Downy mildew and keratoses are common diseases in open field or cucumber cultivation in greenhouses. They can be mixed and the initial symptoms are similar and difficult to identify. If inaccurate diagnosis of blind spraying, not only can the disease not be controlled effectively, but also it can increase The cost and pesticide pollution caused undue losses. Therefore, “fast, early and accurate†dialectical treatment is the key to effective prevention and control. First, the identification of downy mildew and keratoses Similarities of the two diseases are mainly damage the leaves, leaf back showed flooding, and chlorotic spots, lesions are limited by veins, showing a polygon. Different points 1. Different pathogens: Downy mildew is caused by pathogenic fungus parasitism, while angular spot disease is caused by pathogenic bacterial infection. 2. Different lesions: The lesions of keratoses are smaller than those of downy mildew, and they are initially stained with oil-like spots. The edges are stained with halo rings with lighter shades and appear paler grayish white. The lesions of downy mildew have large polygon spots, which are water-stained spots with darker colors and mostly yellow-brown. 3, perforation of different phenomena: leaf spot lesions easily cracked or late perforation off, and downy leaf is easy to wrinkle dry and not perforated, severe lesions contiguous, the whole leaves become yellow and dry. 4. Diseases on the back of the leaves are different: When the humidity of the keratoderma is large, the water is immersed obviously, resulting in milky pus, while the downy mildew does not show flooding when the humidity is high. There are black or gray frost-like mold layers on the lesions. . 5. Diseased leaves have different light transmission: leaf spot leaves are light-transmitting and downy mildew is not transparent. Second, prevention and control measures Due to the different pathogens of the two diseases, their prevention and control methods are also different. Prevention of downy mildew 1. Select disease-resistant varieties, such as Jinyan and Jinyou series. 2. The nursery is isolated from the production site and the field strains should be cleared in time. 3, choose a higher terrain, conducive to the drainage of the cultivation of the field, at the same time enough base fertilizer, growing season appropriate topdressing nitrogen fertilizer, improve plant resistance. 4, less water before the melon cultivator, increase the temperature, reduce water loss. 5, chemical control: After the onset of the disease can be sprayed with 72% Propidurone 800 times liquid, 75% chlorothalonil powder or 25% metalaxyl powder 800 times. Prevention and treatment of angular spot 1, choose disease-free species of melon seeds, seed disinfection. 2, no soil disease seedlings, and non-guarantee crop rotation for more than 2 years, the base fertilizer increased organic fertilizer and phosphorus and potassium fertilizer, avoid partial nitrogen fertilizer. 3, timely removal of field sickness, greenhouse cultivation in early spring, less watering, more cultivator, improve the temperature of the greenhouse; sooner or later ventilation, reduce air humidity, reduce condensation time, strengthen field drainage. 4. Chemical control: In the early stage of disease, 77% of wettable powder can be sprayed with 1200 times liquid, 12% of green milk copper emulsion 600 times or 72% of agricultural streptomycin sulfate 4000 times. For the prevention and control of two kinds of diseases 7-10 days to spray 1 drug, spray a total of 2-3 times. Silicone Stomach Tube,Medical Disposable Silicone Stomach Tube,Medical Disposable Silicone Tube,Disposable Silicone Feeding Tube Shaoxing Jenston Medical Products Co., Ltd. , https://www.sxjcmed.com