Effect of spraying with silicon, humic acid, and proline on the safflower tolerance (Carthamus tinctorius L.) to salt stress

Abstract

The experiment was carried out in the winter of season 2021-2022 in the research field of the College of Agriculture - University of Basra (latitude 30.57° North and longitude 47.80°) to study the effect of foliar spraying of silicon, humic acid, and proline on the endurance of safflower (Carthamus tinctorius L.) to salt stress. The experiment was carried out by distributing eight treatments of foliar spraying. Silicon (Si) was sprayed at a concentration of 800 ppm, humic acid (H) at a concentration of 80 ppm, and proline (P) at a concentration of 100 ppm. The studied treatments included control (C), Si, H, P, SiH, SiP, HP, and SiHP) on two soils with salinity (7.63 and 14.24 ds m-1) randomized complete block design with three replicates. The seeds of safflower (Cv. Gila) were planted in the two soils. The results showed significant superiority of the triple treatment (SiHP) in all studied traits, as it recorded the highest mean of height (156.3 cm), number of bells in the plant 59.11, number of seeds in the bell (59.17), weight of 500 seeds (24.30 g), seeds yield (10549 kg seeds ha-1) and biological yield (27582 kg ha-1) with a significant increase over the control treatment, which amounted to 64.2 cm, 26.08 bell plant-1, 24.90 seed bell-1, 14.03 g, 1725 kg seeds ha-1 and 6594 kg.ha-1 respectively—superiority of the proline treatment in all studied traits. Salinity decreased the number of seeds in the plant, the weight of 500 seeds, and seed yield. The foliar spray with the above treatments has proven its effectiveness and efficiency in growth and yield and increased salinity tolerance, in addition to the fact that these materials are environmentally friendly. Keywords: Foliar Spraying; Salinity; Silicon; Humic acid; proline.