Mango sheathoid nematode

Pathogen and disease type
The mango sheathoid nematode (Hemicriconemoides mangiferae) is a microscopic phytoparasitic nematode belonging to the family Criconematidae. It acts as an ectoparasite that feeds on the roots of woody plants, leading to a disease characterized by root degradation, nutrient deficiency, and stunted tree growth.

Host plants
The primary host for this pest is the mango tree (Mangifera indica). However, it is a polyphagous parasite capable of infesting various other crops, including citrus, litchi, guava, and grapevines. Its ability to survive on multiple hosts makes it a persistent issue in diverse orchard environments.

Symptoms and signs of damage
Plants infested with the sheathoid nematode often exhibit a decline in overall vigor. Visible symptoms include yellowing of leaves, premature defoliation, and reduced fruit size or yield. Beneath the soil, the damage is evidenced by necrotic lesions on the root cortex, reduced root branching, and a general collapse of the fine root architecture required for water uptake.

Development and pathogenicity
These nematodes thrive in sandy soils with optimal moisture and temperatures ranging between 25°C and 30°C. By inserting their stylets into root cells, they extract nutrients and inject enzymes that weaken the plant's defense system. High population densities result in significant economic losses due to the diminished productivity and lifespan of the affected trees.

Protection and prevention measures
Management of Hemicriconemoides mangiferae requires a multifaceted approach focused on prevention and population suppression. Key strategies include:

• Strict use of nematode-free planting material from reputable sources.
• Soil analysis before orchard establishment to detect initial infestation levels.
• Application of organic amendments to boost beneficial microbial activity in the soil.
• Strategic use of nematicides or biological control agents (e.g., Paecilomyces lilacinus) in severe cases.