论文部分内容阅读
白榆干枯病在陕北１ａ内有２个发病高峰期，８月为感病高峰期，翌年４月为发病死亡高峰期。病原菌茎点霉菌（ＰｈｏｍａＳａｃｃ．）的分生孢子主要靠气流，雨水击溅传播，昆虫活动对传播也有一定影响。病原菌主要从伤口和皮孔侵入。感病最适温度为１８～２７℃，相对湿度６５％～１００％。树龄６～１１年生植株最易感病，感染后发病快，死亡率高。
White elm blight has two peak incidences in northern Shaanxi Province, and the peak is in August. The peak incidence of death in April is the following year. The conidia of the pathogen PhomaSacc. Mainly rely on airflow and rainwater splashes. Insect activity also has some influence on the spread. Pathogen mainly from the wounds and leprosy invasion. The optimal temperature is 18 ~ 27 ℃, relative humidity 65% ~ 100%. Plants aged 6 to 11 years are most susceptible to the disease, with rapid onset and high mortality after infection.