Vegetable Root-Knot Nematode

📖 Description

Vegetable Root-Knot Nematode (Meloidogyne incognita) is the most important plant-parasitic nematode in the Indian subcontinent, attacking over 2000 plant species including tomato, brinjal, chilli, okra, cucurbits, cotton, tobacco and numerous weeds. The pest is particularly severe in vegetable belts of Maharashtra, Karnataka, Andhra Pradesh, Telangana, Tamil Nadu, Gujarat, Uttar Pradesh and West Bengal where continuous vegetable cropping is practiced. The pest induces characteristic irregular root galls that interfere with water and nutrient uptake, leading to stunting, yellowing, wilting and reduced yield. The pest is particularly damaging because (a) it is microscopic and often not detected until galls are visible on roots, (b) it has a wide host range making rotation difficult, (c) once established in a field, it is virtually impossible to eradicate, and (d) it interacts synergistically with other pathogens (Fusarium, Rhizoctonia) to cause disease complexes that are more severe than either pathogen alone. The pest is most severe in sandy soils, continuous vegetable cropping and irrigated agriculture. IPM with biocontrol (Paecilomyces lilacinus, Pochonia chlamydosporia), resistant varieties (carrying Mi gene in tomato), crop rotation with non-host crops (mustard, marigold, sorghum), soil solarization, organic amendments, and marigold as a rotation crop (roots release alpha-terthienyl that kills nematodes) provides effective suppression. Marigold rotation is one of the most effective and environmentally sustainable control measures — planting marigold for 2-3 months between vegetable crops can reduce M. incognita populations by 70-90%.