycopersicum L.). Furthermore, foliar application of the biostimulant at a concentration of 500 mg l^-1 boosted all the parameters under study.