Greenhouse LED lighting plays a critical role in ensuring plant yield and health all year round. For most greenhouse growers, light is a commodity, an essential consideration and tool that they cannot take for granted as they plan their greenhouse design, crop and installation. Light is the catalyst and pivot upon which a successful greenhouse succeeds, or fails.
Depending on the climate that you’re planning on building your greenhouse in, you will need to take a variety of factors into account to ensure that your light is right all year round. In temperate climates sunlight is limited with shorter days and a low daily light integral (DLI) in certain seasons which means that you need to adapt your greenhouse lighting to ensure that plants are receiving the right light for rooting, growth and quality.
When planning your greenhouse lighting, there are several considerations you need to make, and questions you need to answer, to ensure that your design meets your grower’s expectations.
01: Understanding DLI in greenhouses
One of the most important parts of any greenhouse lighting design is understanding the value of DLI. Measured by the total volume of PAR photons that gather in one area over a period of time, DLI provides you with insight you need to determine which areas need work, what kind of light is needed, and how to optimise your lighting planning.
Because DLI is the amount of light that’s photosynthetically active, it has a direct impact on how well your plants grow, the quality of your crops, and your yield. It needs to sit on your greenhouse build list alongside soil, shade, nutrients and type of lighting. And it has to be managed carefully to ensure that your greenhouse lighting adapts to DLI across different seasons, day lengths, time of year, latitude and more. Every one of these factors has an influence on your DLI so you need to know how you can effectively improve it to get the results you want.
When it comes to greenhouse lighting, you need to use supplemental lights to tightly manage your DLI and ensure that light has right effect on your crops. There are several studies that unpack how supplemental lighting can be of immense value in greenhouse lighting, and how light limiting conditions can delay growth and development.
The upshot? Greenhouse lighting DLI needs to be carefully managed in light of, excuse the pun, how invaluable it is.
02: The value of greenhouse light
In addition to DLI considerations, you need to unpack temperature, visible wavelength and space. There has been an increased demand for spaces that can optimise plant growth throughout the year has led to a significant upsurge in greenhouse areas globally. According to a study released by Cuesta Roble, the published global greenhouse vegetable area in 1980 was 150,0000 hectares and now it’s 496, 800 hectares. This is largely due to demand, greenhouse capabilities, and so much more.
This is what makes it imperative that you light your greenhouse in ways that enhance plant growth and go beyond DLI. Another factor to consider is the ways in which lighting can leverage the different light spectrums, to influence the growth and health of plants. Grow lights and artificial lighting solutions play a powerful role in ensuring that plants are provided with the best possible environments in which to grow.
Studies have found that grow lights are instrumental in providing growers with richer control over greenhouse growth outputs and optimisation. LED grow lights have become very popular because they offer superb alignment with light spectrum requirements across multiple use cases and greenhouse environments. If installed properly – it’s always advisable to use a bespoke lighting service that can ensure all LED grow lights are correctly aligned, placed and prepared – LED grow lights can be used to provide the different wavelengths required at each stage of plant growth, seamlessly.
You would need to consider grow lights that can meet the following ranges:
- 700-800nm – this increases the rate of photosynthesis and can promote extension growth.
- 610-700nm – this is ideal for chlorophyll absorption, germination, flower and bud development.
- 510-610nm – this green light helps with photosynthesis and the size and weight of plants.
- 440-500nm – light that plays a significant role in plant quality, root development and chlorophyl absorption
- 315-400nm – the longest UV light wavelength that enhanced plant pigmentation, and thickens leaves
- 280-315nm – ultraviolet light that has a negative impact on plant growth
- 280nm – the visible wavelength that can be toxic to plants unless correctly placed in terms of light quantity and distance
Lighting has been used to grow plants for nearly 150 years so there has been plenty of time for the technology to evolve and the solutions to adapt to changing greenhouse lighting demands and conditions. LED lighting solutions have grown in popularity and scope over the past few years because they offer growers remarkable versatility and control in complex greenhouse environments.
03: Greenhouse lighting: A study in efficiency
A recent case study published in Agronomy and entitled ‘Supplementary LED Interlighting Improves Yield and Precocity of Greenhouse Tomatoes in the Mediterranean’, found that the use of LEDs in protected horticulture enabled enhanced plant growth. The study examined the impact of supplemental LED interlighting on the growth, development, yield and quality of high-wire tomato plants throughout the different seasons.
The objective was to establish if the value of LED lighting could be proven in the greenhouse context. The result was that there was accelerated ripening in spring by one week, and by two weeks in summer. The plants also produced 16% more fruit. The overall conclusion was that LED lighting within the greenhouse was potentially feasible and relevant for tomato greenhouse production in the Mediterranean region.
04: Greenhouse lighting: The LED effect
LED grow lights are designed to be as energy efficient as possible while still delivering the required light output at scale. If they are laid out efficiently, meeting very tightly managed design standards, they can maximise plant growth and health with minimal demands on power. And this is just one of the areas where LED lighting plays a positive role in the transformation of greenhouse plant output.
In addition to cutting costs without cutting out quality, LED lighting lasts for longer. The diodes have a longer lifespan than other lighting solutions which means the cost of replacement bulbs doesn’t hit the bottom line as often as with competitor solutions. This is a tidy cost saving that delivers long-term value to the bottom line.
However, LED lighting isn’t just measured by its cost-effectiveness and reduced power consumption. It also ticks quite a few important boxes for greenhouse growers. These include:
You can speed up the harvest cycle of your plants by moving them through their grow cycle faster. This was shown in the case study above is a proven way of achieving higher, faster yields, and can be applied across multiple greenhouse conditions and environments. LED grow lights effectively help you to add more grow cycles into each year.
Variable spectrum control gives you rich and granular control over your lighting within your greenhouse. It isn’t a function of every LED light – you do need to select the right LED grow lights for your objectives – but it is one that makes your life a lot easier if you want to really optimise your greenhouse environment.
Create your own day by using LED lights to change the sunrise/sunset timing within your greenhouse. This has the benefit of controlling different plant processes so you can get the plants to really flourish with longer daylight times and improved access to light.
Maintain trusted and absolute control over your light quality over the long term with trusted solutions that have long lifespans. You can adapt your greenhouse lighting setups to remain consistently on your game when it comes to plant health and you can enjoy longer light lifetimes with lighting solutions that are designed to go the long haul.
05: Greenhouse lighting: Why the LED is King
LED lighting systems are designed to meet the changing and demanding needs of growers who want to get more from their plants and greenhouse investments. With the science to back them up, and the right partner to make sure they are optimised correctly, LED grow lights can fundamentally change your plant growth, health and yield.
You just need to make sure that you collaborate with a company that has a full and deep understanding of LED lighting and how it can be used effectively. Every light placement, every light spectrum, every degree of heat emitted – these factors all have to be considered when implementing a truly relevant and capable greenhouse lighting solution.
Work with a trusted partner who can create the right recipe for your environment and who has the latest technology and science at their fingertips, ready to help you shift your yield forwards. Bespoke lighting may sound expensive, but it doesn’t have to be, and the right lighting could see you achieve returns on investment (ROI) that help you grown more for less.
We can help you transform your greenhouse lighting with the right technology, expertise and science. Contact us on 01332 410601 to speak to one of the team.
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