First, the coverage time should not be too long: the role of
Shade Net is shading, cooling, in the absence of strong light, the temperature is not high, shading nets can not always "sleep" in the greenhouse. Uncovering the shade nets requires a flexible grasp of the light intensity and temperature requirements according to the weather conditions, types of vegetables, and different growth periods of vegetables. Generally sunny cover, cloudy exposing; noon cover, sooner or later, exposing; pre-covered, late exposing. If there is more rainy weather and the temperature is not too high, after the vegetable is planted, the shade net can only be covered in the mild seedling period. If a black shading net is used, it will be covered only in the sunny midday. Sunshade net cover for a long time will affect the photosynthesis of vegetables and is not conducive to the normal results of vegetables. Therefore, shade nets should be covered only in the brightest part of the sunny day at noon. The specific time is from 10:30 am to 2:30 pm. If these measures are still difficult to reduce the temperature inside the shed, you can use spray or irrigation methods to cool down. In addition, spray 0.1% zinc sulfate or copper sulfate solution can enhance the plant's resistance to heat, anti-cracking, anti-sunburn ability. Second, the shade net and the shed membrane isolation: shade net close to the shed film, first, the heat it absorbs easily spread to the shed film and then spread to the shed, can not play a good shade net to reduce the effect of the shed temperature. Second, the heat can not be distributed, increasing the temperature of the shade net itself will accelerate the aging of the shade net. Therefore, when the vegetable growers cover the shade nets, they should put two winter soil-clad soil bags every 120cm on the bamboo poles. The front of the shed can be placed on the discarded grass curtains every 180-300cm. The purpose is to make the shade. The net is isolated from the shed film. In addition, the soil bag should not be placed on the shed film, so that the shed film will sink downwards, and it will not be able to support the shade net.
