Talc-based formulations of the two strains of Pseudomonas putida were tested separately and together for their ability to suppress the development of Fusarial wilt of muskmelon, caused by Fusarium oxysporum f. sp. melonis, under in vivo conditions in 2 consecutive years. In field trials conducted in 2001 and 2002, control efficacy achieved by seed treatment by the formulations of P. putida strain 30 was 63% and 46-50% for strain 180 at 90 days after transplanting. Seed treatment by the mixture of P. putida strains did not achieve as much effectiveness as biocontrol agents applied separately. Benomyl, used as reference chemical in both years, was less effective in reduction of the wilt severity of F. oxysporum f. sp. melonis than the bioformulation treatments.