Plant growth and development depend on light, one of the most important environmental factors. Light affects plant morphology, physiology and metabolism. The spectrum of light, or wavelength distribution, is one property of light that can change the way plants respond. Different wavelengths have different effects on plant photosynthesis, flowering, stress tolerance and secondary metabolites.
The purpose of this article is to investigate the impact of LED lighting on plant growth and development.
The article presents the use of different coloured LED lights in barley, kale and flower cultivation and analyses their effects on the chemical composition and appearance of the plants. The article also discusses the potential and challenges of LED lights in plant breeding.
LED lights and their advantages
LED lights differ from other light sources in many ways. For example, fluorescent tubes produce light through a gas discharge phenomenon, in which an electric current ignites atoms in a gas and causes them to emit light. Sunlight, on the other hand, is natural light that is produced by a nuclear fusion reaction in the Sun’s core and emitted into space.
LED lights have many advantages for growing plants. LED lights are energy-efficient because they convert most of the electrical energy into light and produce little heat. LED lights are also long-lasting, with a lifetime of up to 50 000 hours or more. LED lights are also adjustable and versatile, as their colour, brightness and timing can be changed as required. LED lights can provide plants with an optimal light spectrum at different stages of growth and promote their health and productivity.
Effect of LED lights on plant development and light characteristics
Let’s start by discussing how LED lights affect plant development in general. Lots of variables.
CRI, or light quality
LED lights should have a high colour rendering index (CRI) to reproduce well the blue and red wavelengths that are important for plant photosynthesis.
CCT, or colour temperature control
LED lights should have adjustable colour temperature (CCT) to adapt to different growth stages. Adjustment range Warm 2500K – Cold 6500K.
Spectrum of light
The spectrum of light refers to the relative proportion of different wavelengths of light. Plants use blue and red light in particular for photosynthesis, where they convert light energy into sugar and oxygen. Blue light also promotes leaf growth and flowering, while red light stimulates stem elongation and flower formation. LED lights can produce different spectra with varying proportions of blue and red light. This allows optimum conditions for plant growth and flowering.
Light Intensity
Light intensity refers to the intensity or amount of light. Plants need enough light to communicate effectively and grow well. Light intensity also affects the surface area of plant leaves, stem thickness and sugar content. Too little or too much light can damage plant health and cause stress. LED lights can be used to adjust the light intensity to the right level for different plant species and varieties.
Duration of light
Light duration refers to how long plants receive light per day. The duration of light affects the diurnal and annual cycle of plants, or photoperiodism. Plants can be divided into long-day, short-day and neutral-day plants according to how long the day needs to be to trigger flowering. The duration of light also affects the endocrine and stress response of plants. LED lights can be used to lengthen or shorten the day as needed.
Benefits and drawbacks of Led lights for plant health
LED lights can have both benefits and drawbacks for plant health and adaptation.
Benefits include better photosynthetic efficiency, higher yields, better quality, faster growth, fewer pests and diseases, and the ability to grow under different conditions.
Disadvantages include costs, technical problems, environmental impacts and possible negative effects on plant morphology, metabolism and genetic diversity.
The use of different coloured LED lights in barley breeding and its effects on barley growth and yield quality.
The use of different coloured LED lights in barley processing is an interesting research topic related to the optimisation of lighting conditions for plants. LED lights allow the adjustment of different light spectrums and light cycles, which can affect the growth, development and quality of the barley crop.
Current situation with high pressure sodium lamps
The aim of barley breeding is to produce varieties that are suitable for different growing conditions and market requirements. Barley breeding programmes include several objectives, such as high yield, good quality, disease resistance, drought tolerance and short growing season. Barley breeding is mainly done in greenhouses, where environmental factors can be controlled and generation changes can be accelerated. High pressure sodium lights are commonly used in greenhouses as supplementary lighting, but they also have drawbacks such as high energy consumption, heat gain and poor controllability.
Led lighting improves the final result
LED lights are a new alternative for greenhouse lighting, offering many advantages over high pressure sodium lights. LED lights consume less energy, produce less heat and last longer. In addition, LED lights allow the adjustment of different light spectra and light cycles, which can affect the physiology and morphology of plants.
The spectrum of light refers to the relative proportions of different wavelengths of light, or colours. Light cycle means the alternation of light and dark during the day.
The colour of light matters
The use of different coloured LED lights in barley breeding can affect the growth and development of the plant in many ways. For example:
- red light promotes coupling and stem length growth
- blue light curbs stem length growth and increases leaf area
- green light penetrates the leaf layers better
The use of different coloured LED lights can also have an impact on e.g. barley yield quality, such as hectolitre weight, thousand grain weight and starch content.
Previous studies have shown that the use of different coloured LED lights in barley breeding can produce different results depending on the light spectrum, light cycle, variety and growing conditions.
For example, a study on the effects of different shades of LED grow lights on plant growth and development. The study found that in general, LED supplemental lighting accelerated plant growth.
Effect of LED light spectrum on the chemical composition and VOC (volatile organic compound) emissions of kale.
Collard greens are a healthy and nutritious vegetable that can be grown in a variety of light conditions. The light spectrum affects the growth, appearance and chemical composition of kale, which contains various secondary metabolites such as glucosinolates, phenolic compounds and VOCs. These compounds are important in the defence mechanisms, stress tolerance and nutritional value of kale.
Researched data
A Finnish study investigated the effect of LED light spectrum on the chemical composition and VOC emissions of kale. Leaf beetles were exposed to three different LED light spectra with varying proportions of blue and red light. In addition, the chemical composition of the leaves before and after mechanical damage, simulated by chopping the leaves into lettuce, was investigated.
How does the spectrum of LED lights affect the leaf litter?
The results showed that the spectrum of LED lights had an effect on the chemical composition and VOC emissions of the leaf litter. The red spectrum increased glucosinolate levels after damage, while the blue spectrum decreased them.
The highest concentrations of phenolic compounds were found in the equilibrium spectrum, where the blue and red light fractions were equal. VOC emissions were lowest in the red spectrum and highest in the blue spectrum.
The light spectrum also had an effect on the appearance and morphology of the leaves. The reddish spectrum caused the most visible damage to the leaves, such as necrosis and chlorosis. The balanced spectrum was the best for the appearance of the leaves, as it caused the least damage. Leaf size and wrinkling also varied across spectra.
The study showed that the spectrum of LED lights has a significant effect on the chemical composition and VOC emissions of kale, as well as its appearance and morphology.
LED lights offer the possibility to grow kale very efficiently and safely.
The use of LED lights in flower growing and its effects on the appearance and durability of flowers
The use of LED lights in flower growing and its effects on the appearance and durability of flowers
LED lights are increasingly popular light sources for growing flowers, as they offer a number of advantages over traditional light sources such as fluorescent or incandescent bulbs. LED lights consume less energy, produce less heat, last longer and allow the spectrum of light to be adjusted according to the needs of the plants.
The light spectrum is an important factor for plant growth, flowering and quality, as it affects plant photosynthesis, hormone balance, morphology and stress tolerance. LED lights can be used to create different lighting environments that stimulate or inhibit specific physiological processes in plants.
Studies have shown that the use of LED lights has a significant impact on the appearance and durability of flowers.
Blue and red led light for flowers
For example, the combination of red and blue light promotes flower growth, biomass production and pigment formation, making flowers more colourful and attractive.
Blue light for flowers
Blue light also increases the amount of leaf green in flowers, which improves their photosynthesis and stress tolerance.
Red light for flowers
Red light, on the other hand, stimulates earlier and more abundant flowering and prolongs the shelf life of flowers as cut flowers.
Using LED lights in flower growing is therefore an efficient and environmentally friendly way to improve the quality and beauty of flowers, as well as saving energy and costs. LED lights also make it possible to grow flowers indoors or out of season, so we can enjoy beautiful flowers all year round.
Frequently asked questions
How does the use of LED lights affect the quality of plants, such as taste, smell or nutritional value?
The taste and smell of plants are affected by VOCs (volatile organic compounds), which are volatile organic compounds produced by plants. The emission rate of VOCs depends on the spectrum and intensity of the light.
How does the use of LED lights affect plant yields, such as yield, flowering or seed production?
The use of LED lights can also have an impact on grain quality. LED lights can change starch and protein content, dough strength and elongation, and the gluten/gliadin ratio. However, the effects of LED lights vary between species and developmental stages, and their molecular mechanism is not fully understood. Therefore, the application of LED lights in greenhouses or nurseries should take into account the plant species, growing conditions and product quality factors.
How does the use of LED lights affect plant health, such as resistance, stress tolerance or pest control?
The use of LED lights can affect plant health in many ways. LED lights produce different wavelengths of light that promote photosynthesis, growth and flowering in plants. LED lights can also mimic natural light and circadian rhythms, improving plant quality and resistance.
How does the use of LED lights affect the environment, such as energy consumption, carbon footprint or waste management?
The use of LED lights affects the environment in many ways. LED lights are energy-efficient because they consume less electricity than traditional halogen or xenon lights. This reduces their carbon footprint and electricity bills. LED lights also have a long lifetime, up to tens of thousands of hours, reducing the need for waste disposal.
Summary and conclusions
We have found that LED lights are useful for growing plants because they produce little heat, consume little energy and can provide an optimal light spectrum for different plant species.
There are also some challenges in using LED lights for growing plants. For example, LED lights can be more expensive than traditional light sources such as fluorescent tubes or energy-saving light bulbs. In addition, LED lights may require special installation and adjustment to ensure that they illuminate the growing space evenly and effectively. Finally, LED lights can be unpleasant to the eyes or to the interior if they only have blue and red wavelengths.
Led lighting expert
LedStore has been an expert in led lighting since 2010. We have our own product design, so our products are technologically state-of-the-art.
We focus on light colour temperature controlled and high colour rendering index lights. We do around 500 lighting designs in a year.
We offer a service of custom made led strips, i.e. custom made led light strips in profile. Also installed.
Remember that we are always ready to offer our help to you along the way, by email (myynti@ledstore.fi) and by phone (045 251 4510). As always, feel free to share photos of your own projects on social media at ledstore.fi at Instagram and ledstore.fi at Meta. We love to see the cool things done by our LEDs, and it also helps to provide inspiration for those who are not sure about the power and awesomeness of LEDs. Did you know that we already have over 3500 pictures of our LED installations in our Gallery!
Gallery of Led lights:
Product gallery: Pictures of products in different installation locations
Indirect light: Indirect light in different spaces
Room-specific: Light in different rooms
References: Complete houses that have been photographed
