Under the criteria we used to evaluate
floret sensitivity to ethylene (percentage of
petal abscission), it did not appear that stock
plant treatment with ethephon predisposed
plants to higher rates of petal abscission when
exposed to ethylene. Our results support previous
experiments indicating that zonal geraniums
are sensitive to ethylene. All four cultivars
exhibited increased petal abscission
over controls within 1 h of exposure to ethylene.
The ethylene action inhibitor, 1-MCP,
proved effective at decreasing rates of petal
abscission after exposure to ethylene.