Flower opening in Iris (Iris x hollandica) depends on elongation of the pedicel + ovary. This elongation lifts the bud above the point where the sheath leaves no longer mechanically inhibit lateral tepal movement. We here report on the effects on flower opening of storage at various temperatures, of holding the flowers dry rather than in water, and of a 12 h light/dark cycle instead of darkness, in cv. Blue Magic. During 3 d of storage in darkness at 11 degrees C or 6 degrees C the flowers placed in water opened. Flowers stored at 3.0 degrees C did not open during the storage period but did so during subsequent vase life at 20 degrees C. Flowers stored in water at 0.5 degrees C remained closed, even during subsequent vase life at 20 degrees C. None of the flowers that were stored dry for 3 d at 15 degrees C, 11 degrees C, 6 degrees C, 3 degrees C or 0.5 degrees C opened during vase life. Compared to flowers placed in continuous darkness, a rhythm of 12 h light and 12 h darkness inhibited opening during a 3 d storage period at 20 degrees C. It is concluded that cut Iris flowers (a) can be stored in water at 3 degrees C for more than a week, but cannot be stored for 3 d or more in water at 15 degrees C, 11 degrees C, 6 degrees C or 0.5 degrees C, and (b) cannot be stored dry for long (under the present conditions 3 d or longer) at any of these temperatures. Iris flowers were found to be chilling-sensitive, although only at temperatures of about 0.5 degrees C. (C) 2013 Elsevier B.V. All rights reserved.
van Doorn, W. G., Dole, I., Celikel, F. G., & Harkema, H. (2014). Opening of cut Iris x hollandica flowers as affected by temperature, dry storage, and light. Postharvest Biology and Technology, 89, 40-43. https://doi.org/10.1016/j.postharvbio.2013.10.006