In the early spring, when greenhouses are used to grow vegetable seedlings, they are prone to frost damage in cold weather and measures should be actively taken to prevent freezing. Increased light intensity, strong photosynthesis of seedlings, production of sugar and starch and other nutrients, the ability to resist cold is strong. In order to make the seedlings shine more in the sunlight, we should try to expose the coverings such as the cover grass and weeds in the temperature range that can maintain normal growth as early as possible. Even if it is overcast on cloudy days and rainy days, it is better to use high light transmittance. Non-drip or dust-proof film, often keep the film surface clean. The humidity in the control humidity booth is too high, the water content in the seedlings is too high, and the concentration of the cell fluid is too low, which is prone to frost damage. Due to the lower temperature in early spring and the weaker light, the humidity in the shed is too high to induce the disease. In this regard, nursery greenhouses must strictly control the number of watering and watering, when the humidity is too high to enhance ventilation. Ventilation should be carried out at high temperatures around noon to prevent cold winds from blowing directly onto the seedlings to cause freezing damage. Scientific fertilization does not apply nitrogen fertilizer to avoid reducing the cold resistance of seedlings. Potassium fertilizer can increase the cold resistance of seedlings. The application of sweet and sour liquid to the seedlings can increase the sugar content and hardness of the leaf meat, and can also improve the cold resistance. Strengthen the coverage of the night outside the shed should cover quilts, straw and other insulation materials, and keep the cover is often in a dry state, the interior of the shed should be hung with two layers of film, buckle small arches and other multi-layer covering insulation. In the north of the greenhouse, straw can be used as a windbreak to block wind and cold. Temporary warming greenhouse temperatures below 15°C during the day and below 5°C at night may cause cold damage or freezing injury to the seedlings. In this regard, before the advent of the cold current, temporary heating devices such as heaters and stoves should be installed in the sheds to artificially supplement heat.
Laser Measurement Solutions
Chengdu JRT is a world leader in the design and manufacture of highly accurate, precise and digital and analogue laser measurement sensors, including serial laser distance transducer,usb laser distance module,distance module ttl laser sensor rs232/RS485/Bluetooth. These Laser Distance Sensor products are widely used in many smart industrial precise measurement soluitons: robot,crane,etc. This laser distance measure technology, combined with the high speed, 1mm high resolution and accurate measurement, specially the micro laser sensor(41*17*7mm),will confidently and accurately solve your precision measurement problem.
Laser Distance Measurement,Laser Measurement Sensors,Laser Distance Measurement,Smart Measure Sensor
Chengdu JRT Meter Technology Co., Ltd , https://www.jrt-measure.com