A Detailed Guide to Identifying and Controlling Common Pests and Diseases of Chinese Cabbage

Chinese cabbage has a long history of cultivation in China and is a major vegetable for winter and spring in Northeast and North China. The leaves can be stir-fried, eaten raw, salted, or pickled in sauce, and the outer fallen leaves can still be used as feed. However, because Chinese cabbage is relatively cold-tolerant and prefers a cool climate, when it encounters high temperatures, it is prone to pests and diseases. So, what are the common pests and diseases of Chinese cabbage? How can control measures be carried out well?

1. What are the common pests and diseases of Chinese cabbage?

Common diseases of Chinese cabbage include soft rot, downy mildew, and viral disease; common pests include aphids, whiteflies, cabbage caterpillars, and noctuid moths.

2. How can control measures be carried out well for the common pests and diseases of Chinese cabbage?

1. Soft rot

It occurs more often in the cultivation type sown during the high-temperature summer period (August—September) and in warm autumn years. In addition, it occurs more in low-lying land and less in highland and dry land. Plants with excessive nitrogen fertilizer and spindly growth, in waterlogged conditions, and damaged by typhoons and heavy rain develop the disease. In severely affected plots, gramineous and leguminous crops should be cultivated for several years to reduce the density of the pathogen. Disease-resistant varieties such as “Pingzhong No. 1” and “Qiansui Chinese Cabbage” can be cultivated. For autumn-sown Chinese cabbage, key control should target pests such as the striped flea beetle and the sugarcane black cricket. Improve field drainage conditions and use raised-bed cultivation. If the disease occurs, agricultural streptomycin can be sprayed for control, once every 7 days, for 2 to 3 consecutive times.

2. Downy mildew

Choose disease-resistant varieties; avoid the topsoil being too dry or too wet, fertilize in time, and especially increase the application of phosphorus and potassium fertilizers to enhance the disease resistance of the plants; in the early stage of disease, the central diseased plants can be removed, and when the disease is widespread, the diseased leaves and severely diseased plants should be cleared out of the field as soon as possible and promptly subjected to harmless treatment. For chemical control, 40% fosetyl-aluminum wettable powder at 200 to 300 times dilution, 70% fosetyl-aluminum manganese zinc wettable powder at 500 times dilution, etc. can be selected, sprayed once every 5 to 7 days. The occurrence of downy mildew is closely related to viral disease, so when controlling them, these two diseases should be considered together in order to achieve good control results. Chinese cabbage viral disease is transmitted by aphids, so early control of aphids should be carried out well.

3. Viral disease

Select disease-resistant varieties; strengthen field management. First, plow deeply and cultivate carefully, and thoroughly remove weeds at the edges of the field. Second, diseased plants should be pulled out in time, taken out of the field, and deeply buried or burned, which can reduce the source of the virus and lessen the disease. If the disease has already occurred, chemical control can use Virus A wettable powder at 500 times dilution, or 0.5% antiviral agent No. 1 aqueous solution at 300 times dilution, or 20% Bingdujing at 500 times dilution, or 20% Virus A at 500 times dilution and other agents for spraying. Spray once every 5 to 7 days, for 2 to 3 consecutive times.

4. Pests

(1) Agricultural control

Select excellent varieties, cultivate strong seedlings, sow at the right time, rotate crops, strengthen management, and keep the garden clean, etc.

(2) Physical control

Use yellow sticky insect boards to trap and kill pests such as aphids and whiteflies.

Sugar-vinegar liquid trapping: the sugar-vinegar liquid is prepared with 3 parts sugar, 3 parts vinegar, 1 part high-proof liquor, add 10 parts water, then add 0.1 part 90% crystallized trichlorfon, mix well and put into a large bowl, place 1 bowl per 80 sq m, cover during the day, open at night, and replace the sugar-vinegar liquid once every 10-15 d.

(3) Biological control

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

(4) Chemical control

For aphids and whiteflies, use 10% imidacloprid wettable powder at 1000-1500 times dilution, or 10% acetamiprid at 1000-1500 times dilution alternately, spray 2-3 times, and be sure to spray the underside of the leaves. For cabbage caterpillars and noctuid moths, before the 3rd instar, use 2.5% beta-cypermethrin at 2000 times dilution, or 4.7% lambda-cyhalothrin at 3000 times dilution, and spray alternately. For downy mildew, use 25% mandipropamid suspension concentrate at 1500 times dilution, or 72% cymoxanil mancozeb wettable powder at 600-800 times dilution, use them in rotation, spray once every 7-10 d, for 2-3 consecutive control applications. For soft rot, use 72% agricultural streptomycin sulfate wettable powder at 4000 times dilution, or 3% zhongshengmycin wettable powder at 1000 times dilution for spray control.

For the common pests and diseases of Chinese cabbage, the main approach is prevention first, giving priority to agricultural control, physical control, and biological control, in combination with chemical control.