Pulsing with gibberellic acid followed by continuous sucrose treatment
enhanced flower longevity and flower bud opening in cut
Polianthes tuberosa L. cv. Double. Pulsing with
gibberellic acid at 10 or 20 mg/L plus 8-hydroxyquinoline sulfate (200
mg/L) for 24 h followed by continuous sucrose treatments (4 or 8%)
plus 8-hydroxyquinoline sulfate extended the vase life and significantly
promoted flower bud opening as compared with the 8-hydroxyquinoline sulfate
controls. A pulse with a higher concentration of gibberellic acid (50
mg/L) followed by sucrose solutions did not increase vase life or enhance
flower bud opening greater than those pulsed with gibberellic acid at 10 or 20
mg/L followed by 8-hydroxyquinoline sulfate. A gibberellic acid (10, 20 or
50 mg/L) pulse followed by 8-hydroxyquinoline sulfate holding solution had
little effect on longevity and flower bud opening in comparison to
8-hydroxyquinoline sulfate controls. Similarly, continuous sucrose treatment
at 4 or 8% without a gibberellic acid-pulsed treatment also showed
little effect on vase life and flower bud opening. Cut
P. tuberosa treated with a gibberellic acid pulse
followed by 8-hydroxyquinoline sulfate produced more ethylene than those
treated with 8-hydroxyquinoline sulfate alone. Ethylene production from
flowers pulsed with gibberellic acid followed by sucrose was low when compared
with controls or those pulsed with gibberellic acid alone. Cut stems
continuously placed in solutions containing sucrose produced less ethylene
than those without sucrose. It is suggested that a gibberellic acid pulse at
10 mg/L followed by continuous sucrose treatment at 4% be
recommended to growers for extending the vase life and enhancing flower bud
opening in cut P. tuberosa.
Challenging a concept: Pulsed treatment regimen—No risk of PML?