大白菜黑斑病(A lternaria brassicae)是大白菜生产中普遍发生而为害严重的真菌病害。1988年和1996年该病在北京市大白菜上曾大发生,严重地块甚至绝收,远望一片枯黄,一般地块损失30%～50%。全部地块病株率达100%,病情指数50～92,损失惨重。几年来,该病都有不同程度地发生和为害 Chinese cabbage black spot disease (A lternaria brassicae) is a common and serious fungal disease in Chinese cabbage production. In 1988 and 1996, the disease occurred on the Chinese cabbage in Beijing. The serious massif and even the bad ones were far-off and yellowish. The general mass loss was between 30% and 50%. All plots of disease rate of 100% of the disease, the disease index of 50 to 92, suffered heavy losses. In recent years, the disease has occurred to varying degrees and damage