近年来,白菜霜霉病在东北、山东、河北和内蒙古等地区仍年有发生,为害严重。包头曾在1975、1977、1978年三次大流行,发病率高达80—90%,病指50—80%,减产50%左右。白菜霜霉病大流行不仅使生产遭受巨大损失,且波及市场供应。因此有效地防治白菜霜霉病的研究,仍然是生产上迫切需要解决的大问题。我所从1963年起即进行白 In recent years, cabbage downy mildew in the northeast, Shandong, Hebei and Inner Mongolia and other regions still occur, serious damage. Baotou had three pandemics in 1975, 1977 and 1978 with a prevalence of 80-90% and a disease index of 50-80%, a reduction of about 50%. Cabbage downy mildew pandemic not only suffered huge losses of production, and affect the market supply. Therefore, the effective prevention and control of cabbage downy mildew research is still an urgent need to solve the big problem. Since 1963, I have been doing white