Cucumber powdery mildew, also known as "white hair" disease, is prone to onset in cloudy days. The disease mostly occurs in the middle and late stages of the plant, and it mainly damages the leaves. In severe cases, it can extend to petiole, stem vine and tendril, but the fruits and fruits are usually less affected. At the beginning of the disease, white small spots were produced on the front and back sides of the leaves, and then expanded and contiguous with a layer of white mold. White mold edge is not neat, later turned gray. Leaves yellow, brittle and dry. It usually starts from the bottom leaves and gradually develops upwards. By the late onset of disease, in the undesired environment, piles of yellow-brown to black granules are produced in the white powder layer of the aging leaves or on the surface. Once the disease develops rapidly in greenhouses, it can cause leaf dryness and even premature pull, which has a great impact on cucumber yield. In addition to endangering cucumber, it can also harm zucchini, melon, pumpkin, watermelon, wax gourd, loofah and so on. The pathogens overwinter on mycelium and cyst melons with mycelium and closed capsules; the pathogens are like high temperature and high humidity, but they are resistant to drying when the temperature is 20～25°C and the relative humidity is 70%～85%. Most conducive to disease. In particular, the cucumbers in spring greenhouses are in a prosperous period, which is also the peak period of water requirement for fertilizers. Therefore, the farming of big fertilizers and waters causes the environmental conditions in the shed to be suitable for the occurrence of powdery mildew, so even if various kinds of pharmaceuticals are used, The control effect is also not obvious. Control methods: Control cucumber powdery mildew, prevention is the most important, farmers must be based on the situation, seedlings, conditions, develop the habit of spraying protective fungicides to ensure a good harvest. (1) Smoke-cleaning treatment of chlorothalonil. (2) At the beginning of the disease, 2% of farm resistance 120 or 200 parts of Wuyimycin can be sprayed, 10% of World High 1500 times, 40% of DuPont Fuxing 5000 times, and 47% of Garrett 600 to 80O times of liquid. Drug rotation, every 7 to 10 days 1, even spray 3 to 4 times. Waterproof Wound Dressing,Rectangle Big Wound Dressing,Waterproof Adhesive Wound Dressing,Medical Fixation Wound Dressing Surgimed Medical Supplies Co.,Ltd , https://www.surgimedcn.com