The Cause of Bent Neck in Cut Roses1

Abstract

Abstract Neck bending in cut roses, cv. ‘Forever Yours’, was shown to be the result of wilting in the pedicel tissue. Four possible mechanisms to account for this occurrence in cut blooms and its absence in intact flowers were investigated experimentally. Both a decline in the diffusion pressure deficit of the tissues and an increase in the stem flow resistance of cut blooms were found to be involved. The increase in water flow resistance was shown to coincide with the appearance of a material plugging the vessels. The role of micro-organisms in the deposition of this material is discussed in relation to the data presented. Compared with those held in water, cut blooms placed in a solution of the bacterio- and fungi-static agent 8-hydroxyquinoline sulphate showed a lower frequency of vessel plugging, a lower stem flow resistance and lasted twice as long prior to the development of bent neck.