Management techniques of Chinese cabbage in heart stage

The water consumption of Chinese cabbage entering the core stage is larger than that in the early stage, so it must be irrigated and replenished, keep water uniform and adequate supply, and avoid more and less, dry and wet. The specific requirements are: the first water in the heart period should be small, the amount of water is too large to cause plant growth damage; the first water in the heart will enter normal irrigation after 5 days, generally 5 times a day, one water for 7 days, each irrigation volume is not less than 30 square; stop watering a week before chopping vegetables, one is to avoid excessive water and storage, the other is to facilitate harvesting and reduce losses caused by mechanical damage.

Topdressing in the heart stage should mainly be applied with water, the first topdressing was applied in front of Cold Dew, and the second topdressing was applied a few days before Frosts Descent. During this period, the temperature decreased gradually, and quick-acting nitrogen fertilizer should be used as the main fertilizer, ammonium sulfate was generally selected, 20ml / mu and 30kg per mu was suitable, followed by water application. The amount of topdressing should be increased appropriately for the plots with slightly poor enclosing degree. In the later stage, we should stop topdressing so as not to overgrow Chinese cabbage.

Pest control. The use of Chinese cabbage should be stopped half a month before harvest. Chinese cabbage should focus on the control of downy mildew, black spot, soft rot, black rot, bacterial angular spot, aphids, cabbage beetle, beet armyworm and so on. It is required to use symptomatic medicine, prevention and treatment in a scientific and timely manner. The spray should be considerate and meticulous, and it is appropriate to spray both the front and back of the leaves. Chemical control is combined with physical control, where possible, insecticidal lamps or yellow boards can be used to trap and control insect pests.

Specific medication:

(1) Disease control: downy mildew: 72% frost urea manganese zinc wettable powder 600ml 800 times liquid; or 69% Anke manganese zinc wettable powder 800ml 1000 times liquid; or 72% Kelou wettable powder 600 times solution spray control. Black spot: spray control with 1000 times of 50% prohydantoin wettable powder or 800 times of 600 times of 80% Dasheng wettable powder. Soft rot, black rot: 72% agricultural streptomycin 4000 times solution or 77% wettable powder solution can be used. It is found that the diseased plants of soft rot and black rot should be removed in time, taken out of the field and buried deeply, and the disease holes should be disinfected with quicklime or medicament, and compacted with soil to prevent the spread of germs after watering or rain. Bacterial angular spot can be controlled with 4000-fold solution of neophytomycin.

(2) Pest control: 1.8% avermectin 3000 times solution can be used to control beet armyworm; 2.5% vegetable like suspension 1000ml 1500 times solution can be used to control Plutella xylostella and Pieris rapae; snail nemesis can be used to control snails.