Effect of Endophytic and Plant Growth Promoting Rhizobacteria against Foot Rot Disease of Piper nigrum L

Crop loss in black pepper (Piper nigrum L.) due to pathogenic diseases is mainly induced by soil borne fungi, bacteria, nematodes and viruses. Foot rot disease caused by Phytophthora capsici Leonian is a major production constraint in South India and other south East Asian countries. Combination of biocontrol agents that are compatible with each other is one of the emerging strategies to control plant disease and pest. The present study was designed to evaluate the protective effects of compatible endophytic fungal (Trichoderma harzianum Th16 and Th5) and rhizobacterial (Pseudomonas fluorescens Pf1) strains against pepper foot rot disease. Our results showed that T. harzianum (Th16 and Th5) and P. fluorescens (Pf1) were compatible and effectively inhibited the growth of P. capsici. The application of endophytic and rhizobacterial strains, alone and in combination in green house and field conditions were found to be effective in controlling the foot rot of pepper caused by P. capsici by inducing systemic resistance (ISR) as evidenced by enhanced activities of PO, PPO, PAL, β-1,3-glucanase, chitinase and total phenolics involved in the synthesis of phytoalexins thereby promoting the growth of plants. However, combinations of Th16 + Th5 + Pf1 were more effective than individual treatments. The findings suggest that synergistic interactions of biocontrol agents may be responsible for the management of foot rot of pepper caused by P. capsici.