王慧琳问:我种的早萝卜,长得挺大,但从中间变黑,然后逐渐烂成空壳,是怎么回事? 答:根据所述症状判断,是萝卜发生了“黑腐病”。这是一种细菌性病害,主要为害萝卜的根和叶。叶发病时,叶的边缘出现不规则的黄斑,叶脉逐渐变黑呈黑网状。根部感病,先是导管变黑(故称黑心),而后腐烂空心,成 Wang Huilin asked: I planted early radish, grew quite big, but dark from the middle, and then gradually become a rotten shell, what is going on? A: According to the symptoms of judgment, is radish occurred “black rot” . This is a bacterial disease, mainly root and leaf damage radish. Leaf onset, the edge of the leaves appear irregular macula, veins darkening black mesh. The root of the disease, the first duct black (so called black heart), and then rotten hollow, into