# Effect of botanicals, organic nutrient sources, and bio-control agents on root-knot nematode (Meloidogyne incognita) infecting tomato

## TL;DR

This study shows that using plant-based oils, beneficial bacteria, and organic materials can effectively control root-knot nematodes in tomato plants, offering a safer and sustainable alternative to chemical pesticides.

## Contribution

The study introduces a sustainable, eco-friendly method combining botanicals, bio-control agents, and organic amendments to manage root-knot nematodes in tomato cultivation.

## Key findings

- Essential oils from Mentha spicata and Piper longum significantly reduced nematode juvenile survival and egg hatching.
- Combined treatments of botanicals, biocontrol agents, and organic amendments improved tomato growth and soil fertility.
- The treatments performed as well as the chemical nematicide Velum Prime 400 SC but with added soil health benefits.

## Abstract

Root-knot nematode (Meloidogyne incognita) causes up to 30% yield loss in tomato (Solanum lycopersicum) worldwide, and reliance on synthetic nematicides poses serious environmental and health risks. This study explores sustainable alternatives by evaluating the nematicidal potential of Mentha spicata and Piper longum essential oils and extracts, along with Bacillus amyloliquefaciens and B. subtilis, under both In vitro and microplot conditions. Essential oils exhibited significant juvenile mortality and egg hatching inhibition at low concentrations, outperforming solvent extracts. In microplots, all treatments—including combinations with organic amendments (farm yard manure, vermicompost, and paddy straw)—significantly reduced nematode populations, improved tomato growth, and enhanced soil fertility. The combined biocontrol treatments performed comparably to the chemical nematicide Velum Prime 400 SC, while also increasing soil organic carbon and NPK content (P < 0.05). These findings demonstrate that integrating botanicals, plant growth promoting rhizobacteria and organic amendments provides an effective, eco-friendly alternative for managing root-knot nematodes, contributing to resilient and sustainable tomato production systems.

Illustration depicting a sequence for improving plant health affected by root-knot nematode (RKN) infestation. It includes culture maintenance, in vitro testing of botanical and PGPR isolates on J2 and eggs, treatment application in microplots, and the use of botanicals, PGPR, paddy straw mulch, and manure. The process results in healthier plants with improved growth parameters and reduced nematode infection.