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Traditional incandescent lamps are used by many growers to backlight seedlings, but they are of no use. The emitted yellow-orange glow does not help the plants to thrive. The entire useful spectrum is obtained from LEDs or phytolamps. The disadvantage is the high cost of lighting equipment. Fluorescent seedling lampsthat emit the entire required light spectrum.
Light source device
In everyday life, fluorescent lamps are known as fluorescent lamps. The name comes from a white glow. The device consists of a housing with a diffuser. The lamp is a glass tube, sealed at both ends and powered by a choke. The inner surface of the glass walls is coated with a white powder - a phosphor. A plinth is attached to both ends of the tube. Through its contacts, voltage is applied to the filament. The inner space under pressure is filled with argon and a small amount of mercury.
Fluorescent and traditional incandescent lamps have one similarity - tungsten filament. When voltage is applied, the coil emits heat, which contributes to the formation of UV radiation in argon and mercury vapor. For the human eye, the rays are not visible, but plants are beneficial. The phosphor deposition contains phosphoric substances that form the spectrum and enhance the glow. Thanks to additional components, the fluorescent tube glows 5 times more than a traditional incandescent lamp.
Seedling response to illumination
In natural conditions, plants develop under sunlight. Seedlings are grown on a windowsill or greenhouse. Daylight is not enough to penetrate the glass. It should be borne in mind that the cultivation of seedlings falls on a period of short daylight hours, and artificial illumination is indispensable.
Traditional incandescent bulbs emit a yellow-orange light that is useless for plants. The lack of UV rays inhibits the growth of seedlings and the process of photosynthesis. As a result, unsuccessful shoots are observed, withering shoots on long thin legs. In the fall, such planting material will produce a poor harvest, and during the growing season the crops will be sick.
When the seedlings are illuminated with fluorescent lamps, conditions are created that are as close to nature as possible. There are two important colors in UV rays: blue and red. The beneficial spectrum for the plant suppresses the harmful ranges of other colors and promotes the full development of plants.
Useful and useless spectra
The full spectrum of colors is present in the sun color, and it has the most positive effect on the life of plants. The fluorescent tubes are able to provide the seedlings with blue and red light. These colors are maximally absorbed by plants and are beneficial:
- The blue color contributes to the correct development of cells. The stem of the plant does not stretch, but thickens and grows stronger.
- The red color is useful for germinating seeds, and also accelerates the formation of inflorescences.
Red and blue colors are optimal for seedlings, but the percentage of benefits depends on absorption.There is such a thing as absent-mindedness. Foliage absorbs direct rays worse. When used with a matt reflector with a fluorescent lamp, the light becomes diffused. Rays of red and green color become more favorable for absorption by vegetation.
Varieties of light sources
Considering which fluorescent lamp is best for seedlings, it is worth considering that the light sources of this group are divided into two types.
Traditional daylight sources
The simplest cheap option is economy class fluorescent lamps for seedlings, used to illuminate premises. They emit daylight with limited amounts of blue and red. Products differ in shape. The traditional "housekeeper" in the form of a spiral or U-shaped tubes, twisted into a chandelier holder, is similar from this group. However, for growing planting material, this option is poorly suited due to the small area of \ u200b \ u200blighting.
The best option is a tube. Lamps are produced in different lengths, which allows them to be distributed over the entire rack. The disadvantage of the light source is its low power. We have to hang fluorescent lamps for tomato seedlings or other garden crops as close to the plants as possible. In terms of the area of illumination, the tube can replace 2-3 "housekeepers".
Phytoluminescent light sources
If you decide to seriously start growing seedlings, it is preferable to acquire phytoluminescent light sources. The lamps are specially designed to illuminate plants in greenhouses. A feature of the product is an unusual glow spectrum, which is as close as possible to the characteristics of the sun's rays. The composition is dominated by pink and lilac colors. For human vision, radiation creates discomfort, and benefits plants.
The advantage of phytolamps is low power consumption, long service life and safe use. Due to its small size, the phytoluminescent lamp can be placed in a confined space, and it illuminates a large area.
The main disadvantage is the spectrum, which is uncomfortable for vision. When growing seedlings inside a living room, you will have to take care of reflectors and protective partitions. The design should direct the glow to the planting material as much as possible, and not into the eyes of the residents of the house.
Among the popular manufacturers of phytoluminescent lamps, the brands Osram, Enrich and Paulmann stand out. Devices for illumination are available in different powers and almost all are equipped with reflectors.
Lighting organization
To correctly determine which fluorescent lamps are suitable for seedlings, you need to know what optimal lighting is acceptable for the crops being grown.
Brightness
Each culture is distinguished by its sensitivity to light. Some people like bright lighting, while others like soft light. It is not profitable to buy many lamps with different wattage to illuminate different seedlings. It is better to adjust the brightness by the height of the suspension of the lighting fixtures.
Cucumbers or cabbage love direct sunlight. Lighting devices are removed from the tops of the seedlings at a distance of 20 cm. Eggplants, tomatoes and peppers experience discomfort under bright lighting. Fluorescent lamps are removed from the tops of the seedlings at a distance of up to 50 cm.
The height of the luminaires is constantly monitored. Seedlings grow rapidly and their tops should not come close to the critical distance to the lamps.
Backlight duration
At different ages, the planting material requires a certain duration of illumination. In winter, in cloudy weather, the fluorescent lighting is switched on for 18 hours. On sunny days, the backlight is turned off. Plants need to get used to natural light. The duration of the artificial light is reduced to 12 hours.
The duration of the illumination depends on the age of the plants. After sowing the seeds above the boxes, the lights are turned on around the clock to speed up germination. Sprouted plants need rest at night. Constant lighting will not be good. A good result is obtained by using lamps with different characteristics. The combination of lighting devices allows you to get a spectrum as close as possible to the sun's rays.
The video tells about the effect of light on seedlings:
Self-made backlight
When making the backlight, it is advisable to choose the shelves of shelves and fluorescent tubes of the same length. The optimal size is 1 m. It is better to use factory-made lamps. The devices are compact, equipped with a switch, all electrical elements are hidden under the casing, and the glass tube is covered with a plastic frosted diffuser.
In a homemade backlight, they must hide the junction of the base with the cartridge with a casing. The wiring is laid along the racks of the rack. The choke is installed in the box farther from the lamps so that when watering the seedlings, the water does not cause a short circuit.
The lighting is mounted on the underside of the shelf of the upper tier of the rack. The glass surface of the tube should not come into contact with any objects. On wide shelves, it is optimal to install 2 lamps at the edges. If the brightness of the backlight is dimmable, the devices can be fixed to the shelves with rigid steel straps. Otherwise, the lamps are suspended from ropes to adjust the height.
When organizing the illumination of seedlings, one must remember about electrical safety. Water that gets on the lighting device during irrigation will create a short circuit. There is even a threat of destruction of the glass tube, where mercury, which is dangerous to humans, is inside.
