Biocontrol efficacy of Pochonia chlamydosporia against root-knot nematode Meloidogyne javanica in eggplant and its impact on plant growth

Root-knot nematodes are a major global agricultural pest. They infiltrate plant roots, reducing the plants' ability to absorb nutrients and water, which significantly affects agricultural productivity. Due to the restricted use of chemical nematicide, environmentally friendly alternatives have been explored. In this study, we developed a polymerase chain reaction (PCR) assay to detect Meloidogyne javanica, a root knot nematode specifically infectious to eggplant. Using this detection method, we assessed the nematicidal activity of the biocontrol agent Pochonia chlamydosporia against M. javanica infection. We also assessed the in vitro mortality of M. javanica J2 larvae and eggs hatching following treatment with P. chlamydosporia. Additionally, we performed assays for penetration, population, and reproduction in pots containing eggplants infected with M. javanica and treated or untreated with P. chlamydosporia. P. chlamydosporia at various doses significantly inhibited M. javanica egg hatching and second-stage juveniles. It effectively reduced the number of galls, egg masses, and the nematode population in the roots of pot-grown eggplants. Furthermore, P. chlamydosporia treatment improved the growth parameters and photosynthetic pigments of eggplants while decreasing infection. Thisstudy highlights the potential of P. Chlamydosporia in managing root knot disease in eggplant.