一、发生动态 梨黑星病是我省梨果生产中的主要病害,以鸭梨为代表的中国梨系统较感病。50—60年代曾是梨的毁灭性病害,70年代以来,由于连续干旱,加之新农药的使用,控制了梨黑星病的发展,一直没有出现过大的流行。然而,进入90年代,病情发生了较大变化。1991年,全省范围内梨黑星病在雪花梨上流行,造成极严重的早期落叶, First, the occurrence of dynamic pear scab is the main disease in the production of pear in our province, pear pear represented by the Chinese pear system more susceptible. The pears were the devastating diseases in the 1950s and 1960s. Since the 1970s, due to successive droughts, coupled with the use of new pesticides, the control of pears scab has not been over-produced. However, into the 90’s, the disease has undergone major changes. In 1991, pears scab was prevalent in the snow pear across the province, resulting in extremely severe early deciduous leaves,