Table 3.

Effect of ${\mathrm{NO}}_{\mathrm{3}}^{\mathrm{-}}$:Cl^- ratio on total phenols, total flavonoids and ferric-reducing antioxidant power (FRAP) in leaves of cardoon plants (Cynara cardunculus L. var. altilis DC) harvested at different days after sowing (DAS); cardoon plants were grown in a floating system under greenhouse conditions (Experiment 1).

Treatment	Total phenols (mg gallic acid g-1 DW)			Total flavonoids (mg quercitin g-1 DW)			FRAP (μmol FeSO4 g-1 DW)
${\mathrm{NO}}_{\mathrm{3}}^{\mathrm{-}}$:Cl-	45 DAS	73 DAS	101 DAS	45 DAS	73 DAS	101 DAS	45 DAS	73 DAS	101 DAS
80: 20	7.63	13.97	17.22	3.27	21.36	38.16	92.52	217.20	290.97
60: 40	9.03	15.04	19.34	6.97	24.69	45.89	117.11	247.37	318.04
40: 60	9.51	16.35	19.74	7.26	29.94	44.79	125.46	283.88	322.17
20: 80	10.59	22.09	21.03	8.82	49.55	54.62	144.65	390.45	371.98
Significance	L*	L**	L*	L*	L*	NS	L*	L***	NS

L, linear; NS, non-significant; *P < 0.05; **P < 0.01; ***P < 0.001.