Cabbage soft rot is one of the three diseases on cabbage, also known as "rot disease", "grub", "rotting gourd", "pap cabbage", "off the help", "water rot" and so on. Chinese cabbage soft rot pathogens in addition to invade cabbage, but also invade potatoes, tomatoes, peppers, onions, cabbage, celery, lettuce, cauliflower, radish, cucumber and other vegetables, causing varying degrees of loss. With the adjustment of agricultural planting structure and the increase of multiple cropping index, the planting area of ​​summer cabbage has increased year by year, and the price is higher, which has good economic benefits. However, due to the continuous planting of Chinese cabbage in summer, suitable climatic conditions in summer, and inadequate disease prevention and control measures, cabbage rot occurs in a large area, the incidence rate is generally 5% to 30%, and serious can reach more than 50%, and some even Production, causing great economic losses to agricultural products. In order to reduce the loss of summer cabbage soft rot, comprehensive prevention and control measures should be taken. First, the infection cycle of cabbage soft rot bacteria infestation temperature range of 2 ~ 40 °C, the optimum temperature of 25 ~ 30 °C, bacteria can be with the disease in the soil, fertilizer, etc. or in the yellow striped flea, cabbage worms, etc. Overwintering in insects occurs through farmyard manure, rainwater, irrigation water, and insects. It is invaded by wounds or various physiological cracks caused by pests, artificial or mechanical damage, causing initial infection and re-infestation of diseases. Second, disease symptoms Chinese cabbage soft rot generally from the rosette period to the heart of the most severe disease, its symptoms are mainly based on rot, heart rot and rot outside the three types. 1. In the initial stage of the base rot, a small water-soaked lesion appeared on the petiole near the ground. The lesion quickly spread and gradually turned brown. The base tissue was rotted, the upper part of the leaf was dehydrated and wilted, and the diseased tissue was moist and soft. In the form of rotten egg smell. At the beginning of the disease, the external leaves wilted at noon and will recover sooner or later. In severe cases, the shortened stems and root canal are rotted, yellow-brown stinking mucus is secreted, and the outer leaves fall on the ground, and the leaf ball falls. 2. Heart-rot pathogens invade the cabbage core from the wounds of the petiole base to form water-soaked lesions, and then the lesions continue to expand and gradually turn grayish-brown or brown. The tissues are sticky and soft-rot. This type of symptom generally leaves the heart of the ball rot, the external disease-free symptoms, when the whole plant rot. 3. The external rot type external leaves edge scorch or in the rainy conditions, the top of the heart leaves rot, in the case of high temperature drying, the decomposed leaves of the rot leaves are thin paper-like, when the whole plant is soft rot, emits bad odor. Third, the comprehensive prevention and control technology The incidence of cabbage soft rot disease and variety resistance, cultivation and management measures, climatic conditions and insect damage conditions and other factors, therefore, the prevention and treatment of the disease should take prevention-based comprehensive prevention and control measures. 1. Selection of high-quality, disease-resistant varieties, generally Qingbang varieties are more resistant than white varieties, and sparse-hearted Chinese cabbage is more resistant than heart-shaped Chinese cabbage. At present, cabbage varieties resistant to soft rot such as Xia Kang 50, Xia Kang 55, Cai Bai No. 1, You Xia Wang, Lu Bai No. 13 and Zheng Bai No. 4 can be widely used in production. In application, attention should be paid to the purification and rejuvenation of disease-resistant varieties, and the quality of seeds should be improved. In addition, genes resistant to soft rot can also be used for disease-resistant breeding and new high-quality disease-resistant varieties can be selected. 2. Seed treatment soaked in warm water at 50°C for 20 minutes or soaked for 72 hours with 72% agricultural streptomycin 1000 times for 2 hours, can also use Fengling 50～100g for proper amount of water mixed seed 150g or agricultural resistance with seed quality 1%～1.5% 751 seed dressing, the seeds dried slightly after sowing. 3. Cultivation Management (1) Apply crop rotation or intercropping to avoid continuous cropping of Chinese cabbage with cruciferous, Solanaceae, and melon vegetables, and implement rotations with corn, rice, wheat, and other crops for 2-3 years or with leeks and onions Interplant with peppers. (2) The soil disinfection treatment can be combined with the base fertilizer and plowing, and the soil disinfectant such as Greenhenge No. 1 can be mixed in the soil. After the film is covered and compacted, the soil is disinfected. (3) The sorghum or high ridge cultivation sorghum or high ridge soil is rich in oxygen, water is not easy to accumulate in the soil, which is conducive to the formation of cabbage callus, and can reduce the chance of transmission of germs during rainfall or watering. Therefore, Chinese cabbage should be cultivated in high ridge or high ridge, and generally it can be 10 to 20cm in height or ridge height. The live broadcast should be conducted in an appropriate period, which can reduce the wounds caused by transplanting and reduce the chance of cabbage infestation. (4) Strengthen fertilizer and water management, remove diseased plants in combination with deep plowing, and increase trace elements. Organic manure must be fully cooked. Fertilizer topdressing should be carried out in phases and in batches in order to avoid burning the root leaves, which can be combined with watering. It is also possible to spray a foliar fertilizer such as a 0.3% potassium dihydrogen phosphate aqueous solution. Maintain a balanced water supply and prohibit flooding. Flood water along the ditch, and pay attention to the amount of water in the roof. After the rain, it should be drained in time. Before the watering, the diseased plant was removed and the sickle was disinfected with nitric acid or 300 times formalin; the agricultural activity of the cabbage field should be reduced as much as possible, which could reduce the production of the cabbage wound. 4. Insect pest prevention and control pests can not only directly harm cabbage, causing wounds, and some pests themselves with bacteria in the body, can cause the spread of disease, therefore, should pay attention to the control of pests in cabbage fields. From the beginning of the seedling stage, it is necessary to prevent and control pests such as ground tigers, golden needleworms, cockroaches, earthworms, cabbage caterpillars, flea beetles, leafhoppers, diamondback moths, and aphids. Can be combined with soil disinfection 15 to 21.5 kg of carbaryl per hectare to eliminate the underground pests. The control of Pieris rapae, Plutella xylostella, and Astragalus leucocephala can be performed by spraying 500 times of Bt emulsion, 25% of sweeping 2500 to 3500 times of liquid, or 5% of cypermethrin (2500 to 3500 times). 40% Dimethoate Emulsion 1500 times, 50% Pioneer Mist 1500x, or 5% Anti-Xeon 1000x can be used to control aphids. 5. Antimicrobial agent before the onset or early onset, can use antibiotics "401" 500 ~ 600 times, 72% of agricultural streptomycin 1000 ~ 1500 times, 70% of the enemy powder 500 ~ 1000 times fluid, 50% Daison ammonium 600 to 800 times, 0.5% OS to Sterling 600 to 800 times, neomycin to 3500 to 4000 times, 3% to Kecon 500 to Fengling to 400 to 800 times to green Hange No. 600 600 to 800 times, etc., spray once every 7 ~ 10d, continuous spray 2 ~ 3 times. When spraying, the liquid should be sprayed on the petiole and stem base near the surface of the plant. Can also be used with 100 ~ 150g Feng Ling 50kg water per 667 square meters to irrigate the root or with 77% of powder 600 times liquid Irrigation root. In order to meet the needs of pollution-free vegetable production, attention should be paid to the selection of biopesticides that have no residues and no pollution.