Occurrence and Control of Cucumber Wilt Disease

Cucumber fusarium wilt, also known as turfgrass disease, is a kind of half-species bacterium, which belongs to the cucumber specialization type of Fusarium oxysporum. It is a systemic disease (catheter-type wilt disease) that is transmitted from the soil, invades from the roots of plants or roots, and inhabits vascular bundles. First, the incidence of symptoms sectioned diseased stems, vascular bundles were tan to dark brown. When the soil is wet, there is a white fluffy material in the root and neck, which is the mycelia and conidia of the pathogen. Seedling stage (after seedling unearthing) two pieces of cotyledon uneven yellowing, and wilting drooping, distorted deformity, roots and roots Department rotten brown, plant growth stagnation, wilting dead. During flowering and melon-stage infection, the lower leaves of the diseased plants retreat green and turn yellow at first. Afterwards, the symptoms of dehydration and wilting at noon and gradually recovering in the evening are repeated. After repeated development, the leaves develop to the upper leaves. After a few days, the plants die. The vines of the diseased plants are longitudinally basally divided, with pink glial and conidium layers on the surface (lower diseased plants, leaf veins of the lower leaves retreat green, yellow spots appear on the mesh). Some plants appear half-wilted and half normal, which is due to part of the plant's vascular bundles being infected. Second, the incidence of disease Wilt disease mainly with mycelium, thick-walled spores and sclerotia in the soil, sick and unripe manure fertilizer overwintering, becoming the main source of secondary disease in the following year, the bacteria viability, in the soil Can survive 5 to 6 years. Diseases mainly rely on rain, irrigation water, soil cultivation, seeds, underground pests, and nematodes. Due to the infestation of underground pests and nematodes, the wounds of the roots are infected. Therefore, soils with a large number of insect pests are severe. The occurrence and prevalence of disease depend on the amount of the initial infestation in the year and the following factors: (1) Due to the accumulation of pathogens in the soil, the incidence of wilt disease is positively correlated with the duration of cucumber continuous cropping. The longer the continuous cropping period, the heavier the disease, the old vegetables The district is heavier than the new district. (2) Soil viscous weight, low-lying terrain, poor irrigation drainage, cold and wet soil, extensive farming, and unfavorable root development of cucumber, and occurrence of blight disease. (3) Insufficient fertilization, lack of organic fertilizer and excessive partial nitrogen fertilizer application, and application of unrefined basal fertilizer, the incidence of disease. (4) Acidic soils are not conducive to the growth of cucumbers and are conducive to disease occurrence. Soils with pH 4.5 to 6 are heavier, and soils below pH 3.5 and above pH 9 are not affected. (5) It is related to variety and germplasm, and the incidence of susceptible varieties is heavy. (6) It is related to the soil temperature. The soil temperature can be between 8 and 34°C, and the incidence is the heaviest at 24 to 28°C. Third, the prevention and control method 1? Rational rotation: with non-guatem crop rotation, is an important measure to prevent blight, the best rotation for more than 3 years, the seedbed to 2 to 3 years to change once. 2?Grafting control: Because cucumber wilt disease generally does not infect or only mildly infest other melon crops. Therefore, cucumber and other melon crops can be grafted. For example, sunflower seeds are used as rootstocks. Other disease resistant varieties of cucumbers are grafted for scion grafting. When grafted seedlings are planted, buried soil should be below the grafting interface to prevent intrusion of germs from the grafting interface. 3. Use disease-resistant seed varieties to cultivate disease-free strong seedlings: soak seeds in warm water at 55°C for 10 minutes before sowing or soak in seeds with 50% carbendazim and 70% thiophanate-methyl 500-fold for 1 hour, and sow germination after sowing. The use of nutritional seedlings can reduce pathogenic invasion. 4? Strengthen the cultivation and management, do a good job in field cleaning: Take small water ground irrigation, avoid flooding irrigation, increase phosphorus and potassium fertilizers, decomposed organic fertilizer, promote root development, and increase resistance to disease. Every time after picking melon water top dressing to prevent premature aging. Diseased plants were found, removed promptly, and destroyed centrally. The soil around the rhizosphere is disinfected with lime. 5? Chemical control: At the beginning of the disease, roots are irrigated with 400-500 mg/kg of 50% carbendazim WP or 800 mg/kg of 70% thiophanate-methyl wettable powder, 200-250 ml per drug solution. . Before the planting of the seriously diseased or seedbed soil, the soil was mixed with thiophanate-methyl or carbendazim at a ratio of 1:100, and 1.25 kg per mu was applied.

Best Body Composition Analyzer

Body Analyser,Body Element Analyser,Color Printing Analyser

Handsome Beauty Product Co., Limited , http://www.chinabeautyproduct.com