Ethylene, MCP and bulb flowers
Tulip, alstroemeria and gladiolus

Ethylene inhibited stem elongation in tulips. This is a known effect, but ethylene also appeared to promote earlier senescence so that flowers lost weight more rapidly than controls. MCP appeared to promote stem elongation but did not retard weight loss.

Alstroemeria are know to be an ethylene sensitive flower but there was no visble effect of ethylene or MCP on the stems in our experiment. Effects might have been obscured by the presence of so many flowers at different stages of devlopment on each stem.

In Gladiolus ethylene seemed to promote flower opening early in the experiment, but treated flowers lost weight more rapidly than controls. By contrast, MCP seemed to delay flower opening and trated flowers maintained fresh weight longer than controls. These effects were not reversed by ethylene after MCP treatment.