Root-knot nematode Meloidogyne enterolobii

Systematic position: Meloidogyne enterolobii is a highly pathogenic plant-parasitic nematode belonging to the order Rhabditida and the family Meloidogynidae. Often referred to as the guava root-knot nematode, it is globally recognized as a significant quarantine pest due to its aggressive nature and wide host range.

Susceptible crops: The nematode has a diverse host range, severely affecting major vegetables such as tomatoes, peppers, cucumbers, and aubergines. It also impacts industrial and fruit crops like potatoes, sweet potatoes, guava, and various ornamental plants. It thrives particularly well in greenhouses where year-round cropping allows for rapid population buildup.

Biology and life cycle: The life cycle comprises eggs, four juvenile stages (J1–J4), and adult females. Infective second-stage juveniles (J2) migrate through the soil to penetrate host roots. Once inside, they induce the formation of giant cells within the root vascular system, which act as nutrient sinks for the developing parasite. The cycle is completed rapidly under warm conditions.

Damage and economic impact: Infected plants exhibit stunted growth, chlorosis, and wilting during periods of water stress. The most diagnostic symptom is the presence of extensive, large root galls that destroy root architecture, leading to nutrient and water uptake failure. Severe infestations lead to total yield loss and can be exacerbated by secondary infections from soil-borne fungi and bacteria.

Control measures: Management strategies must prioritize strict quarantine and exclusion measures to prevent the spread of the nematode. Cultural practices include using resistant rootstocks, crop rotation with non-host crops, soil solarization, and the application of biological control agents. Chemical control is limited and often ineffective, highlighting the importance of integrated pest management (IPM) practices.