如果白菜帮上的黑点不是很多,可能是栽培过程中使用过多的氮肥造成的一种生理性病害。如果白菜受蚜虫的侵袭,可能会在白菜叶上留下黑色的粉末状物质,食用前用水冲洗掉,但是白菜上如果出现大块的黑斑或腐烂,可能是由于贮存中得了“黑斑病”或“软腐病”,这种的不宜食用。
If there are not many black spots on the cabbage, it may be a physiological disease caused by excessive use of nitrogen fertilizer during cultivation. If cabbage is invaded by aphids, black powdery substances may be left on the leaves of cabbage, which should be washed away with water before consumption. However, if large black spots or rot appear on cabbage, it may be due to "black spot disease" or "soft rot disease" during storage, which is not suitable for consumption.