How to prevent cucumber downy mildew?

How to prevent cucumber downy mildew? Please introduce that cucumber downy mildew is one of the most common and serious diseases on cucumber, which can occur in the whole growth period of cucumber and mainly damage leaves. After the damage to the leaves, the water stains appeared at the beginning of the light green spots, and gradually became yellow-green and yellow. It happens all over the city, which causes great threat and loss to cucumber production, so it is necessary to take preventive measures against cucumber downy mildew. First, select disease-resistant varieties. According to several years' cultivation practice, Jinyan series cucumber and Jinchun No. 4 cucumber have certain resistance to downy mildew. Those self-retained cucumber varieties and some local varieties, such as white cucumber in Dongyang, are prone to downy mildew. In some farmers, downy mildew has been seriously damaged and the harvest of cucumbers has been destroyed at the beginning. Therefore, special attention should be paid to seed selection. Second, strengthen cultivation management to achieve fitness cultivation. Cucumbers should be planted in sandy soil with high terrain and good drainage. Fertilization should be combined with nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer to improve the disease resistance of the plant. Greenhouse plastic greenhouse and other protected cultivation should have a good grasp of greenhouse and humidity in the greenhouse. In the field, there should be no stagnant water in the ditch, clear and loose soil after rain, proper cultivation of soil, straw and wheat stalk can be used to cover the border. Pruning and leafing should be carried out in time, and 0.3% urea or 0.2% potassium dihydrogen phosphate can be used for foliar topdressing in the late growth stage. Third, chemical prevention and control. When central diseased plants are found in the field, 40% aluminum phosphate 300 times or 25% metalaxyl 600 times, 64% alum 500 times, 70% mancozeb 500 times and other flushing sprays can be selected, with an interval of 7-10 days, and the frequency of medication can be determined according to the condition and weather conditions. Plastic greenhouses and other protected areas can also be fumigated, such as 45% chlorothalonil smoke remover 200-250 grams per mu, 4-5 places after closing the shed in the evening, lit by dark fire for one night, ventilation the next day, once every 7-8 days, can effectively control the disease. Click to get more cucumber planting techniques click to get more vegetable planting techniques