How to grow tomatoes under LED light
Currently, the most popular form of supplemental plant lighting in greenhouses is high-pressure sodium HPS lamps, which are effective in the cultivation of many species. However, these lamps show a higher energy consumption and a short service life.
Moreover, the spectrum of sodium lamps is not able to fully meet the needs of plants. Nowadays you can grow tomatoes under LED light. Lighting crops with LEDs is an attractive alternative to lighting with HPS lamps.
Research has shown that with the appropriate spectrum of light, obtained from LED sources, a 20% increase in the yield of tomatoes and an improvement in their quality. This is achieved with 50% energy savings compared to growing with traditional sodium lamps
Why is the light spectrum important?
In year-round cultivation, it becomes necessary to use appropriate lighting. It is one of the most important factors contributing to the proper growth and development of plants.
Light provides the plant with the necessary information about its surroundings. It drives photosynthesis, where it converts into chemical energy. An important parameter is not only the intensity, but also the spectral composition of the light.
Due to the different reactions of plants to individual colors and their proportions. It is important to match the spectrum to a specific crop and variety.
Therefore, when you decide to replace lighting in a greenhouse, make sure to choose right light spectrum.
Even slight changes in the light spectrum can cause significant differences in plant morphogenesis. Tests on vegetable seedling far red showed that an incorrect dose of this spectrum band resulted in a number of unfavorable changes, such as elongation of the hypocotyl and internodes.
The shape and size of the tomato fruit depend on the spectrum
Laboratory tests have shown that the shape, weight, color and other properties of the fruit depend on the type of light. These features can be designed by juxtaposing the appropriate wavelengths of light and their intensity. Also, the amount of flower buds and hence the yield may vary depending on the ratio of blue, red and white light.
The fruits obtained in the experiments were tested at the IHAR Institute for the content of vitamin C, lycopene and sugars. It turned out that a small amount of UV light supports the production of vitamin C. Unforunately too much of it causes too much stress on the plant and causes the opposite effects.
How much light does a tomato plant need indoors ?
Of all the spectra tested, the LED spectrum composed of white light at 4000 K with the addition of red light had the best effect on growth and fruiting. This spectrum also yielded better results than the sodium lamp.
In his case, not only the average quantity of tomatoes allowed for sale increased, but also their weight. The average fruit produced weighed 20% more than the tomato under the HPS lamp. That is despite the use of LED lamps with twice less power. The experiment compared 250 W HPS lamps with 125 W LED lamps.
Under the LED spectrum used, the plants also developed a much more extensive and stronger root system. Additionally, parameters such as the content of lycopene and other antioxidants as well as the content of sugar, which contribute to the health and taste of the fruit, also increased. So far, no side effects of irradiation that could endanger the cultivation have been observed.
