苹果斑点落叶病自70年代发生以来,在全国苹果产区为害呈上升趋势。近几年在我市发生严重,且逐年扩大蔓延。为研究该病的发生与防治,1991年在全市进行了大面积的调查研究,现报告如下:一、调查方法在我市五县两区范围内进行随机选择果园,调查时每果园采用五点式取样,每点取一株,每株随机调查400片叶,并记录调查结果,计算病叶率及病情指数。二、调查结果1.发生范围与为害程度:通过对市内76个果园,368株苹果树的调查,该病在各县区普遍发生,且发病严重。全市病叶率为41.3％,病情指数 Apple blight deciduous disease since the 70s has occurred in the country apple crop damage is on the rise. Serious in our city in recent years, and gradually expanded and spread. In order to study the occurrence and prevention of the disease, a large area survey was conducted in 1991 in the city. The report is as follows: I. Methods of investigation Randomly select orchards in the five districts and counties in our city. During the survey, Sampling, each point of a strain, each plant 400 leaves random survey, and record the survey results, calculate the disease leaf rate and disease index. Second, the survey results 1. Occurrence and extent of harm: Through the city of 76 orchards, 368 apple trees survey, the disease occurs in all counties, and the incidence is serious. The city sickness rate was 41.3%, the disease index