How to control mango powdery mildew

How to prevent and cure mango powdery mildew? Powdery mildew is an important disease in the flowering stage of mango, which is harmful to inflorescences, young fruits and young leaves. It occurs in Guangdong, Hainan, Yunnan, Guangxi and other producing areas in China. It has also been reported in India, Pakistan, Brazil, South Africa, Australia, Sri Lanka and other countries. Symptomatic mango powdery mildew mainly harms inflorescences and tender leaves, but also harms fruits. The symptoms are basically the same: some scattered white powdery patches first appear on the injured organs, then gradually expand and combine with each other to form a white powdery mildew layer. The tissue under the mildew layer gradually turns brown and necrotic. Inflorescence stalks and sepals are the most susceptible to disease. when these organs are susceptible, the bud stops developing and the diseased part is covered with powdery mildew layer; the base of the inflorescence turns brown first, and the branches turn brown gradually, causing falling flowers. The symptoms of the leaves appeared first from the back of the leaves, the powdery mildew layer mostly occurred in the midvein area, and the damaged leaves appeared light gray patches, and the damaged leaves deformed and fell early in severe cases. The fruit is mainly harmful to the young fruit, in severe cases, the powdery layer is often covered with the whole fruit surface, the skin of the diseased part becomes brown and cracked, and the damaged fruit is easy to fall off. Although the mildly diseased fruit can continue to grow, after the powdery mildew layer falls off, the diseased part shows purple patches, cracking and Lignification. The pathogen of mango powdery mildew is mango powdery mildew (Oidium mangiferae Berther), which belongs to half-known subphylum. The powdery mildew layer of the injured organs is the mycelium and conidia parasitized by the pathogen in the epidermis. The conidia are oval, unicellular, colorless and serial. There is no sexual generation. The disease of mango powdery mildew was overwintered by mycelium in infected older leaves and branches. When the environmental conditions were suitable in the next spring, the overwintering mycelium produced conidia and infected by airflow. Temperature is the main factor affecting the occurrence of mango powdery mildew. When the monthly average temperature is 21: 22 ℃, it is most suitable for the occurrence of powdery mildew. The effect of humidity is small, and it is beneficial to the occurrence of the disease when the relative humidity is about 70%, but it is also serious under drought conditions. If the application of nitrogen fertilizer is too much, the branches and leaves are soft and easy to be infected with powdery mildew. Zi Hua Mang, Gui Xiang Mang, Qiu Mang, Yuexi No. 1 and other varieties are more susceptible. Prevention and treatment method 1. Plant disease-resistant varieties. two。 Increase the application of organic fertilizer and phosphorus and potassium fertilizer, and control the excessive application of chemical nitrogen fertilizer. 3. Chemical control should be sprayed from the early stage of flowering, once every 15-20 days. The effective agents are: 20% trimethoprim EC 3000 times, 15% trimethoprim wettable powder 3000-4000 times, 40% polysulfide gel suspension 350500 times, 250,300 sieve sulfur powder and so on. It should be noted that sulfur agent should not be used when the temperature is too high, so as to avoid drug damage. Click to get more mango planting techniques click to get more fruit planting techniques