When high temperature strikes, how can greenhouse vegetables cool down scientifically?


2023-02-18 11:14

Recently, high temperature and heat waves have hit many parts of the country, and the long duration and intensity are rare in the same period.

In such high temperature weather, we need air conditioners and fans to "continue life", and greenhouse vegetables are also in urgent need of cooling. There are many cooling methods commonly used by vegetable farmers, but in practical applications, there are common misunderstandings. How can cooling be more scientific and effective?



Shading net covering method should be scientific


  • The sunshade net is best not to stick to the shed surface

The black shading net absorbs a lot of heat, which will directly transfer the heat to the shed film and shorten the life of the shed film.

Correct use method: It is recommended to keep a distance of 0.5 to 1 meter between the shading net and the shed surface to ensure that the air can flow between the shading net and the shed surface, which can not only accelerate the heat loss in the shed, but also have a good shading effect and reduce the shedding. Body heat storage.

Practice has proved that the temperature in the former shed is more than 5 ℃ lower than that of the latter when the shade net and the shed film are set at intervals compared with the close-fitting setting. When a single greenhouse is covered with a sunshade net, the vegetable farmer can place two soil bags with film on the steel frame structure or large bamboo poles at a certain distance, and the front of the shed can be placed at a certain distance with the discarded straw thatch pads.

For bases or parks, where greenhouses are relatively concentrated, automated shading equipment can be used. When setting up, pre-set steel pipe brackets on the back wall, gables on both sides and front face of the greenhouse, about 1 meter away from the shed surface, add steel wires on the shed surface, cover the shading nets on the steel wires, and set up support nets at intervals of 0.5 meters rope for fixing the shade net.

Finally, install the machine head on the steel pipe on the front face in the middle of the greenhouse, so that you only need to hold the remote control and press the button to easily complete the pulling and placing of the sunshade net. At the same time, the shading area can be flexibly adjusted according to the weather conditions.


  • Shading time should not be too long

If the shade net is covered for too long, it will affect the photosynthesis of vegetables, which is not conducive to the normal growth of vegetables. Vegetable shading should be flexibly controlled according to the weather conditions, vegetable types and the requirements of light intensity and temperature in the vegetable growth stage.

Materials used for shading, such as shading nets, are generally covered on sunny days and uncovered on cloudy days; covered at noon and uncovered in the morning and evening; covered in the early stage and uncovered in the later stage of growth. If the weather is cloudy and rainy and the temperature is not too high, after the vegetables are planted, the shading material can only be covered in the slow seedling period. In addition, when it is cloudy for a long time or when root diseases occur, vegetable farmers can also use sunshade nets to avoid the occurrence of plant wilting.



Greenhouse cooling agent should be used properly


  • Preparation


Clean the dust off the shed film before spraying. The easiest and most efficient way is to find a long sweeper, wrap the cotton wick in the thermal insulation quilt or soft old clothes on the sweeper, and tie it tightly with cloth strips. Be careful not to use iron wire to prevent scratching the shed film.

Special reminder: The weather is fine after rain, and the cooling agent spraying effect is the best, which can save the work of manually cleaning the dust of the shed film.


  • Dosage


When using, refer to the product description and dilute with water according to the required shade rate.

It should be noted that the cooling agent should be turned upside down and shaken well before opening the lid to prevent precipitation. When diluting, you can first add a small amount of water to the bottom of the sprayer, add a cooling agent, and finally fill up the water. Then close the sprayer cap and shake well. It is also possible to dilute the cooling agent in proportion with a bucket first, then transfer it to the sprayer, and then spray it upwards in sections from the bottom of the greenhouse.



  • Precautions

1. When you need to operate on the roof, you must pay attention to safety. ​​

2. It is recommended to spray in sunny and windless weather. ​​

3. The cooling agent must be diluted with clean water, and it must be used and prepared now. ​​

4. After spraying, clean the sprayer with clean water in time. ​​

5. Using an electric sprayer, the better the atomization effect of the nozzle, the higher the quality of spraying. ​​

6. When spraying, the nozzle should not be too close to the shed film, and the swing range can be slightly larger to prevent dripping. Do your best not to leak or re-spray. ​​

7. For greenhouses without roller shutters, the nozzles of the sprayer can be bundled and lengthened with bamboo poles. Then the shed film is divided into upper and lower sections for spraying construction operations. ​​

8. When spraying the cooling agent, pay attention to closing the top tuyere to prevent the cooling agent from dripping on the leaves.


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