Root Knot Nematode

Symptom

Infected root tips become swollen and hooked. Above-ground symptoms vary according to the type of rice and the species of Meloidogyne. In upland conditons and shallow intermittently flodded land, all species can cause severe growth reduction, unfilled spikelets, reduced tillering, chlorosis, wilting and poor yield. Symptoms often appear as patches in a field. This disease is known to cause serious damage to deepwater rice. Prior to flooding, symptoms are the typical stunting and chlorosis of young plants. When flooding occurs, submerged plants with serious root galling are unable to elongate rapidly, and do not emerge above the water level. This causes death of the plants, leaving patches of open water in the flodded fields.