近年来苹果白粉病(Podosphacra leucotricha(E.et E.)Salm。)在关中地区日趋严重,对倭锦、红玉等感病品种为害很大,例如武功西农果园倭锦春梢的初次发病率一般可高达20—30％;致使果树的新梢生长及产量受到显著影响。现将1960—1962年的主要工作结果简述如下。据观察3月下旬苹果新梢展叶后1—2天内即可于病叶丛上,见到新鲜的分生孢子层。4至 In recent years, Podosphacra leucotricha (E.et E.) Salm. Has become more and more serious in the Guanzhong area, causing great damage to the susceptible varieties such as Japanese Kam, Red Jade and so on. For example, The rate can generally be as high as 20-30%; resulting in fruit tree shoot growth and yield were significantly affected. The main results of the work from 1960 to 1962 are summarized below. It is observed in late March Apple shoot tip leaves within 1-2 days after the leaves can be found in the disease, see fresh conidia layer. 4 to