Choosing the right LEDs to regulate flowering in greenhouses

Numerous light-emitting diode (LED) lamps have been developed for horticulture applications during the past several years. However, not all LEDs are created equal; for example, some are better than others at regulating flowering. Research performed at Michigan State University has shown that the light spectrum is key to regulating flowering. A spectrum rich in red light (600 to 700 nm) is capable of inhibiting flowering of short-day plants. The inclusion of far red (700 to 800 nm) with red light can sometimes accelerate flowering of long-day plants. At the low light intensity typically delivered (≈2 µmol·m−2·s−1), blue and green light are less or not effective at regulating flowering.