Biocontrol of Fusarium oxysporum in cucumber by some antagonist bacteria under drought stress

Fusarium crown and root rot of cucumber caused by Fusarium oxysporum is one of the most important diseases in cucumber. Although various methods have been recommended to manage this disease, biological control is considered as an environmentally friendly method. In the present study, antagonistic effects of six Pseudomonas and Bacillus genera strains were investigated against F. oxysporum, where in vitro and in vivo assays were performed under drought stress. All of the strains were capable to inhibit the growth of F. oxysporum. The results of drought stress also indicated that the bacterial strains were able to tolerate different levels of drought stress. In general, Pseudomonas fluorescens VUPF5 caused the best inhibitory effect in all of the assays in vitro and under greenhouse conditions.