In vitro and in vivo studies of Vitex negundo-derived silver oxide nanoparticles against Meloidogyne incognita (Root-knot nematode) on tomato plants

Abstract

Meloidogyne incognita (M. incognita) is an important obligatory pest affecting a large number of horticultural crops. The pest is widely distributed in tropical, subtropical, and warmer regions of the world. M. incognita induces root gall formation that interferes with nutrient supply leading to stunted growth, wilting, chlorosis and significant drop in plant productivity. In recent years biogenic nanoparticles have emerged as an alternative approach for controlling agricultural pests. The current study investigates the nematicidal potential of green-synthesized silver oxide nanoparticles derived from Vitex negundo against second-stage juvenile (J2) and eggs of M. incognita. The maximum mortality (97.20 %) of M. incognita was found after 96 h of treatment. The lowest egg hatching (7.40 %) in comparison with the control (86.93 %) was found in 500 ppm concentration after six days of exposure. The bioassay results revealed that both juveniles and eggs generally showed a concentration-dependent response. The in vivo treatment with biogenic nanoparticles showed reduced gall formation and increased plant growth in tomato plants. Maximum reduction in the galls and plant growth parameters was observed in higher concentrations (1000 ppm) of VND-AgONPs after 60 days compared to untreated inoculated control. To best of our knowledge, this is the first report of the nematicidal efficacy of VND-AgONPs against J2 and eggs of M. incognita. These biogenic nanoparticles could be recommended for managing Root-knot nematodes due to their higher efficacy, cost-effectiveness, and environmentally safe nature.