GA3 was also applied as a pulse treatment prior to vase life in water. A pulse for 3–12 h at 0.45 mM delayed the time to petal blackening by 1.1–2.0 d (Table 4). No difference was found between the 3 h or longer period of application (Table 4). The experiments were carried out in April and December.
Thidiazuron was also used as a pulse treatment. Pulsing for 3 h with an aqueous solution containing 5 or 10 M TDZ delayed petal blackening by about 1.5–2.0 d (Table 4). A 6 or 12 h pulse also delayed the time to petal blackening to 2.0 d (Table 4). Further tests showed a similar 2 d delay of petal blackening after pulsing for 3 h with 20, 30 or 40 M TDZ (data not shown). The experiments in which TDZ was applied as a pulse treatment were carried out in January and March.