How to prevent and cure the brown spot of Magnolia magnolia?

How to prevent and cure magnolia brown spot disease? Please give guidance to Magnolia brown spot disease: 1. Symptoms: Brown spot disease mainly infects leaves. Disease leaf surface initially appears pale brown or yellow spots, later enlarged into round or irregular spots, 5-12 mm in diameter, dark brown edge, the center is gray, on which many black spots. Lesions can fuse with each other into amorphous large necrotic lesions. Generally, the disease begins in summer. The harm is more serious in August and September. 2. Pathogen and disease status: Magnolia brown spot disease, also known as spot disease, is a common disease of Magnolia. Magnolia grandiflora occurs all over the cultivated areas in China, especially in Suzhou, Nanjing, Wuhan, Shenzhen, Tianjin and Shenyang. Brown spot disease often causes a lot of leaves, affecting the landscape. 3. Control methods: 1. Magnolia grandiflora should be planted in fertile soil and sunny places. On poor soil. Fertilizer should be applied appropriately to strengthen tree vigor and improve disease resistance. 2. No matter in the courtyard or street green belt, it is necessary to remove the diseased leaves in time and destroy them intensively. Nursery seedlings should pay more attention to hygiene management, remove diseased leaves as soon as possible, reduce infection sources. 3. The early stage of brown spot disease in summer every year. 1:1:100 Bordeaux mixture can be sprayed for protection. Later, 800-1000 times solution of penkejun, 800 times solution of 50% methyl torzine wettable powder, or 800-1000 times solution of 75% chlorothalonil wettable powder can be sprayed to control the spread of diseases. Click for more Magnolia planting technology Click for more Flower planting technology