How to control the soft rot of cabbage after wrapping leaf rot and then leaf ball rot

Cabbage soft rot usually occurs in the heading stage, and water-immersed spots begin to appear at the base of the outer leaf or bulb, and the outer leaves wilt at noon and recover sooner or later, but no longer recover after a few days, the disease begins to rot, the leaf ball is exposed or the base of cabbage gradually rotts into mud, or collapses and fester, the tissue at the base of petiole or rhizome is grayish brown and soft rot, severe whole plant rot, and the disease stinks.

Cabbage soft rot

The pathogen of soft rot overwinters in the tissue of diseased cabbage. Germs invaded from the wound, including natural cracks, insect injuries, disease injuries and mechanical injuries, of which the highest incidence was natural cracks in the petiole, followed by insect injuries. The natural cracks are mainly longitudinal cracks, which mostly occur after a long period of drought and rainfall, and the pathogens develop rapidly and lose a lot after the invasion of cabbage petiole cracks. After the heart is full of rain, the disease is often serious.

Prevention and control methods:

1 agricultural measures. Early ploughing and soil preparation can improve soil properties, increase fertility and soil temperature, and promote decay and decomposition of cabbage disease and residues. Using ridge cultivation or high border cultivation which is beneficial to drainage and waterlogging prevention, the disease is light. Increase the application of base fertilizer and topdressing in time. Lack of water and fertilizer in the seedling stage, poor growth, rainy in the later stage, it is easy to produce natural cracks in the petiole. Sufficient base fertilizer and early topdressing make the seedling grow vigorously, and in the later stage, the plant is resistant to water and fertilizer, and the natural crack is less, so the control effect is more significant.

Early sowing is easy to make the susceptible stage of cabbage pericardium meet with the rainy season, the disease is serious, and the pericardium period of late sowing is delayed, which is beneficial to disease prevention. However, if it is too late and affects the yield, the suitable sowing date should be controlled according to the characteristics of varieties, climate, irrigation and so on.

If seriously diseased plants are found in the field, they should be harvested or pulled out in time to reduce the source of bacteria and prevent spread. Especially before heavy rain and irrigation, check and deal with it. After removal, the acupoint can be filled with lime for sterilization.

(2) Chemical control. Early attention should be paid to the control of underground pests. From the seedling stage, it is necessary to control pests such as jumper beetle, cabbage worm, Plutella xylostella, ape leaf insect and so on.

Before or at the initial stage of the disease, spraying agents can be used to prevent the spread of the disease. Spraying should focus on lightly diseased plants and their surrounding cabbage, and pay attention to spraying on the petiole and stem base of cabbage close to the surface. Commonly used medicament: agricultural streptomycin 200 ppm; Dexon powder 500 Mel 1000 times liquid; 50% Dysenamine 600 Mel 800 times liquid and so on.