How to effectively prevent celery spot blight
First, the symptoms of celery spot blight mainly harm the leaves, followed by the petiole and stem. Old leaves first onset, from the outside to the inside. The lesion is initially a small spot with a light brown oily immersion. The edge is obvious. Later, it develops into irregular spots. The color changes from light yellow to grayish white, the edge is dark reddish brown, and many small black particles are gathered. There is often a yellow circle outside the lesion. Halo. The petiole and stem are brown, the oblong is slightly sunken, and the black spots are scattered in the middle.
Second, the incidence of celery spot blight is a fungal disease, low temperature and high humidity is conducive to the occurrence of the disease, the most suitable temperature for the disease is 20-25 ° C, humidity is more than 95%, in the deep winter season, even Yin Frequent fluctuations in temperature, daytime heat fluctuations, nighttime condensation, weak plant growth, more irrigation, and untimely ventilation and drainage can often lead to rapid spread of disease.
Third, the prevention and treatment methods 1, balanced fertilization of the base fertilizer should be applied adequate, decomposed organic fertilizer, fertilizer should be added to the application of phosphorus and potassium fertilizer, control the amount of nitrogen fertilizer, try to spray some foliar fertilizer and micro-fertilizer to enhance plant resistance.
2, cooling and dehumidification during the daytime temperature control at 15-20 ° C, more than 20 ° C when the wind should be released in time, night control at 10-15 ° C, reduce the temperature difference between day and night, reduce condensation, not flooding.
3, 45% chlorothalonil smog or smog smog smog for pharmacy control, scatter at 5-6 per acre 150 grams, fumigation 1 night, once every 10 days. In the early stage of the disease, spray 70% of the mancozeb WP 600 times solution, or 50% of the carbendazim WP 600-800 times solution, once every 7-10 days, continuous spraying 2-3 times is very good. The preventive and therapeutic effects.
4. Clearing the diseased plants in time For the sheds that have already occurred, it is necessary to promptly remove the residuals of the diseased plants in the room and reduce the spread and spread of the bacterial sources.