Figure 6.

Relative maximal and minimum chlorophyll fluorescence (F_m/F₀) (A), maximum efficiency of the water oxidation reaction (F_v/F₀; B), maximal quantum yield of PSII efficiency (F_v/F_m; C), and performance index on the basis of light absorption (PI _abs; D) (equations and explanations in Table 2) of chrysanthemum cuttings exposed for 30 d to different light quality regimes (red (R), red and blue (R:B), red, blue and far-red (R:B:FR), white (W) and blue (B); see the spectrum in Figure 9). During the experiment, the photosynthetic photon flux density was set to 150 ± 5 µmol m⁻² s⁻¹. Six replicate plants per treatment were assessed. Columns with the same letters are not significantly different at p ≤ 0.05, according to Duncan′s multiple range tests. Bars represent SEM.