苹果白粉病是苹果树的主要病害之一。据我们对钱家、风岭、东泉三个果园的调查,红玉、秋花皮和国光等品种的病叶率,高达60～80％,病梢率30～40％。为了探索粉锈宁防治苹果白粉病的效果,我们于1984年春、秋两季进行了防治试验,取得了很好的效果。现报告如下。材料和方法春季试验,在风岭一队果园的17年生红玉、国光、青香蕉上进行,单株小区,重复3次。秋季试验,在钱家果园18年生红玉上进行,单株小区,重复3次。供试粉剂为江苏建湖县农药厂出品的20％粉锈宁乳油.使用浓度为800倍液,春季,分别在5月5日 Apple powdery mildew is one of the major diseases of apple trees. According to our survey of Qianjia, Fengling and Dongquan orchards, diseased leaf rates of red jade, autumnal hulls and Guoguang are as high as 60-80% and the incidence rate is 30-40%. In order to explore the effect of triadimencin against apple powdery mildew, we conducted the prevention and treatment test in the spring and autumn of 1984 and achieved good results. The report is as follows. Materials and Methods Spring trials were performed on 17-year-old red jade, Guoguang and Qing bananas in a group of orchards in the Fengling Mountains. The single plantations were repeated 3 times. Autumn test, carried out in the money orchard 18-year-old red jade, single plant, repeated 3 times. Test powder for Jiangsu Jianhu County Pesticide Factory produced 20% triadimefon. The use of a concentration of 800 times the spring, respectively, on May 5