The study aimed to investigate the effects of pre-sowing treatments with hydrogen peroxide (H₂O₂), ascorbic acid (AsA), and succinic acid (SuA) on morphological traits and photosynthetic pigments of the amaranth (Amaranthus hypochondriacus L. cv. ‘Kizlyarets’) under drought conditions. The study examined the content of antioxidants (amaranthine and ascorbic acid) in the amaranth leaves under normal and drought conditions. The results showed amaranth seed treatment with H₂O₂ (5 mmol) under optimal conditions increased the seedling height, leaf area, number of leaves, and above-ground weight of the amaranth seedlings compared with the control and two other treatments. However, under drought, the morphological traits and the photosynthetic pigments were lower than the control, except for amaranthine and ascorbic acid. The amaranth seed treatment with AsA (60 mg/l) and SuA (300 mg/l) improved the morphological traits and chlorophyll and carotenoid contents under normal and drought conditions. Thus, the application of AsA and SuA could promote the growth and development of amaranth plants with enhanced drought tolerance.

Keywords: Amaranth (A. hypochondriacus L.), drought stress, hydrogen peroxide, succinic and ascorbic acids, morphological traits, photosynthetic pigments, amaranthine

Key findings: The results revealed applying AsA and SuA promotes the morphological traits and chlorophyll and carotenoid contents along with the general growth and development of amaranth (A. hypochondriacus L.) plants with enhanced drought tolerance.