| Summary: | Secretion of siderophores by <i>Pseudomonas aeruginosa</i> F2 and <i>P</i>. <i>fluorescens</i> JY3 was evaluated on chrome azurol S (CAS) agar plates and their inhibitory effect was inspected against <i>Fusarium oxysporum</i> and <i>Rhizoctonia solani</i>. Production of siderophores as biocontrol agents from F2 and JY3 was accomplished in two optimized media. Afterward, cell-free supernatants of the bacterial cultures containing siderophores were used for the preparation of two bio-friendly formulations for the management of <i>F</i>. <i>oxysporum</i> and <i>R</i>. <i>solani</i> under greenhouse conditions. The investigated bacterial isolates, F2 and JY3, showed antagonistic activity in vitro against <i>F</i>. <i>oxysporum</i> and <i>R</i>. <i>solani</i> and produced siderophores in optimized media with high efficiency. Colonies of both bacterial isolates were grown exponentially with a constant specific growth rate of 0.07 h<sup>−1</sup> and 0.27 h<sup>−1</sup>, correspondingly. Siderophores estimated in 10 µL reached their highest value of 16.95% at 47 h and 19.5% at 48 h for isolate F2 and JY3, respectively. Formulations of siderophore-generating F2 and JY3 reduced damping-off caused by <i>F</i>. <i>oxysporum</i> by 40% and 80%, while the reduction percentage of damping-off caused by <i>R</i>. <i>solani</i> reached 87.5% and 62.5%, correspondingly. Moreover, both formulations encouraged the growing of wheat plants where the fresh and dry weight of shoots and roots were increased compared to the treatment with each fungus. In conclusion, bio-friendly formulations resulting from this investigation can play an active role in managing soil-borne diseases.
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