The role of LED lights in the horticulture industry


With their capability to precisely control spectral composition, ensure low heat emission and deliver effective light output for years on end, without the need for frequent replacements, LED lights are set to transform the horticulture industry.

By Potshangbam July

The dependence on horticulture lighting is increasing every year with the burgeoning population and the scarcity of agricultural land. Thanks to LED technologies, indoor and vertical horticulture are both possible now, even without natural sunlight. As a result, the demand for LEDs has shot up, considering their unique advantages in comparison with existing horticultural lighting.

While energy efficiency has been the major reason behind the increasing adoption of LED technologies, there are other benefits that give it an extra edge over traditional lighting options. In horticultural farming, light plays an important role in promoting the growth of the plant, regulating about 90 per cent of a plant’s genes. LEDs have the capability to control the light’s spectral composition precisely, which can influence plant growth and morphology.

How LED lighting is ideal for horticulture
LED based horticultural lighting comprises the light-emitting diodes, usually available in a casing with a heat-sink and built-in fans. In such lighting systems, a ballast is not required separately, and can be inserted directly into a standard electrical socket. Functionally, when there is no sun, these lights are used as a source of daylight, which leads to the normal growth of the plants. They not only enhance the taste and quality of the fruits or plants, but also make it possible to produce higher yields in a shorter time. LED lighting has a wide light spectral output that delivers the varied spectral requirements of different plants. This lighting provides the intensity and colour spectrum as per the needs of different plants, which fuels plant growth.

In the case of traditional high-intensity discharge (HID) lighting sources, the spectral distribution is scattered, and it is difficult to alter the spectral light quality. Traditional HID lighting involves the use of lamps, which emit a high percentage of energy as infrared (IR) light. IR light is not photosynthetically active and significantly increases plant temperatures, which can harm the crop.

LED lights, on the other hand, are in harmony with the photosynthesis process, and provide the light composition that the plants require. Red light is the primary need for plants to undergo the photosynthetic process and can result in good germination. The blue light plays an essential role in determining the size of the plant, the red pigmentation and to some extent, the aroma and taste of the vegetables.

Technology advances
The advances in digital control technology with regard to LED horticultural lights have changed the cultivation pattern, resulting in better yields. One of the biggest advantages of LEDs is that they can be easily integrated into digitally controlled and programmable systems. They enable users to constantly monitor the light levels in the greenhouse. Besides, the systems allow users to set up programmes and run them automatically—the lights can be brightened or dimmed gradually as per the weather conditions.

These control systems are now available in an advanced format that offers more flexibility. They fit in smoothly with conventional climate control and greenhouse management systems. LED fixtures are very handy, and can be easily integrated with environmental sensing technologies. Instead of using the standard overhead strings of lights, LED fixtures can be placed near the plants without releasing excess heat that can affect the growth of the vegetables. LED fixtures are equipped with a heat dissipation system that uses anodised aluminum extrusion as a heat-sink. As per reports, horticultural LED fixtures have reached efficacies of up to 3.2µmol/J in 2019.

The possibility of colour spectrum manipulation using LED controls helps in crop morphology and development. The production of high-value nutritional compounds like pigments and secondary metabolites can be achieved. Besides, cloud based software has been developed that can be connected to the lighting hardware. This software gives users control over the kind of light that the plant is exposed to. As it turns out, vegetables grown using such technologies have softer leaf tissue than the vegetables cultivated in the field.

Advantages of LEDs for horticultural lighting

  • LEDs last longer and consume less electricity than high pressure sodium (HPS) lamps.
  • They emit low temperatures and hence can be placed in close proximity to the plants without causing any damage.
  • They have a long operational life of 30,000 to 50,000 hours.
  • LED lights do not have heavy metals or glass, unlike sodium based lights. The plants are safe, because no toxic contaminants are released into the air even if the LED fixtures break.
  • The quality of the crops can be ensured constantly, regardless of the unfavourable weather conditions outside the enclosed greenhouses.
  • They can be used to improve the nutritional value, taste and aroma of the plants.
  • LED lights do not take time to reach their full capacity. They can be switched on and off in seconds, unlike HPS lamps, which take at least 30 minutes to warm up or cool down.
  • They make it possible to take up vertical or indoor farming, which solves the problem of land/space unavailability.
  • Horticulturists can reduce their operating costs by using more energy-efficient LEDs, which can help to boost their profit margins.
  • LEDs enhance the amount of vitamin C in the plants.

In fact, these advanced LED technologies that offer a broad colour spectrum and a range of outputs stimulate the growth of the plants in a healthy manner. They have controlled the use of fertilisers and chemicals significantly, thus saving costs too.

The way forward
Globally, the horticulture lighting market is set to reach US$ 6.41 billion by the end of 2023, as per a Market Research Future (MRFR) report. The market is expected to grow at a stunning rate of 20.44 per cent during the forecast period. This is because horticulturists are now incorporating LEDs in their farming practices in view of the benefits they offer. The good news is that the price of LED products has been dropping gradually which has increased their acceptance in horticultural farming. On the whole, LEDs have the potential to fundamentally change the prospects of horticulture.

Alexander Wilm, applications engineer and expert, horticulture lighting, OSRAM Opto Semiconductors,
shares his views on how LED lights are transforming the horticultural lighting market.

The role of LEDs in horticultural farming
Artificial light has been successfully used in greenhouse lighting for many years. The use of LEDs now creates a variety of other possibilities for improving and optimising plant cultivation.

The advantages offered by LEDs
While high-pressure sodium vapour lamps were used back in the day, LED lighting is the technology of choice for state-of-art horticultural lighting. One of the advantages is that LED based systems can save up to 40 per cent of energy compared to high-pressure sodium vapour lamps. Further, smart LED lights with variable wavelengths can be used to control the exact day and time of every harvest. Different combinations of wavelengths can even determine the taste and appearance of crops as well as increase vitamin and nutrient content. Another benefit of LED based horticulture lighting is speed. The entire growing cycle from the time the seeds are planted, to harvesting the crop, is shorter.

Technological trends and advances
In addition to energy efficiency, the flexibility of LED technology, thanks to its digital controllability, is a major advantage over traditional lighting technologies.

Purchasing tips
In horticulture lighting, light is a production tool. To ensure you choose the right horticultural lighting, you should definitely focus on quality. Even a small degradation of the light output has a direct impact on the crop yield and can be quantified. The higher the quality of the technology used, the better and wider its uses are.

Transformation in the horticulture sector
The methods of growing vegetables and herbs is also evolving with new digital LED lighting technologies that help farmers optimise crop yields and even enable farms to sprout in the middle of cities and urban centres. With a rising population and rapid urbanisation, fresh food is in high demand, especially in densely populated cities around the world. In response, vertical farms are springing up in many metros, growing produce in warehouse-like facilities powered by smart lighting, sensor systems and artificial intelligence.


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