Biological control of Pectobacterium carotovorum subsp. carotovorum, the causal agent of bacterial soft rot in vegetables, in vitro and in vivo tests

Background Several chemical bactericides were applied for controlling soft rot bacteria, Pectobacterium carotovorum subsp. carotovorum, which causes the destructive soft rot disease to many economically important vegetables, but because of their toxic hazards on human and environment became limit. The biocontrol was applied to control many plant pathogens. Therefore, this work is aimed to study the antagonistic activity of bacterial agents, i.e. Bacillus subtilis, Bacillus pumilus, Bacillus megaterium and Pseudomonas fluorescens, and fugal agents, i.e. Trichoderma harzianum, Trichoderma viride and Trichoderma virens, to control bacterial soft rot disease under in vitro and in vivo tests. Results The tested treatments could protect the potato tubers against the development of soft rot. T. viride and T. virens were highly effective in reducing soft rot symptoms on inoculated potato tuber slices, when applied at the same time or 2 h before pathogen inoculation, while B. megaterium and T. harzianum were highly effective when applied at the same time or 2 h after pathogen inoculation. In whole potato tubers technique, B.pumilus highly protected the stored potato tuber under artificially infection conditions, than P. fluorescens, T. harzianum, B. subtilis, T. viride, T. virens and B. megaterium, respectively. Conclusion Application of fungal agents or specify the bacterial species can play an important role in controlling bacterial soft rot disease in vegetables and increase the stored periods of potato tubers under storage conditions without any toxic effects.