梨果煤污病的发生与防治适宜的气候条件和不合理的用药，是导致梨果煤污病严重发生的重要原因。７月上旬～８月下旬降雨频繁，高温、高湿适宜该病的发生。果园郁闭，通风透光性差，地势低洼也易发病。６～９月连喷２～３次１∶３∶３００倍波尔多液的园片很少发病；喷布其... The occurrence and prevention and cure of pears, coal pollution, suitable climate conditions and irrational use of medicines are the main reasons leading to the serious occurrence of pear pollution. Early July to late August frequent rainfall, high temperature, high humidity suitable for the occurrence of the disease. Orchard closed, poor ventilation and light, low lying and prone to disease. 6 ~ September even spray 2 to 3 times 1: 3: 300 times the Bordeaux mixture rarely infested;