In the cultivation of vegetables, farmers will take a variety of ways to avoid the unfavorable environment, farmers use sun protection nets for plants frequently to reduce the temperature in hot climates. Correct ways are as follows.
There are black and silver gray sun protection nets for plants on the market. The shading rate of black nets is high, with good cooling effect, but their impact on photosynthesis is greater. It is more suitable for leafy vegetables, so you should reduce their coverage time if used on some light-loving vegetables. As the cooling effect is not as good as the black, the impact of silver gray sun protection nets for plants on the photosynthesis is smaller, so they can be used in solanaceous vegetables and other light-loving vegetables.
There are two kinds of sun protection nets covering methods: all covering and pavilion-type covering. In practical application, pavilion-type covering is used more because of better cooling effect and free ventilation airflow. The specific method is: covering the net on the top by using the skeleton of the arch shed, leaving 60-80 cm venting band on it. If covered with films, you should leave a gap of more than 20 cm for wind cooling and sun protection nets for plants can not be covered directly on the film.
Although it can decrease the temperature, but at the same time also reduces the light intensity, which has a negative impact on the photosynthesis of vegetables. So coverage time is also very important, and nets can be covered between 10:00 am and 4:00 pm according to the temperature. When the temperature drops to 30 ℃, you can remove sun protection nets. To minimize the adverse effects on vegetables, do not cover on cloudy days.