Biological Control of Meloidogyne incognita by Pochonia chlamydosporia in Tomato Under Greenhouse Conditions

Abstract

Root-knot nematode Meloidogyne incognita is a major constraint in tomato production under greenhouse cultivation, causing severe root galling, reduced nutrient uptake, and significant yield losses. Greenhouse experiments were conducted to evaluate the biological control potential of Pochonia chlamydosporia against M. incognita in tomato plants. The antagonist fungus was applied to the rhizosphere as a bio-inoculant prior to nematode infestation, and its effects were assessed in terms of gall formation, nematode population density, plant growth parameters, and yield performance. Results demonstrated that P. chlamydosporia significantly reduced egg mass formation, juvenile penetration, and gall development compared with untreated inoculated controls. Microscopic observations confirmed parasitism of nematode egg masses by the fungus, leading to degradation of eggs and reduced hatchability. Treated plants exhibited improved root architecture, enhanced shoot growth, and increased biomass accumulation, indicating effective mitigation of nematode-induced stress. The fungus successfully established in the rhizosphere and maintained persistent activity throughout the cropping period under greenhouse conditions. Reduction in nematode reproduction factor and soil population density further confirmed its suppressive effect on M. incognita. Environmental conditions within the greenhouse, particularly moderate temperature and adequate moisture, supported both fungal activity and plant growth, enhancing overall disease suppression efficiency. The biological control efficacy observed in this study highlights the compatibility of P. chlamydosporia with tomato cultivation systems and its potential integration into sustainable nematode management programs.