The TLF lights introduced by Signify in recent past are nearly the same in size as the popular Toplighting Compact (TLC) lights that have found widespread application in high-tech greenhouse horticulture in recent years. However, the TLF lights offer a higher output (2,800 to 3,600 µmol/s) and ditto efficiency (up to 3.7 µmol/J), coupled with the proven reliability of Philips light technology. Compared to the TLC, growers can achieve a higher light level for the same wattage, or they can choose to install fewer lights for a similar light level. Next to the standard beam for modern, high greenhouses for optimal efficiency (µmol/J), Signify also supplies a wide beam, for optimal uniformity even in relatively low greenhouses and shorter distances between lights and crop.
Commenting on their decision, Jeffrey van Uffelen, on behalf of U-Grand – a joint venture of Van Uffelen Flowers and Michel Grootscholten’s MG Grand Nursery, said, “We did not have any experience with LED ourselves, but what I have seen and heard from others, the TLF gives us a lot of confidence. This also applies to Signify. They carried out many trials in chrysanthemum cultivation in recent years and also have a lot of practical experience growing chrysanthemums on a large scale under LEDs. We get along well and share the same vision. This project allows us both to grow and learn from each other. We are also taking a step forward in terms of cultivation technology, especially in lighting.”
LED installation partner Stolze will install as many LED as HPS lights in U-Grand’s new greenhouse in September. The LEDs deliver 128 µmol/m2/s, the HPS lights 70. Van said, “200 µmol with LED and HPS is no longer an exception in chrysanthemum cultivation. This allows you to achieve a higher plant density while fully maintaining quality. As a result of the light distribution and the high output of the TLF – 3,600 µmol/s – we need relatively few lights, while the light level is still very homogeneous. That is a hard requirement in chrysanthemum cultivation.”
The Van Tuijl brothers of Linflowers chose slightly different specifications. For their new greenhouse at the Darolin I site, they opted for TLF lights with an output of 2,750 µmol/s, offering a maximum efficiency of 3.4 µmol/J. They chose a spectrum that includes far-red light next to red and blue.
Explaining their intention, David van Tuijl, said, “In trials we found that with some additional far-red light you need fewer micromoles to grow branches with the desired length and weight. This allows us to efficiently increase plant density. We also feel that the chosen spectrum gives a wider cultivation range. By that I mean that almost all varieties respond very well to it. Without that little bit of far-red light, this module has a higher output (2,850 µmol/s) and is more efficient (3.7 µmol/J) but you may run into limitations sooner.”
Economy and restriction
A precondition for Linflowers’ lighting plan was the desire to stay within the available wattage based on the CHP and purchasing. The most efficient TLF with 2,850 µmol/s output came out slightly more favourably in that regard. This hybrid system also delivers 200 µmol/m2/s, divided into 120 for the TLF LEDs and 80 for the HPS lights. Stolze from Maasdijk will be responsible for the installation.