The Causes and Prevention of "Running Horse Drying" of Cucumber in Open Field

The "race horse" of cucumber is due to infection with downy mildew, and the onset conditions are very suitable, causing rapid onset of disease. The whole leaf of the plant is infected within 7-10 days, and then the leaves are dry and brittle, so the farmers call it "the horse". "Or "dry leaves." This disease is very common.

First, the reasons for the occurrence: 1. Temperature and humidity effects, including humidity is the main factor. The relative humidity is above 80%, especially after the rain or when the dew is too large. The leaves are affected by the presence of water droplets. The temperature of the sporangia germination is 5-32°C. -22°C. 2. There is a significant difference in disease resistance among varieties, and generally early spring cucumber varieties are susceptible to disease. Jin research series of cucumber varieties, Ningyang, cucumber and other varieties than the downy mildew. Cucumber plants differed in disease resistance at different stages of their development, and their resistance to disease was weak at the beginning and end of the melon period and at the fruiting stage. Mature leaves, because the pores have been fully developed, is conducive to the invasion of bacteria, it is often the first disease. 4. Reasonable cultivation and management, plant growth and development robust, increased disease resistance. Improper watering, poor ventilation, high humidity, and severe disease in fields closed. Cucumber is more severe than cucumber.

Second, prevention and control measures: 1. Selection of disease-resistant varieties, such as Jinyan series of cucumber varieties, Ningyang Thorngut, Xiafeng No. 1, and the hybrid generation of cucumber varieties. 2. Strengthen seedling management. On the basis of applying basic fertilizer and cultivating strong seedlings, attention should be paid to several times of cultivating and cultivating seedlings in the seedling stage to promote root growth. This is an important measure to increase disease resistance. 3. Increase phosphorus and potassium fertilizers to promote coordinated development. Look at the sky, see the land, see the seedlings watering, especially in the spring, generally should be selected to water the south wind day. 4. Conduct field investigations frequently and find that the central diseased plants are spraying pesticides in time. It is best to spray once before planting. When the melon vine grows to 50-80 cm high, spray it regularly and spread the liquid spray uniformly. The available agents are 40% 300% aluminum phospho-aluminum, 75% chlorothalonil 600 times, 65% dexamethasone 500 times, and 1000 grams of thisomusporin. If 0.3-0.5% urea is added to the drug solution, the control effect can be improved. During the peak of onset, watering should be properly controlled, timely weeding, old leaves, increased ventilation, and reduced humidity. If you need watering, it is best to use topdressing nitrogen fertilizer to increase plant resistance to disease.