Potential of Trichoderma spp., Bacillus subtilis and Pseudomonas fluorescens in the management of early blight in tomato

Abstract

ABSTRACT Early blight is a common challenge to tomato production all over the world. Microbial antagonists, unlike synthetic chemicals, are friendly to the environment and human health. In this study, five microbial antagonists were evaluated for their effectiveness in managing the early blight of tomatoes under greenhouse and field conditions. Microbial antagonists included two Trichoderma isolates, two Bacillus subtilis isolates and one Pseudomonas fluorescens isolate. Water and Tower 72 WP® were used as control and reference test, respectively. Data were collected on disease parameters and tomato yield. All treatments significantly reduced the per cent disease index compared to the control in the greenhouse and in the field. The per cent disease index recorded for Tower 72 WP® was comparable to the per cent disease index recorded for most selected antagonists. All treatments recorded significantly higher yields compared to the control in the greenhouse and in the field. Trichoderma isolates and Tower 72 WP® recorded the highest tomato yields in the greenhouse. Selected microbial antagonists were effective in managing early blight in tomato under greenhouse and field conditions and minimised yield losses caused by the disease. These should be integrated in the management of early blight of tomatoes to reduce the dependence on agrochemicals.