Root-knot nematode

[Home] [Insect and mite pests ] [ Diseases ] [ Nutrient disorders ] [ Nematodes ] [Glossary ]


Scientific Name: Meloidogyne incognita (Kofoid and White) Chitwood


Galls and egg masses on fibrous roots (left) compared with normal roots (W. Martin, APS).


Cracking on storage roots (G. Lawrence, APS).

Diagnostic summary

  • What you see on plants

- poor shoot growth, leaf chlorosis and stunting.


- galling of rootlets and severe cracking of roots on some varieties or formation of small bumps  or blisters on other varieties.


- severe longitudinal cracking of storage roots.


- brown to black lesions on flesh which are not evident unless  storage root is peeled. 

  • Can be diagnosed by presence of pearl-like swollen female nematodes in flesh of storage roots or in fibrous roots.

  • Worldwide in distribution.

  • Usually occurs in warmer areas. 


Economic importance

Geographical distribution


Life cycle


Host range



View full fact sheet