The host and parasite relationship is so strong that rice root nematodes have been found in all rice growing countries. In the absence of rice, the weeds, cabbage and other vegetables, cotton, maize and sugarcane may serve as hosts for Hirschmanniella species. The application of straw ashes, neem and mustard cakes reduces the rice root nematode populations in the soil as well as roots. Due to damage to roots, retardation of growth, stunting of plants, chlorosis and the reduction in the number of tillers may be observed when compared with the normal plants. Intercropping with trap plants like Sesbania rostrata or Sphenoclea zeylanica also helps in reducing the rice root nematode populations. The juveniles hatch and develop in the root cortex. Since hatching and developmental stages may take place within the host plant, the number of nematodes increases with the development of root system.