Bacterial damping-off and blight are the major diseases of cucumber during seedling stage.
symptom
In the early stage of the disease, the hypocotyls in the seedlings were infected with water-soaked spots on the surface of the hypocotyls. The cotyledon wilted at noon and recovered sooner or later. The diseased part of the seedlings later contracted, causing the cotyledon of the seedlings to lodge without being wilted. When the humidity is high, the diseased part produces white hyphae. . Blight usually occurs during the seedling stage and mainly affects the stem base or underground root of the seedlings. In the early stage, dark brown spots appear on the hypocotyl or base of the stem. The shape is nearly round or irregular, the disease part is sunken inward, and the whole stem is expanded after expansion. At the base, the stems are shriveled and dried, the above-ground leaves turn yellow, and the seedlings die, but they do not fall down. Most of the root damage is near the root neck of the surface, and the cortex is brown or rot. In the seedbed, the individual melon seedlings begin to wilt during the day and recover at night. After repeated days, the diseased plants are wilted and died of disease. The disease is similar to the disease in the early stage, but after the disease is expanded, the diseased plant does not reach the diseased area and the diseased area may have a ring vein or Not obvious light brown spider silk mold, the mycelia or sclerotia of the bacteria, and the slow progression of the disease, different from damping-off disease.
Prevention technology
(1) Choose no-soil soil seedlings or seed bed disinfection: Apply 50% seed dressing double powder 7 g/40% pentachloronitrobenzene powder, or 25% metalaxyl wettable powder per square meter seedbed 9g plus 70% mancozeb WP 1 g for 4~5 kg of fine soil, mix the bottom water of the seedbed before spraying, and take 1/3 of the drug soil on the surface after water infiltration. After sowing, 2/3 of the medicine soil is covered on the seed.
(2) Strengthen the cultivation and management: nursery crickets should choose lands with high topography, low groundwater level and well-drained land, avoid flood irrigation, and release air and remove moisture in time.
(3) Chemical control: In the initial stage of disease, 72.2% Preclosure 400 times or 25% metalaxyl WP 800 times. Use 2 to 3 times continuously.
Inner Mongolia Xuanda Food Co., Ltd. , https://www.xuandagroup.com