白菜三大病害(霜霉病、软腐病、病毒病)是黑龙江省牡丹江市秋白菜生产上的常见病害。近年来,特别是1997、1998年流行成灾,造成白菜平均减产30%以上,严重地块绝产。2000、2002年三大病害再度流行,虽然总体损失未超过1997、1998年,但发生面积仍占播种面积的60%以上,个别地块绝收 Three diseases of cabbage (downy mildew, soft rot disease, viral disease) is a common disease in the production of autumn cabbage in Mudanjiang City, Heilongjiang Province. In recent years, especially in 1997 and 1998 epidemic, resulting in an average reduction of more than 30% of cabbage, a serious block of junk. In 2000 and 2002, the three major diseases re-epidemic, although the overall loss did not exceed 1997,1998, but still occupy more than 60% of the sown area,