The symptoms of wilting often appear in the production of cucumber in protected areas, which often leads to plant death. With the increase of cucumber planting area, wilting diseases have aggravated year by year, which seriously affects the yield and output value of cucumber. The symptoms and prevention measures of several common wilting diseases in greenhouses and greenhouse cucumbers are described below. First, symptom recognition 1. Cucumber hypothermia. It is the physiological disease of acute withering caused by the loss of water from cucumber leaves. The acute leaf withering of cucumber leaves means that in a short period of time, the whole leaf of cucumber suddenly wilts and loses its ability to produce squash. The main reason is that the greenhouse cucumbers planted in autumn and winter or early spring are more prone to rain and snow, especially low temperature for a long period of time, and the ground temperature is low. When the root system is underdeveloped or grows weak, the plants are sunny, and the temperature in the shed is high during the day. Strong transpiration, roots can not absorb enough water and nutrients, resulting in sudden wilting leaves, a serious death of the whole plant. 2. Cucumber wilt disease. Cucumber can be infected during the whole growing season. The diseased plants in the early stages showed that the leaves gradually wilted from the bottom upwards, appearing to be lack of water, and it is more obvious at noon. It can be recovered sooner or later. After a few days, the whole leaf withered and no longer returned to normal. In wet conditions, the surface of the diseased part often produced a white or pink moldy layer. The bacteria live in the soil for winter, and they can survive for at least 5 to 6 years in the soil. The pathogens invade from the roots of the cucumber roots and wounds of the root hairs, grow rapidly in vascular bundle conduits, secrete enzymes and toxins, cause wilting of plants, and browning of the catheter. 3. Cucumber root knot nematode disease. The symptoms of the aboveground part are short and stunted. When the soil is dry and the water supply is insufficient, symptoms of wilting can appear before and after noon. The root symptoms are on the fibrous roots and lateral roots. The nodules with different sizes can be formed. The root section begins to milky white. At the end of the period, it turned light brown and cut the root section with a small milky white nematode. The disease is a root disease caused by root-knot nematodes. The nematode is wintered in the soil with eggs or 2nd instar larvae and can survive in the soil for 3-4 years. The nematode invades from the root tip of cucumber, colonizes the growth cone, and secretes stimulants to form giant cells and nodules. The survival temperature of nematodes is 25~30°C, which is generally harmful to sandy soils. Second, prevention and control measures 1. Use resistant varieties. There are no high disease-resistant varieties. Generally, they are moderately resistant. For example, Jinza No. 2, Jiha No. 1, Zhongnong No. 5, Changchun Mickey and Xintai Mickey. 2. Soil disinfection. Use 50% carbendazim WP 8g/m2 to treat the noodles. Before planting, use 20% of 50% carbendazim WP per acre, add 30 kg of fine dry soil, and mix evenly into the planting hole after mixing. 3. Implement rotation. It is best not to exceed 3 years for continuous cropping of cucumbers, and 3 to 4 years for crop rotation. 4. Grafting for roots. Using black seed pumpkin as the rootstock for grafting not only prevents disease, but also has obvious effect on increasing yield. 5. Control methods. For the acute leaf withering caused by cucumber cold temperature, pay attention to increase the ground temperature, especially the nighttime ground temperature should be maintained at 12-15°C or more. If the nighttime shed temperature is 8～10°C for a long time, when the daytime is sunny, the shed temperature will be very high. To rise quickly, slow warming measures should be adopted. If the greenhouse temperature rises above 30°C after sunrise, use the shade curtains to shading, so that the physiological function of cucumber can be restored slowly to avoid sudden wilting of leaves. Fusarium control can be used 2% agricultural anti-120 water 250 times liquid irrigation root, can also be used 50% of hymexazne wettable powder 3000 times Irrigation. Control root knot nematode disease, use 1.5 billion/gram of Streptomyces avermitilis and its active granules before planting, apply 2~3kg per acre, and use 18% avermectin EC at 1500 times in the growth period root. The above liquids should be used alternately. Generally, 0.25 kg of each liquid should be used for irrigation. The irrigation should be performed every 10 to 15 days, and irrigation should be repeated 2 or 3 times to reduce the incidence. Reference Electrode,Big Capacity Reference Electrode,Double Junction Reference Electrode,Compact Reference Electrode INESA Scientific Instrument Co., Ltd , https://www.inesarex.com