When excised flowers were treated with 1-MCP and left in water
at 25
◦
C, the time to petal senescence was approximately 30 d
(Table 1). If the flowers were not treated with 1-MCP the time to
senescence was about 10 d. Treatment with ethylene, for 24 h at
25
◦
C, reduced the time to senescence, counted from the end of
ethylene treatment, to5d(Table 1). After ethylene treatment and
in controls, the first visible symptoms were showing of the vascular bundles as darker coloured against the background colour of the
petals. This is called venation. It was observed within 24 h after the
end of ethylene treatment. Folding of the petals, known as drooping, occurred within 18 h after the ethylene treatment had ended.
Subsequently, the petals showed water soaking, at day 5. This was
considered the first symptom of senescence. Water soaking was followed, within about a day, by browning, and then by desiccation.
In untreated flowers the same senescence symptoms were found,
occurring in the same order, but at a later point in time (water
soaking after 10 d, browning after about 12 d, and desiccation after
about 14 d). After 1-MCP treatment, the petals showed desiccationrather than the senescence symptoms that were caused by ethylene
treatment.