Effect of light wavelength on growth and flowering of narcissi forced under short-day and low quantum irradiance conditions

Summary

Four narcissus cultivars were forced under artificial light using fluorescent lamps which emitted white (307 – 770 nm), blue (393 – 580 nm), red (540 – 760 nm), yellow (450 – 750 nm), or green (387 – 680 nm) light. The photosynthetic photon flux density was 12.5 μmol m^–2 s^–1, with a 6 h photoperiod. Light colour (wavelength) had no significant effect on flowering date, or on the number of flowers collected (P < 0.05). Narcissus bulbs exposed to blue light (393 – 580 nm) formed shorter, more rigid shoots of lower weight with 13 – 40% shorter leaves.