Occurrence and Control of Physalis Cristatum

First, the harm symptoms: after the onset of Celosia, seedling stem base or underground root water spots oval or not dark spots, gradually sag, the edge is more obvious, when the lesions expand around the stem one week, the stem above the dry death Generally not broken, it is called blight. It is not easy to distinguish from damping-off disease in the early stages. At the early stage of disease, individual plants wilted during the day and recovered at night. The disease spread slowly, and the course of disease was longer. After the overthrow of the disease, the individual fell down immediately. In addition, the blight disease department often has no obvious gray-to-grey spider silky mildew. When the humidity is high, it often grows gray-brown or gray-white pellicles, that is, borne burdens and basidiospores, which are different from damping-off disease. Second, the morphological characteristics of pathogens: The disease caused by the bacteria is a non-spore-forming filamentous fungi, its mycelium morphology and some ascomycetes, basidiomycetes are very close, a hyphae fusion phenomenon. With mycelium or sclerotium in the soil in winter, and can be rot in the soil for 2-3 years. After the winter, the mycelial reactivation activity and the sclerotia germinate to produce hyphae that contacted the host, causing initial infection. After the onset of disease, the aerial hyphae produced by the Minister of Disease actively contacted the host or was re-infected through the flow of water and agricultural tools. Germ development temperature 24 °C, the highest 40-42 °C, the lowest 13-15 °C, suitable for pH 3-9.5. Sowing too dense, not timely between the seedlings, the temperature is too high to induce the disease. Third, the prevention and control methods: (1) meticulous care to prevent seedling plate or seedbed high temperature and high humidity conditions. (2) Seedling tray or bed soil treatment. 40% of the seedlings were mixed with 50% of thiram and mixed with 1:1 to apply 8 grams per square meter of seedbed. Bacterial blight alone area with seed dressing spirit control effect is not high, need to be mixed into the same amount of the United States can be effective. It is also possible to use 95% green hen No. 1 fine 3000 times liquid. (3) In the initial stage of onset of spraying, 20% methyl-rhodamine emulsifiable concentrate (Likegar) 1000 times solution or 95% Luhuiheng No. 1 fine 3000 times solution or 10% Lycopene aqueous solution 300 times, 50% Net wettable powder 900 times, 2-3 liters per square meter. When the blight and damping-off diseases were mixed, spray 72.2% Preclosure 800 times with 50% thiram WP 800 times, 2-3 liters per square meter. (4) Biological control. Antagonistic microorganisms are used for biological control. The use of Wu's pig manure to cultivate antagonistic bacteria for soil, seed and reproductive tissue processing can also prevent and treat the disease. In addition, the application of green Trichoderma preparations can also effectively control the disease.