On the basis of previous studies, an antioxidant enriched high yield potential genotype (Accession VA13) was selected for this investigation. This genotype was grown in pots of a rain shelter open field of Bangabandhu Sheikh Mujibur Rahman Agricultural University, Bangladesh (AEZ-28, 24° 23′ north latitude, 90° 08′ east longitude, 8.4 m.s.l.). The seeds were sown in plastic pots (15 cm in height and 40 cm length and 30 cm width) in a randomized complete block design (RCBD) with three replications. N: P₂O₅:K₂O were applied @92:48:60 kg/ha as a split dose. First, in pot soil, @46:48:60 kg ha 1 N: P₂O₅:K₂O and second, at 7 days after sowing (DAS) @46:0:0 kg/ha N: P₂O₅:K₂O. The genotype was grouped into three sets and subjected to four salinity stress treatments that are, 100 mM NaCl, 50 mM NaCl, 25 mM NaCl, and control or no saline water (NS). Pots were well irrigated with fresh water every day up to 10 days after sowing (DAS) of seeds for proper establishment and vigorous growth of seedlings. Imposition of salinity stress treatment was started at 11 DAS and continued up to 40 DAS (edible stage). Saline water (100 mM NaCl, 50 mM NaCl and 25 mM NaCl) and fresh water were applied to respective pots once a day. At 40 DAS the leaves of Amaranthus tricolor were harvested. All the parameters were measured in six samples.

At Moderate salinity stress (MSS) and Severe salinity stress (SSS) conditions, leaf color parameters and pigments, vitamins, phenolic acids, flavonoids and antioxidant capacity of A. tricolor leaves were very high compared to control condition. Hence, salt-stressed A. tricolor leaves had a good source of natural antioxidants compared to plant grown in normal cultivation practices.