The investigation of downy mildew of off-season cabbage and its pollution-free control experiment were earned out in Daxi town with a high elevation, Dafang county, Guizhou.

• 摘要2005年，在黔西北地区大方县达溪镇进行了夏秋反季节甘蓝霜霉病发生危害调查及田间药剂防效试验。