How to achieve high yields of greenhouse vegetables in summer? These 5 points are important
High summer temperatures cause pests and diseases to increase, and vegetable growth is also restricted to a certain extent. At this time, if you want to ensure vegetable yields, you need to learn to use some seed techniques. So what are the high-yield techniques for greenhouse vegetables in summer? Doing these 5 points well is important!
High-yield techniques for greenhouse vegetables in summer
1. Ensure natural ventilation
To avoid vegetables in the greenhouse being affected by high temperatures, pay attention to opening all the upper and lower ventilation openings of the greenhouse, so that cold air outside the greenhouse enters and forms convection with the hot air inside, accelerating the discharge of hot air and thus lowering the temperature inside the greenhouse.
2. Use shade nets to cool down
Shading can block excess sunlight outside, protect crops from being scorched by strong light, and create suitable growing conditions for crops. At present, when using black shade nets, note that they must not be used for coverage all day, so as to avoid forming a low-light environment inside the greenhouse, which is not conducive to vegetable growth. Black shade nets should be used between 10 o'clock and 14 o'clock. When setting up the shade net, it can be propped up to leave a gap with the greenhouse film, forming a ventilation belt, and the shading and cooling effect is better. However, note that when lowering the shade net, do not block the ventilation openings.
When purchasing a shade net, choose one with a shading rate of about 60%. This kind of shade net can both shade and cool, and also allow part of the light to reach the inside of the greenhouse, which is very helpful for photosynthesis in vegetable leaves.
3. Spray at the right time
At noon in summer, the temperature inside the greenhouse is relatively high, leaf water evaporation is large, and the water absorbed by the root system cannot meet the needs of vegetable water evaporation, causing vegetable leaves to curl upward. Spray nozzles can be installed inside the greenhouse to lower the greenhouse temperature by spraying. This can also increase the air humidity inside the greenhouse, prevent the stigma of vegetable flowers from drying out, promote pollination, and prevent vegetable flower and fruit drop.
4. Install insect-proof nets
Some growers are only used to setting up insect-proof nets at the front face of the greenhouse or on both sides of the arched shed, but often ignore the top ventilation openings, which provides convenient conditions for the invasion of pests. In this case, it is very conducive to virus-transmitting pests spreading viral diseases, and it will also lead to reduced vegetable yields and greatly reduced quality due to large outbreaks of aphids and other pests.
5. Avoid excessive water control and leaf thinning
High summer temperatures cause large evaporation inside the greenhouse, resulting in increased water content in crops, but too much watering will affect crop growth. It is recommended to use the method of frequent light watering to ensure normal vegetable growth. The watering time and frequency can be determined according to the dry and wet conditions of the soil in the greenhouse and the weather conditions.
Summer is a period of vigorous vegetable growth. Many vegetable farmers thin leaves to ensure the nutritional needs of crops, but note that leaf thinning must be moderate. Follow the principle that leaves above the fruit should be “many but not crowded” and leaves below the fruit should be “few but strong”, so as to avoid sunscald caused by strong light directly hitting the fruit due to excessive leaf removal, which reduces fruit quality.
As long as the above techniques are followed when growing greenhouse vegetables in summer, it is still easy to obtain high yields.