The damage caused by rice damping-off diseasecould be controlled efficiently by planting vig-orous seedlings.By adjusting the environ-ment,immunization of rice nursery(IRN)could raise seedlings with well developed rootsand high physiological activity.These The damage caused by rice damping-off diseasecould be controlled efficiently by planting vig-orous seedlings.By adjusting the environ-ment, immunization of rice nursery (IRN) could raise seedlings with well developed roots and high physiological activity.These