Kale black rot, black rot is mainly harmful to the leaves, the pathogen invades from the water hole, mostly from the edge of the leaf, and then extended inward as a "V"-shaped yellowish-brown spots, often with a yellow halo around the spot; sometimes the pathogen extends inward along the veins of the leaf. Produce yellow-brown spots or leaf veins blackened in a network, if the pathogen from the wound invasion, can be formed in any part of the leaf blade irregularly shaped yellow-brown spots. Belonging to bacterial diseases, you can use streptomycin, leaf blight, octreotide, mesotheliotoxin, thiobacillus copper, thiessence copper, copper quinoline, chlorobromoisocyanuric acid, polymyxin-like bacillus spores, etc. plus potassium dihydrogen phosphate spraying prevention and control, the interval of 5 days in the successive spraying of 2 to 3 times.