Symptoms of leaf spot: Leaves, petioles, shoots and pedicels may all be damaged, but mainly leaves. Symptoms are divided into two categories: one is the reddish-brown to purple-brown spots on the surface of leaves at the early stage of the disease, which gradually expand into circular or amorphous dark black spots, with yellow halo around the spots and radial edges, and the diameter of the spots is about 3- 15 mm, and small black spots are scattered on the diseased spots at the later stage, that is, the pathogen meristematic vesicles. In severe cases, the lower leaves of the plant wither and fall early, causing individual branches to die, such as rose black spot. The other is the appearance of brown to dark brown near-round or irregular wheel spots on the leaves, on which black mold, the conidia of pathogenic bacteria, grows. In severe cases, the leaves fall off early, which affects the growth, such as Ulmus pumila black spot. Black spot disease is the main disease on Chinese rose, which is widely distributed and harmful. The pathogen overwinters in dead branches or soil as mycelium or sterile hair. Infection began in the middle and late May of the following year, and the peak period was July-September. Conidia spread, expand and reinfect by wind, rain or insects. Rainwater is the main condition for the epidemic of diseases, and the onset is early and severe in years with early and abundant rain. Low-lying water, poor ventilation, insufficient light and improper fertilizer and water are all conducive to the onset. Control methods ① Select excellent disease-resistant varieties. (2) after autumn, clear the litter and burn it in time. ③ Strengthen cultivation management, pay attention to shaping and pruning, and be ventilated. (4) Spraying 50% carbendazim wettable powder 500- 1000 times, or 75% chlorothalonil 500 times, or 80% zineb 500 times, 7- 10 day for 3-4 times. -Leaf spot