http://www.ledsmagazine.com/articles/2016/01/transcend-launches-broad-spectrum-led-based-t5-tube-for-horticulture-applications.html
Transcend takes the input of academia and its customers in crafting products with SPDs for specific applications. “Many companies build horticultural lights with just the blue/far red spectrum because of the hypothesis that these are the only wavelengths used for photosynthesis,” said DeMilo.
“Although this hypothesis had some great logic, that chlorophyll A and B absorb these wavelengths more strongly, it turns out that plant growth is far more complicated than this. Some of our customers have grown fantastic plants using 100% green light during testing. This makes sense as plants evolved for billions of years under sunlight. Many recent studies have shown that full-spectrum lighting with properly balanced ratios of wavelengths, say red to far red or red to blue, supports the most efficient plant growth.”
You might not think that white light is important in the application. But as our horticulture feature discussed, growers still need white lighting to work with the plants. Ironically, one of the 30W T5 LED tubes that Transcend offers as a replacement for 64W fluorescent lamps happens to have a CRI of 94 due to the broad SPD and significant energy in the red region.
Today, Transcend is offering the LED tubes in two SPDs. One is a broad-SPD called Seed-to-Harvest Photosynthetic White, and the other is a red-centric Fruit-and-Flower Wide-Band Deep Red. The tubes sell for $70. But Transcend plans other formulations. For example, the company has even developed an SPD for salt- and fresh-water coral growth working with a European partner.