White LEDs: A Cost-Effective Alternative to Red + Far-Red LEDs
Many important greenhouse floriculture crops are long-day plants, meaning they require long days and short nights (usually less than 8–10 hours of darkness) to produce flowers early. In areas where winters have short days and long nights, the flowering of long-day plants grown during that time is delayed or inhibited. To shorten long nights and promote flowering of long-day plants, growers can use dim photoperiodic lighting at the end of the day (day-extension lighting) or in the middle of the night (night-break or night-interruption lighting). 16-hour days created from day-extension lighting or 4 hours of night-break lighting are generally sufficient to achieve complete flowering of long-day plants.In the past decade, “flowering” LED lamps with custom light spectra including red (R)…