Sep 28, 2021

The best practices in horticultural lighting is rooted in growers’ experience

Category: Illumination
It was through the effort of growers and horticultural research institutes that the industry determined that broad-spectrum white light rather than a combination of royal blue and deep red produced equal or better results.
It was through the effort of growers and horticultural research institutes that the industry determined that broad-spectrum white light rather than a combination of royal blue and deep red produced equal or better results.

When it comes to growing plants, there is no better way to learn than by getting your hands dirty.

The practice of horticulture is affected by a huge array of variables, from the choice of growing medium, temperature, rates of irrigation, and the application of fertilizer, to exposure to pests and diseases. Changes in one variable, such as the moisture in the soil and atmosphere, affect multiple others, such as growth rates and susceptibility to fungal disease.

Successful growers learn to manage and balance the complex interactions between these variables by experience and through practical experimentation. This applies as much to indoor growers working under artificial lighting as to outdoor horticulture. Indoors, growers have developed a practical understanding of the right control and management of lighting, down to the spectrum of the light, for each type of crop they grow, and the conditions in which they grow them. Growers and agricultural scientists that study crops and lighting continue to define and refine the understanding of what makes the best horticulture light.

So while our engineers are experts in the development and production of advanced horticultural LED products, our technical knowledge does not extend to the field of agricultural science. So, one might ask, how is Lumileds ensuring that its horticultural LED products meet the future needs of growers?

Body of established horticultural best practices

For the most commonly grown indoor horticultural crops, such as leafy greens, tomatoes, and medicinal cannabis, the industry has a well-developed set of standard lighting practices which are known to produce high yields and good plant health. For cannabis, for instance, a combination of broad-spectrum white plus deep red LEDs is widely deployed.

It was through the effort of growers and horticultural research institutes that the industry determined that broad-spectrum white light rather than a combination of royal blue and deep red produced equal or better results. Growers found that fixtures in which white LEDs replaced the royal blue emitters came at a lower purchase cost and produced healthier crops with equivalent or better yields. And they offered an added bonus: the white light is a far better illuminator, enabling growers to see their plants better, making it easier to care for them and harvest the crops.

The role of the LED supplier

There is room for some humility on the part of the LED supplier, then. Here at Lumileds, we bow to the superior expertise of our customers in the horticultural lighting field, and of the growers themselves.

So how can we best contribute to the continuing improvement in horticultural lighting practices? There are three important roles that Lumileds plays:

Higher PPF, Longer Life, Ruggedized, Lower Cost

We control the entire construction of our LEDs – from epitaxy to materials to packaging – and we’re committed to continuous improvement. High temperatures and high humidity are common in horticulture, so we make specific design choices and validate those choices with rigorous testing to ensure that our LEDs will last in harsh environments. So our horticulture LED packages are designed for high tolerance to moisture and sulphur. Our horticulture LEDs are also specially tested, binned, and documented for horticultural users. The LEDs are binned by photosynthetic photon flux (PPF) – the parameter of concern to growers – rather than luminous flux. The products’ datasheets provide comprehensive PPF and spectral data to enable horticultural customers to make informed and intelligent buying decisions.

Contribute to horticulture knowledge

We sponsor targeted scientific research to complement the development efforts of fixture manufacturers and growers. Most recently, Lumileds’ Dr. Wouter Soer co-authored a research paper sponsored by NASA which described a finding about the most efficient combination of LEDs for growing vegetables in space.

We support growers and lighting equipment manufacturers

We support growers’ and lighting equipment manufacturers’ experimentation by providing the industry’s broadest portfolio of horticultural-grade LEDs. Different plants under cultivation might benefit from small but important differences in spectral profile. In the Lumileds SunPlus lines and the LUXEON 3030 HE Plus Horticulture and LUXEON 5050 Horticulture LEDs, customers can select products across a broad color and performance range designed to give growers and luminaire manufacturers the ability to choose the light that works best for their applications and the confidence that every LUXEON will deliver superior performance and ruggedness.

Technology development to improve PPF and PPE

The optoelectronics technology expertise of Lumileds continues to be put to work in pursuit of ever better horticultural LEDs. Improvements in semiconductor materials and production techniques, in phosphor coatings, and in other aspects of LED design will continue to produce improvements in PPF and PPE through the rest of this decade.

How to deploy these high-performance LEDs, and the best recipe for any given crop? On these questions, we open the floor to those who get their hands dirty.