Root-knot nematode

Meloidogyne chitwoodi and Meloidogyne fallax

Foliar symptoms

• Patches with stunted growth and delayed flowering

Root symptoms

• Very small, elongated club-shaped swellings

Spread

• Nematodes survive in the soil, tubers and roots
• Spread via seed tubers
• Very extensive list of host plants.
• Crop rotation has no effect
• Maize is an important host for the root-knot nematode M. fallax
• Irrigation from early July enhances the infestation of the tubers
• Nematodes remain active at temperatures exceeding 5° C. The infestation of the root can also develop during storage

Possible confusion with

• Powdery scab (Spongospora subterranea)