How to sterilize and disinfect a greenhouse by high-temperature sealing? Detailed methods
How do you sterilize and disinfect using the high-temperature greenhouse sealing method? Please explain the high-temperature greenhouse sealing disinfection method, which is to seal the greenhouse in summer and use the high temperature from solar heat and chemical fumigation to disinfect inside the greenhouse, generally carried out from early July to late August. This method has low cost, little pollution, simple operation, good results, and is easily accepted by people...
How do you sterilize and disinfect using the high-temperature greenhouse sealing method? Please explain
The high-temperature greenhouse sealing disinfection method is to seal the greenhouse in summer and use the high temperature from solar heat and chemical fumigation to disinfect inside the greenhouse, generally carried out from early July to late August. This method has low cost, little pollution, simple operation, good results, and is easily accepted by people. The specific method is as follows:
1. Land preparation and fertilization: The land should be leveled and finely prepared, and fertilization should be combined with land preparation to kill pathogens in organic fertilizer. Some organic fertilizers such as chicken manure and dried cow manure also help raise the ground temperature and maintain it, making the sterilization effect better. After the land is prepared, ridges should be made or high and low beds should be formed according to the crop planting method, so that a small space is formed between the plastic film and the ground, which helps raise the ground temperature.
2. Irrigation: The soil moisture content is closely related to the sterilization effect. If the soil moisture content is too high, it is unfavorable for raising the ground temperature; if the soil moisture content is too low, a good sterilization effect cannot be achieved. Practice has shown that the best effect is achieved when the soil moisture content reaches 60% of the field maximum water-holding capacity.
3. Chemical treatment: Use chloropicrin for soil disinfection under plastic film mulching to kill pathogens in the soil. The method is to inject chloropicrin into the bed, digging one hole every 50 square cm, with a depth of 10-15 cm, and 4 ml per hole. In addition, before sealing the greenhouse, spray the inner surface of the greenhouse once with a fungicide and insecticide to kill pathogens and pests hiding in wall cracks.
4. Sealing the greenhouse: Use greenhouse film and plastic film for double-layer covering, strictly maintaining the airtightness of the greenhouse. Under such conditions, the maximum ground temperature at 10 cm below the surface can reach 70°C, and the ground temperature at 20 cm can reach above 45°C. Such high ground temperature can achieve a sterilization rate of more than 80%.
5. Disinfection time: The vast majority of pathogens cannot tolerate high temperatures and can be killed after a very short period of heat treatment (about 10 days), such as some damping-off pathogens, cucumber sclerotinia pathogen, cucumber phytophthora blight pathogen, eggplant verticillium wilt pathogen, etc. However, some pathogens are particularly heat-tolerant, such as root rot pathogen, clubroot pathogen, and fusarium wilt pathogen and other deep-rooted soil-borne pathogens. Because they are distributed in deeper soil layers, they must be treated for 30-50 days to achieve a good effect. Therefore, when disinfecting soil, the disinfection time should be determined according to the crops planted in the greenhouse and the heat resistance of their corresponding pathogens.
6. Post-disinfection treatment: Solar heat disinfection works best on soil no deeper than 15 cm, and has a poorer disinfection effect on soil deeper than 20 cm. Therefore, after soil disinfection, it is best not to plow or turn the soil again, and even if it is plowed or turned, it should be limited to a depth of 10 cm. Otherwise, pathogens from the lower soil will be brought back up, causing recontamination. Although the solar heat disinfection method cannot completely sterilize the greenhouse, it can greatly reduce the pathogen density in the field and greatly reduce the chance of crop disease. Its disinfection effect can last for 2 years, so the greenhouse can be disinfected once every 2 years.
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