What are the common diseases and insect pests of Chinese cabbage? How to make good prevention and control measures?

Chinese cabbage has a long history of cultivation in China, and it is the main vegetable in winter and spring in Northeast and North China. Vegetable leaves can be used for stir-frying, raw food, salting and pickling, and the outer layer of vegetable leaves can also be used as feed. However, because the cabbage is more hardy, like cold climate, such as high temperature, prone to diseases and insects. So, what are the common diseases and insect pests of Chinese cabbage? How to make good prevention and control measures?

What are the common diseases and insect pests of Chinese cabbage?

The common diseases of Chinese cabbage are soft rot, downy mildew, virus and so on, and the common pests are aphids, whitefly, cabbage worm, night moth and so on.

Second, how to control the common diseases and insect pests of Chinese cabbage?

1. Soft rot

The cultivation type of sowing in summer high temperature period (August-September) and the warm year in autumn occurred more frequently. In addition, the disease is more in low-lying land and less in highland and dry land. Overgrown plants with too much nitrogen fertilizer, flooded state and typhoon heavy rain caused damage to plants. Gramineae and legume crops should be cultivated for several years in the land with serious disease in order to reduce the density of pathogens. It can cultivate varieties with strong disease resistance, such as "Pingzhong No.1" and "thousand-year-old Chinese cabbage". Autumn sowing cabbage should focus on the control of pests such as yellow striped beetle and sugarcane black cricket. Improve the drainage conditions in the field and cultivate on the high bank. If the disease occurs, agricultural streptomycin can be sprayed once every 7 days for 2 or 3 times in a row.

2. Downy mildew

Select disease-resistant varieties; avoid too dry or wet topsoil, timely fertilization, especially to increase the application of phosphorus and potassium fertilizer to enhance plant disease resistance; early disease can pull out the central diseased plants, when the disease is common, the diseased leaves and seriously diseased plants can be cleared out of the field as soon as possible, and do harmless treatment in time. The medicament can be sprayed once every 5-7 days, such as 40% triethyl phosphonate aluminum (ethyl phosphorus aluminum) wettable powder 200 times liquid, 70% ethyl phosphorus aluminum manganese zinc wettable powder 500 times liquid, etc. The occurrence of downy mildew is closely related to virus diseases, so the two diseases should be considered in order to get a good control effect. Chinese cabbage virus disease is transmitted by aphids, so early prevention and control of aphids should be done.

3. Virus disease

Select disease-resistant varieties; strengthen field management, first of all, deep ploughing, thorough removal of weeds on the edge of the field. Secondly, the diseased plants should be pulled out in time, taken out of the field and buried or burned, which can reduce the source of poison and reduce the disease. If the disease has occurred, the medicament can be sprayed with 500 times of virus A wettable powder, or 0.5% of antiviral agent 1, 300 times of water, or 20% of virus net 500 times, or 20% of virus A500 times. Spray once every 5-7 days, 2-3 times in a row.

4. Insect pests

(1) Agricultural prevention and control

Select excellent varieties, cultivate strong seedlings, sow in time, crop rotation, strengthen management, clean the countryside and so on.

(2) physical control

Yellow armyworm board was used to trap and kill aphids, whitefly and other pests.

Sweet and sour liquid trapping: sweet and sour liquid is prepared with 3 parts of sugar, 3 parts of vinegar, 1 part of high liquor, 10 parts of water, and then 0.1 parts of 90% crystal trichlorfon, evenly placed in a large bowl, 1 part per 80m2, cover during the day, open at night, and change the sweet and sour solution once in 10-15 days.

(3) Biological control

Release natural enemies, such as predatory mites and parasitic wasps, use biological pesticides such as Bacillus thuringiensis and avermectin, and apply biological fertilizer indole.

(4) Chemical control

Aphids and whiteflies use 10% imidacloprid wettable powder 1000-1500 times or 10% acetamiprid 1000-1500 times alternately, spray 2-3 times, and pay attention to spraying the back of the leaves. Pieris rapae and Spodoptera litura were alternately sprayed with 2.5% cypermethrin 2000 times or 4.7% cyhalothrin 3000 times before the 3rd instar. Downy mildew was treated with 1500 times solution of 25% dialkynyl amide suspension or 72% urea manganese zinc wettable powder, which was used in rotation, sprayed once in 7-10 days, and prevented for 2-3 times. Soft rot was sprayed with 72% agricultural streptomycin sulfate wettable powder 4000 times or 3% Zhongshengxin wettable powder 1000 times.

For the common diseases and insect pests of Chinese cabbage, prevention is the main, giving priority to agricultural control, physical control, biological control, combined with chemical control.