水稻穗期可发生多种病害。杂交稻上穗期主要有叶尖枯病、云形病、鞘腐病、叶黑肿病、稻纹枯病；粳稻主要有纹枯病、稻曲病、稻瘟病等。这类病害的共同特点是喜欢低温、高湿、阴雨的天气。病菌为害叶片或叶鞘，至水稻孕穗末期或整个稳期发病。发病时因叶尖叶片大量枯死，影响植 Rice diseases can occur a variety of diseases. There are mainly leaf-tip blight, cloud-shaped disease, sheath rot disease, leaf-swollen disease and rice sheath blight in hybrid rice. The japonica rice is mainly sheath blight, rice false smut and rice blast. The common feature of these diseases are like low temperature, high humidity, rainy weather. Pathogens damage leaves or sheath, to the late bouts of rice or the entire stable onset. When the disease leaves a large number of withered leaves, affect the plant