Fig. 4

Effects of light sources on the SPAD value (A), chlorophyll a (Chl a) (B), chlorophyll b (Chl b) (C), the sum of Chl a and Chl b (D), ratio of Chl a to Chl b (E), and carotene content (F) of each true leaf. Each value is a mean of five replicates ± standard deviation (SD). Different letters indicate significant differences at P < 0.05