Figure 4.
The effects of different treatments on maximum quantum yield of the PSII primary photochemistry (Fv/Fm; A), the efficiency of excitation energy capture by PSII (F′v/F′m; B), the quantum yield of PSII electron transport (ΦPSII; C), and non-photochemical quenching (NPQ; D) in leaves of tomato plants. Supplemental lighting from the underneath canopy (USL) or from the inner canopy (ISL) was applied to plants from the time of transplantation while a no supplemental lighting condition was considered to be the control (CK). Parameters were measured on the second terminal leaflets of leaves on the fifth youngest node for each treatment. Means ± SE (n = 8) different letters indicate significant differences at P < 0.05 according to Duncan's multiple range test.