作物侵染性病害的发生发展,有一定的过程,简称“病程”。病程可分为三个时期,即侵入期、潜育期、发病期。了解这三个时期中的病源、环境、寄主三者的相互关系,在病害防治上是有重要意义的。侵入期病菌渡过休眠期之后,菌体迅速产生各种繁殖器官,形成各种孢子。孢子成熟后,借风、雨、气流或自身动力传播。遇到适宜的寄主、又有适宜的温湿条件就能萌发,如果是真菌便伸出芽管,芽管的顶端形成“附着器”,附着器下伸出侵入丝,随即侵入寄主并初步建立 Occurrence of crop disease development, there is a certain process, referred to as “disease course.” Course of disease can be divided into three periods, that is invasive, latent period, the onset period. To understand the relationship between the pathogen, the environment and the host in these three periods is of great significance in disease prevention and control. Invaded bacteria through the dormant period, the bacteria quickly produce a variety of reproductive organs, the formation of various spores. Spores mature, by the wind, rain, air or self-motivation. Encounter the appropriate host, there are suitable conditions of warm and humid germination, if it is fungus will germination, the top of the germ tube to form an “attachment”, sticking out of invasive silk under the attachment, then invade the host and initially established