Why Are Tomatoes Rotting in Greenhouses
1. Selecting disease-resistant varieties
The varieties cultivated in
winter greenhouse should adopt excellent varieties with infinite growth, big fruit, cold resistance, shade resistance and disease resistance.
2. Apply organic fertilizer
Most of the soils prone to retting are sticky loam with poor air permeability. Organic fertilizer is not only rich in nutrition, but also can effectively improve soil aggregate structure, increase soil permeability and prevent diseases.
3. High temperature stuffy shed
Especially, there are many kinds of pathogenic bacteria in the soil of continuous cropping, so the high-temperature closed shed can kill bacteria and prevent diseases. The method is: 7 ~ 10 days before planting, turn the soil in the shed deeply by 20cm, spray carbendazim fungicide, cover the film to make the temperature in the shed reach 50 ~ 60℃, and close the shed for 5 ~ 7 days, and repeat it for 2 ~ 3 times.
4. The number and time of
watering Because of low temperature and less evaporation of soil moisture in winter greenhouses, watering should be properly controlled. Instead of flooding, one row can be watered every other row. The watering time should be controlled at the principle of late in the cold weather and prior in the warm weather. Water cannot be watered during the cold days or continuous cloudy days.
5. High temperature at night
The main limiting factor affecting vegetable production in warm shed in winter is night temperature, and the main way to increase night temperature is to thicken grass mats. The thickness is subject to the absence of light in the shed during the day. Double-layer film covering, that is, covering grass with a thin film at night, which can not only keep warm, but also protect grass from rain and snow erosion.
6. Sufficient ventilation and light transmission in the shed
In winter greenhouses, especially after watering (on the premise of ensuring the greenhouse temperature), ventilation and light transmission should be increased to reduce the humidity of air and soil in the greenhouse to prevent diseases.
7. Cropping for soil
If any vegetable is planted in the same plot for a long time, it will cause a large number of pathogenic bacteria to multiply, and it is an effective measure to prevent the occurrence of continuous cropping diseases.
8. Control of bacterial blight
At the early stage of the disease, 4000 times of 72% agricultural streptomycin, 500 times of 77% kocide wettable powder, or 500 times of 25% copper complex water were used to irrigate the roots, and each plant was treated with 300-500ml liquid medicine, once every 8-10 days, and continuously irrigated for 2-3 times.
9. Prevention and control of wilt disease
800 times of 70% thiophanate methyl wettable powder, 600 times of 50% carbendazim wettable powder, or 2000 times of 70% hymexazol wettable powder can be used for
root irrigation at the initial stage of disease, with 100mL of liquid medicine for each plant, once every 7 ~ 10 days, for 3 ~ 4 times continuously.
10. Prevention and control of rot
At the early stage of the disease, with 600 times of 72.2% Pulike aqua, or 500 times of 64% disinfectant alum wettable powder, 2500 ~ 3000 times of 97% hymexazol wettable powder, or 2000 times of 70% hymexazol wettable powder, each plant is irrigated with 100mL of liquid medicine, once every 7 ~ 10 days, continuously for 2 ~ 3 times.
11. Prevention and control of base rot
Spray the stem base and soil with 2500 ~ 3000 times of 97% hymexazol wettable powder or 1200 times of 20% methyl clozapine emulsifiable concentrate, or smear 200 times of pentachloronitrobenzene powder and 200 times of 50% thiram wettable powder to the diseased part. It is also possible to pile up 97% hymexazol wettable powder and naphthylacetic acid soil at the stem base, pile up at the base of diseased plant and bury the diseased part to promote it to grow adventitious roots above the diseased spot, which can prolong life for yield.