Water Stress as the Cause for Failure of Flower Bud Opening in Iris1

Abstract

Abstract Flower opening failure was encountered in cut iris flowers (cvs. Wedgwood and Prof. Blaauw) stored at low temperature for 4 days, then held for an additional day at 22°C. The cause was found to be water stress in the flowers as a result of a stem blockage developing during storage and shipment. In flowers harvested with the basalplate of the bulb attached to the stem, the plug apparently develops up into the stem. This failure of flower opening was overcome by pre-shipment cutting of the base of flowers harvested without the basalplate and conditioning in warm water. Conditioning with a preservative solution improved coloration. A new method for water flow resistance measurement in stem sections is described.