杂交水稻中后期是水稻生长的关键时期 ,也是水稻病虫害的易发期 ,做好水稻中后期的病虫害防治工作 ,是夺取粮食丰收的重要一环。1 .病害防治　我县地处皖南山区 ,气候条件极利于水稻稻瘟病的发生 ,因而水稻稻瘟病在我县病区历年发生都较为严重。在杂交稻中后期稻瘟病防治工作上 The middle and late hybrid rice is a critical period for rice growth and is also a prone period for rice pests and diseases. It is a key part of harvesting grain and pests to prevent and control pests and diseases in middle and late rice. 1. Disease prevention and control My county is located in the mountainous area of ​​southern Anhui, the climatic conditions are extremely conducive to the occurrence of rice blast, and thus rice blast in the county ward over the years are more serious. In hybrid rice in the late rice blast prevention work