Table 3.

The maximum quantum yield of photosystem 2 (PS2) photochemistry (Fv/Fm), effective quantum yield of PS2 (ФPS2), photochemical quenching (qP), non-photochemical quenching (qN), effective quantum yield of photochemical energy conservation in PS2 (Fv′/Fm′) and electron transport rate (ETR) of P. vulgaris seedlings under different water (W) and fertilization (F) regimes

Treatment	Fv/Fm	ФPS2	QP	QN	Fv′/Fm′	ETR
W1/F0	0.80 ± 0.03 b	0.18 ± 0.02 c	0.46 ± 0.06 c	1.82 ± 0.06 ab	0.39 ± 0.01 e	90.45 ± 4.26 c
W1/F1	0.84 ± 0.01 a	0.26 ± 0.01 b	0.62 ± 0.02 ab	1.91 ± 0.04 a	0.43 ± 0.01 cd	131.12 ± 3.74 b
W1/F2	0.82 ± 0.01 a	0.24 ± 0.04 b	0.58 ± 0.05 b	1.91 ± 0.14 a	0.41 ± 0.03 de	114.19 ± 20.03 b
W2/F0	0.80 ± 0.01 b	0.26 ± 0.01 b	0.58 ± 0.01 b	1.64 ± 0.03 c	0.45 ± 0.02 bc	92.56 ± 9.95 c
W2/F1	0.84 ± 0.01 a	0.32 ± 0.01 a	0.68 ± 0.00 a	1.75 ± 0.03 bc	0.48 ± 0.01 a	168.02 ± 7.14 a
W2/F2	0.83 ± 0.01 a	0.30 ± 0.05 a	0.56 ± 0.17 b	1.69 ± 0.07 c	0.45 ± 0.02 ab	150.70 ± 22.53 a
Water (W)	0.69	56.76**	19.77**	69.68**	110.67**	38.14**
Fertilization (F)	29.97**	25.42**	27.43**	6.87**	14.45**	72.94**
W × F	1.33	0.79	4.56*	0.41	0.58	8.00**

W1 and W2 correspond to soil water contents between 45–50 and 70–75 % of the field water capacity, respectively; F0: no fertilization, F1: 0.12 g N + 0.2 g P₂O₅ + 0.1 g K₂O kg⁻¹ soil, F2: 0.24 g N + 0.4 g P₂O₅ + 0.2 g K₂O kg⁻¹ soil. Different letters indicate significant differences between treatments at P < 0.05 (ANOVA)

Mean ± SD, n = 5, *P < 0.05, **P < 0.01