How to prevent and cure yellowing of magnolia?

How to prevent and cure yellowing of magnolia? Please introduce Magnolia yellowing, also known as chlorosis, is a common disease of Magnolia, especially in areas where the soil is slightly alkaline. The disease is more serious in this area of our country. The disease of the symptomatic plant begins with the young leaves at the top of the tip. The mesophyll tissue of the diseased leaf turns yellow or light yellow, while the leaf vein remains green. With the development of the disease, the whole leaf becomes yellow to yellowish white, and the leaf margin becomes grayish brown or brown and necrotic. The disease became more and more serious, the growth of the plant weakened and eventually died. Etiology Magnolia yellowing is a non-infectious disease, that is, physiological disease. The main cause of the disease is that the soil is heavy, moist and alkaline, which makes iron insoluble, which leads to iron deficiency in the plant. Control methods 1. Magnolia should be planted in sunny, well-drained, fertile and loose acidic soil. Acid soil such as mountain mud should be used in potted soil, and the new soil should be replaced once in 1 ~ 2 years. 2. At the initial stage of the disease, the rhizosphere soil can be irrigated with 30: 50 times of ferrous sulfate (black alum), or mixed retting with "alum fertilizer water" (2.5 kg of ferrous sulfate, 5 kg of bean cake and 15 kg of pig manure). After 10-15 days of fermentation and ripening, the experience of Henan Yanling flower farmers) and clear water were watered at intervals. The foliar surface can also be sprayed with 0.1-0.2% ferrous sulfate solution. Click for more magnolia planting techniques click to get more flower planting techniques