Downy mildew and soft rot are two common diseases in the growth of Chinese cabbage. Their external performance is similar. Pay attention to the difference.
First, performance symptoms:
1. Soft Rot Disease: After onset, the outer leaves are wilting and the Chinese cabbage wilts at noon on sunny days. However, it can be restored sooner or later. After a few days, the outer leaves of the plants are flat on the ground, the rear leaves of the heart are exposed, and the marrow rots on the petiole or rhizome. The grayish-brown viscous material can flow out, and the plant rots after falling to the ground.
2. Downy mildew: damage during the seedling period, can be seen in the sunny morning on the back of the leaves have a white layer of mildew, severe yellow seedlings die when dead. In the adult phase, the leaves develop water-stained, light-green spots in the early stages of the front, and then expand. They become yellow to yellow-brown polygons due to the limitation of the veins. When wet, white moldy layers grow on the back of the leaves. Call it white mold. In severe cases, the lesions quickly developed into patches, causing the leaves to die and die. In addition to damaging the leaves, seedlings can also harm pedicels, flower organs, and seed pods. The victim's pedicel was swollen and bent; the affected flower organ was hypertrophic and deformed, and the petals became green; the affected species were light yellow, with white mold, thin and weak seedpods, or poor fruiting.
Second, control methods:
1. Physical control: Whether it is cabbage downy mildew or soft rot disease, should be reasonable irrigation and fertilization, deep tillage soil, full base fertilizer, stage application of phosphorus, potash fertilizer; timely cultivator, promote plant root growth, enhance disease resistance Sex.
2. Drug control:
(1) Prevention and control of cabbage downy mildew: When the central diseased plant was found at the early stage of disease, the diseased petiole was immediately removed for prevention and treatment. Pharmacy can choose 65% chlorothalonil 600 times liquid +2000 times love to receive more or 20% sodium dichloroisocyanurate 1000-1500 times, 64% can also be used to kill 600 times or 25% Wettable powder 800 times or 70% mancozeb 500 times. Spray once every 7-10 days and spray 2-3 times.
(2) Chinese cabbage soft rot should be mainly prevention and integrated prevention and treatment. After planting, in the Chinese cabbage rosette period to the beginning of Baoxin, 72% agricultural streptomycin 3000-4000 times liquid, 20% Jinggangmycin aqueous solution (25 grams per bag) were used to water 50 kg, 200-300 times vinegar, Spray once every 7-10 days and spray 2-3 times.