Matters needing attention when the germicidal effect can not be achieved in the greenhouse at high temperature.

Summer season, with high temperature stuffy shed, can eliminate germs, kill eggs, remove weeds, improve soil. The so-called high-temperature greenhouse is to disinfect the vegetable greenhouse with the high temperature of the sun and drug fumigation from late June to mid-late July. Attention should be paid to the greenhouse. Some vegetable farmers do not pay attention to the details of the greenhouse, so the effect cannot be achieved. Precautions for high temperature vegetable greenhouses:

greenhouse

1. Combined soil preparation, deep ploughing and fertilization

The ground should be leveled, trimmed, deeply ploughed and fertilized. Combined with soil preparation, organic fertilizers such as chicken manure and pig manure are deeply ploughed into the ground to kill germ eggs in the organic fertilizer by high temperature. After deep ploughing and leveling, ridging or making high and low ridges according to the planting method of vegetables, so that a small space is formed between the plastic film and the ground, which can enhance the sterilization effect.

II. Drug treatment, sterilization and insecticide

For greenhouses with dead vegetables in previous years, 2~3 kg of carbendazim or 60-100 kg of lime nitrogen can be used per mu, scattered on the ground, deeply ploughed 10~15cm, covered with plastic film, disinfected the soil and killed germs. In addition, before sealing the greenhouse, carbendazim fungicides and pesticides are sprayed on the inner surface of the greenhouse again to kill germs and pests hiding in the cracks.

Third, sufficient water irrigation, increase humidity

Soil moisture content is closely related to sterilization effect. Practice has proved that soil moisture content is too low to achieve good sterilization effect. The effect is best when the soil moisture content reaches 60% of the maximum field water holding capacity, and the irrigation water surface is 3~5cm higher than the ground.

IV. Closed greenhouse to increase ground temperature

Greenhouse film, plastic film, double coverage, to maintain the tightness of vegetable greenhouse, this treatment method, can make the highest temperature of 10cm below the surface of the ground up to 70℃, 20cm of the ground temperature up to 45℃ above, such a high ground temperature, sterilization rate of more than 80%.

5. Appropriately extend the time of closed shed

The vast majority of bacteria are not resistant to high temperature, after more than 10 days of heat treatment can be killed, such as some blight, cucumber sclerotiorum, cucumber blight, eggplant verticillium wilt and other high temperature resistance. However, some pathogens are particularly resistant to high temperatures, such as root rot, root swelling and fusarium wilt, etc. Some deep-rooted soil-borne pathogens must be treated for 30 to 50 days to achieve better results due to their deep distribution of soil layers. Therefore, when soil disinfection is carried out, the disinfection time should be determined according to the heat resistance of the vegetables planted in the shed and their corresponding germs.

VI. Treatment after closed shed

The greenhouse high temperature stuffy shed has the best effect on the soil with a depth of no more than 15cm, and the effect on the soil with a depth of more than 20cm is poor. Therefore, after soil disinfection, do not plough again. Even if ploughing, the depth should also be limited to 10cm. Otherwise, the germs in the soil below will be turned up and re-contamination will occur. The high temperature covered shed can greatly reduce the pathogen density in the field and greatly reduce the chance of vegetable disease.