Control method for heartburn of Chinese cabbage with yellow leaf edge and rotten leaf meat

Dry burn heart disease of Chinese cabbage, also known as dry heart disease, is a physiological disease, which occurs in the middle and late growth of Chinese cabbage and is one of the most important diseases of Chinese cabbage.

Dry burning heart disease of Chinese cabbage

Symptoms and causes:

The typical symptoms are: the outer leaf grows normally. After the bulb is cut open, part of the edge of the heart leaf turns white, yellow and dry, and the mesophyll is dry and low. Chinese cabbage with heartburn is susceptible to soft rot, severe decay and bad smell. The cause of dry burn heart disease of Chinese cabbage is physiological deficiency of calcium or manganese, while physiological deficiency of calcium is caused by dry weather, uneven watering, salinity and excessive nitrogen fertilizer. The methods of prevention and control:

1. Disease-resistant (tolerant) varieties were selected. Chinese cabbage varieties with disease resistance or disease tolerance should be selected in accordance with local conditions. Such as Beijing Qingqing, Tanggu big walnut pattern, Tianjin Xinhezhong walnut pattern, Zhongbai No. 4, Dalian Qingza Zhongfeng and so on.

two。 Choose a suitable garden field. The fields with fertile soil and low salt content should be selected, and the specific requirements are as follows: the content of organic matter in vegetable soil should be more than 3%, the content of total salt should be less than 0.2%, and the content of sodium chloride should be less than 0.05%.

3. Scientific management of water. Water should be watered thoroughly before sowing, small water should be watered frequently at the seedling stage, and the rosette period should be appropriately squatted according to the weather, moisture and growth, and the weather is dry, but not squatting seedlings. After squatting seedlings, you should pour enough water for 1 time and keep it moist during the pericardium period. After irrigation, ploughing in time to prevent soil consolidation and salinity rise. Avoid watering the fields with sewage and salt water.

4. adequate manuring. For the soil with long-term use of ammonia nitrogen, it is necessary to increase the application of farm fertilizer, apply sufficient basic fertilizer in deep ploughing, improve water conservation and fertility, improve soil structure, and control the amount of nitrogen fertilizer according to soil fertility, generally 240-60 kg per mu; at the same time, it is necessary to increase the application of phosphorus and potassium fertilizer.

5. Supplement calcitonin. In acidic soil, lime can be added properly and pH can be adjusted to facilitate the absorption of calcium by Chinese cabbage roots. At the end of rosette stage of Chinese cabbage, 3-4 grams of granular fertilizer or sub-calcium fertilizer can be applied to each heart leaf. The mixture of 0.7% calcium chloride and 50 mg / kg naphthalene acetic acid can also be sprayed on heart leaves from the middle of rosette, once every 7-10 days, continuously spraying 4-5 times, that is, it has the effect of preventing and curing dry burning heart disease of Chinese cabbage.