Biocontrol activity of Trichoderma harzianum, Bacillus subtilis and Pseudomonas fluorescens against Meloidogyne incognita, Fusarium oxysporum and Rhizoctonia solani

Abstract

Repeated in-vitro trials were conducted to study the biocontrol potential of Trichoderma harzianum, Bacillus subtilis, and Pseudomonas fluorescens against Meloidogyne incognita, Fusarium oxysporum and Rhizoctonia solani. The interaction studies of biocontrol agents and pathogens showed that undiluted culture filtrates of T. harzianum, B. subtilis and P. fluorescens caused 100% mortality against M. incognita and inhibit its egg hatching up to 75%. M. incognita eggs were also found infected (up to 89%) when exposed to fresh culture of T. harzianum. Tested biocontrol agents caused growth inhibition against F. oxysporum and R. solani when exposed to dual culture bioassays. T. harzianum caused maximum growth inhibition against F. oxysporum (66%) and R. solani (99%) followed by P. fluorescens (40 and 83%) and B. subtilis (41 and 48%) respectively. T. harzianum, B. subtilis and P. fluorescens showed compatibility among them under in-vitro trials and did not show any negative impact on each other. In contrast, the interaction of biocontrol agents with all tested pathogens was recorded negative or antagonistic. Our findings proved that compatibility and biocontrol potential of T. harzianum, B. subtilis and P. fluorescens makes them a potential tool to control soil borne pathogens (M. incognita, F. oxysporum and R. solani), which may replace harmful and costly management options and could be an important component of IPM strategies for sustainable agriculture production.