Effects of Bacillus subtilis, Pseudomonas fluorescens and Aspergillus awamori on the wilt-leaf spot disease complex of tomato

The effects of Bacillus subtilis, Aspergillus awamori and Pseudomonas fluorescens on the wilt–leaf spot disease complex of tomato caused by Meloidogyne javanica, Ralstonia solanacearum and Xanthomonas campestris pv. vesicatoria were observed. Inoculation of B. subtilis, A. awamori and P. fluorescens caused a significant increase in plant growth and chlorophyll contents of pathogen-inoculated plants. Inoculation of P. fluorescens caused a greater increase in plant growth and chlorophyll contents of pathogen-inoculated plants than that caused by A. awamori. Application of P. fluorescens with B. subtilis caused a greater increase in plant growth and chlorophyll contents of pathogen-inoculated plants, but the maximum increase was observed when all the three biocontrol agents were inoculated together. P. fluorescens colonized tomato roots more than colonization by B. subtilis. Root colonization by P. fluorescens and B. subtilis was reduced when pathogens were inoculated with rhizobacteria. Inoculation of P. fluorescens caused a greater reduction in galling and nematode reproduction, followed by B. subtilis and A. awamori. Maximum reduction in galling, nematode reproduction, wilt and leaf spot disease indices was observed when all three biocontrol agents were used together.