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Traditional incandescent lamps are used by many vegetable growers for illumination of seedlings, but there is no benefit from them. The yellow-orange glow emitted does not help plants develop. The entire useful spectrum is obtained from LEDs or phytolamps. The disadvantage is the high cost of lighting equipment. Fluorescent lamps can become a full replacement lamps for seedlingsemitting the entire necessary light spectrum.
Light source device
In everyday life, fluorescent lamps are known as fluorescent lamps. The name comes from the 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 covered with a white coating - phosphor. A base is attached to both ends of the tube. Through its contacts, voltage is supplied to the filament. The internal space under pressure is filled with argon and a small amount of mercury.
Fluorescent and traditional incandescent lamps have one thing in common - a tungsten filament. When voltage is applied, the coil emits heat, which promotes the formation of UV radiation in argon and mercury vapor. The rays are not visible to the human eye, but they benefit plants. The phosphor coating contains phosphorus substances that form the spectrum and enhance the glow. Thanks to additional components, the fluorescent tube glows 5 times stronger than a traditional incandescent lamp.
Reaction of seedlings to lighting
Under natural conditions, plants develop under sunlight. Seedlings are grown on a windowsill or greenhouse. There is not enough daylight coming through the glass. It should be taken into account that growing seedlings occurs during a period of short daylight hours, and it is impossible to do without artificial lighting.
Traditional incandescent bulbs emit yellow-orange light that is useless to plants. The absence of UV rays inhibits the growth of seedlings and the process of photosynthesis. As a result, unfriendly shoots and withering sprouts on long thin legs are observed. In the fall, such planting material will produce a poor harvest, and the crops will become sick throughout the growing season.
When 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 spectrum that is beneficial 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 sunny color, and it has the most positive effect on the life of plants. Fluorescent tubes are capable of providing seedlings with blue and red light.These colors are maximally absorbed by plants and provide benefits:
- Blue color promotes proper cell development. The stem of the plant does not elongate, but thickens and becomes stronger.
- The red color is beneficial for germinating seeds and also accelerates the formation of inflorescences.
Red and blue colors are optimal for seedlings, but the percentage of benefit depends on absorption. There is such a thing as absent-mindedness. Direct rays are absorbed worse by foliage. If you use a frosted reflector with a fluorescent lamp, the light becomes diffused. Red and green rays become more favorable for absorption by vegetation.
Types of light sources
When considering which fluorescent lamp is best for seedlings, it is worth considering that light sources in this group are divided into two types.
Traditional daylight sources
The simplest and cheapest option is economy class fluorescent lamps for seedlings, used for indoor lighting. They emit daylight with a limited amount of blue and red light. Products differ in shape. The traditional “housekeeper” in the form of a spiral or U-shaped tube, screwed into a chandelier socket, is similarly from this group. However, this option is not suitable for growing planting material due to the small lighting area.
The best option is a tube. The 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. You have to hang fluorescent lamps for tomato seedlings or other garden crops as close to the plants as possible.In terms of lighting area, 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 designed specifically for illuminating plants in greenhouses. A special feature of the product is its unusual luminescence spectrum, which is as close in characteristics as possible to the sun's rays. The composition is dominated by pink and lilac colors. For human vision, radiation creates discomfort, but benefits plants.
The advantage of phytolamps is low energy consumption, long service life and safe use. Due to its small size, a phytoluminescent lamp can be placed in a limited space, but it illuminates a large area.
The main disadvantage is that the spectrum 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 as much as possible onto the planting material, and not into the eyes of the residents of the house.
Among the popular manufacturers of phytoluminescent lamps are the brands “Osram”, “Enrich” and “Paulmann”. Illumination devices are available in different capacities and almost all are equipped with reflectors.
Organization of lighting
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 crop differs in sensitivity to light. Some people like bright lighting, while others like soft light. It is not profitable to buy many lamps of different power to illuminate different seedlings. It is better to regulate the brightness by the height of the lighting fixtures.
Cucumbers or cabbage love direct sunlight. Lighting devices are distanced 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 lamps is constantly monitored. Seedlings grow quickly and their tops should not come within a critical distance of the lamps.
Backlight duration
At different ages, planting material requires a certain duration of illumination. In winter, in cloudy weather, fluorescent lighting is turned on for 18 hours. On sunny days the backlight is turned off. Plants must get used to natural light. The duration of artificial illumination is reduced to 12 hours.
The duration of illumination depends on the age of the plants. After sowing the seeds, the lights above the boxes are turned on around the clock to speed up germination. Sprouted plants need rest at night. Constant lighting will not be beneficial. Good results are achieved by using lamps with different characteristics. Combining lighting devices allows you to obtain a spectrum that is as close as possible to the sun's rays.
The video talks about the effect of light on seedlings:
Making your own lighting
When making lighting, it is advisable to select rack 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 a casing, and the glass tube is covered with a plastic matte diffuser.
In homemade lighting, be sure to hide the junction of the base and the socket with a casing. The wiring is laid along the rungs of the rack. The choke is installed in the box further from the lamps so that when watering the seedlings, the water does not cause a short circuit.
Attach the lighting to the underside of the shelf in 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 adjusted with a dimmer, the devices can be secured to the shelves with rigid steel tapes. Otherwise, the lamps are hung on ropes to adjust the height.
When organizing illumination of seedlings, you need to remember about electrical safety. Water that gets onto the lighting fixture during irrigation will create a short circuit. There is even a threat of destruction of the glass tube, which contains mercury that is dangerous to humans.
