Effect of time since harvest and handling conditions on rehydration ability of cut chrysanthemum flowers
U. van Meeteren and H. van Gelder
Postharvest Biology and Technology Vol: 16 Issue: 2 Pages 169-177.
1999
บทคัดย่อ
Fresh cut chrysanthemum (Dendranthema x grandiflorum `Cassa') flowers
rehydrated fully after rapid water loss over 1 h at 20°C, 60%
relative humidity (RH), and 14 
mol·m-2·s-1
light, the water loss being 5% of their fully saturated fresh weight. For
rehydration after desiccation, it proved important that flowers were cut at a
minimum distance above soil level. The water status of cut flowers dry-stored
in darkness for 24 h at 20°C with minimal water loss
(~1%) decreased sharply during the first days of subsequent vase life. Flowers
stood for 3¯4 h in 20°C water and at low light
intensity (14 mol·m-2·s-1)
followed by `desiccation' did not rehydrate after the desiccation, but
decreased further in fresh weight when returned to water. Rehydration ability
of these flowers was restored, however, when the stem ends were trimmed by 7 cm
under water after desiccation. Recutting in air did not restore rehydration
ability. After periods of 4 or 24 h at 20°C in 5°C water at
low light intensity followed by desiccation, flowers regained their water
status during subsequent vase life. Flowers stood for 24 h in 20°C
water and at high light intensity (187 mol·m-2·s-1)
followed by desiccation rehydrated almost fully when returned to water. It is
proposed that an undefined `rehydration-inhibiting' process starts after
harvest, which is not due to dehydration of xylem walls or other stem tissue,
or to the growth of microorganisms.