. 2017 Feb 7;8:131. doi: 10.3389/fpls.2017.00131

Table 4.

Analysis of variance and mean comparisons for SPAD index and maximum quantum use efficiency PSII in dark-adapted stage of leaves at different days after transplanting (DAT) from lettuce plants grown with different nutrient solutions and biostimulants.

Source of variance	SPAD index			Maximum quantum use efficiency PSII (F_v/F_m)
	13 DAT	20 DAT	36 DAT	13 DAT	20 DAT	36 DAT
Nutrient solution (N)	^∗∗	^∗∗∗	^∗∗∗	^∗∗∗	^∗∗∗	^∗∗
Biostimulant (B)	^∗∗∗	^∗	^∗	^∗∗	ns	^∗
N × B	ns	ns	ns	ns	^∗	ns
Nutrient solution
Standard	34.9^a	36.4^a	34.4^a	0.79^a	0.87	0.86^a
Alkaline	31.2^b	35.6^a	33.7^a	0.78^a	0.86	0.86^a
Saline	31.0^b	31.4^b	28.8^b	0.74^b	0.81	0.81^b
Biostimulant
No application	28.3^c	33.2^b	30.0^c	0.75^b	0.84	0.83^b
Tablet	33.4^b	34.4^ab	32.8^b	0.78^a	0.85	0.84^ab
Tablet + PH	35.4^a	35.8^a	34.2^a	0.79^a	0.85	0.85^a
N × B
Standard solution without biostimulant	29.4	35.4	33.9	0.77	0.86^a	0.85
Standard solution + Tablet	36.9	36.0	34.2	0.80	0.87^a	0.86
Standard solution + Tablet + PH	38.5	37.8	35.2	0.81	0.87^a	0.87
Alkaline solution without biostimulant	28.7	34.6	31.1	0.76	0.86^a	0.85
Alkaline solution + Tablet	31.4	35.3	34.6	0.78	0.86^a	0.86
Alkaline solution + Tablet + PH	33.5	37.0	35.5	0.79	0.87^a	0.86
Saline solution without biostimulant	26.8	29.6	25.1	0.71	0.79^b	0.78
Saline solution + Tablet	32.0	31.9	29.5	0.75	0.83^ab	0.81
Saline solution + Tablet + PH	34.1	32.7	31.9	0.77	0.82^ab	0.83

ns, ^∗, ^∗∗, ^∗∗∗ Non-significant or significant at P ≤ 0.05, 0.01, and 0.001, respectively. Different letters within each column indicate significant differences according to Duncan’s multiple-range test (P = 0.05). Tablet = microbial-based biostimulant ‘Click Horto’ containing 200 spores/tablet of R. irregularis BEG72 plus 4.5 × 10⁷ CFU/tablet of T. atroviride MUCL45632; PH = plant derived-protein hydrolysate ‘Trainer.’