二、主要果树病害发生规 律及其防治 掌握病害的发生发展规律,是开展防治的主要依据。病害的规律主要包括以下几个方面;①病原在哪里越冬?②在生长季节开始后.病原怎样到达感病点?③侵染的时间和条件,是早春还是雨季、温湿度条件对侵染有什么影响?④有无再次侵染?⑤为害期多长; Second, the main fruit tree disease occurrence and prevention and control of disease occurrence and development of the law is to carry out the main basis for prevention and treatment. The law of disease mainly includes the following aspects: ① Where is the pathogen overwintering? ② After the beginning of the growing season, how does the pathogen reach the susceptible point? ③ The time and condition of the infection are in early spring or in the rainy season, What effect? ​​④ has no further infection? ⑤ long damage period;