For broccoli black spot disease, in the early stage of the disease, you can use 50% parahydantoin wettable powder 1000 times liquid, or 50% mefenacet wettable powder 800 times liquid, or 50% thiram wettable powder 500 times liquid, or 40% sterilant wettable powder 400 times liquid, or 64% antiseptic vitriol wettable powder 500 times liquid, or 50% Suclin wettable powder 1000 times liquid, or 70% mancozeb Spray wet powder 400 times liquid and other chemicals once every 7 days, and spray 3 to 4 times in a row.