GA3 at 0.45 mM and TDZ at 5 M were

GA3 at 0.45 mM and TDZ at 5 M were also applied separately and together, as a 3 h pulse treatment. The delay of petal blackening (about 2 d) was the same in the separate and in the combined treatment (Table 4). These experiments were carried out in December. An experiment carried out in August showed a small and identical positive effect of these two compounds, applied separately, as blackening was delayed by 0.5 d. The effect on blackening of the chemicals applied together was the same as that of the compounds given separately (data not shown).