Table 1.
Effects of 3 days of continuous darkness and 3 days of a 12 h dark/light cycle, on flower opening in cut Iris x hollandica cv. Blue Magic flowers, with a stem length of 45 cm and all leaves attached. At the onset of the experiment flowers either showed the tips of the tepals of the closed bud (mature buds) or were about to show the tips (immature buds). Flowers were in a climate-controlled room at 20 °C and 15 μmol m−2 s−1from Philips TDL 36 W/84 cool white fluorescent tubes, from 7 a.m. to 7 p.m., and either in a perspex chamber (RH about 99%) or outside the chamber (RH 60%). Two chambers were used, one in which the light of the climate-controlled room could enter from five sides, and one covered with black plastic (complete darkness). The degree of flower opening, expressed as the angle between tepal bases, and the length of pedicel + ovary were measured after 3 d of storage.