Seedling growth response of sesame (Sesamum indicum L.) to PEG-induced drought stress and different boron levels

Sesame (Sesamum indicum L.) is an important oilseed crop; however, its productivity is often adversely affected by drought stress, particularly during the seedling stage. Some micronutrients, such as boron (B), can significantly enhance plants' drought resistance; nevertheless, excessive levels may be toxic. The development of drought-resistant sesame varieties is essential for sustainable cultivation. The purpose of this study was to investigate the effects of drought stress, boron, and the combination of both on sesame seedling traits. Different doses of polyethylene glycol solution (PEG 6000) (PEG) as a drought stress (0; control, -2; P1, and -4; P2 MPa) and boric acid (H3BO3) (B) as a boron source (0; control, 5; B1, and 10; B2 mM) were used to apply to seeds. Drought stress adversely affected sesame seedling growth trait. The increase in PEG levels from 0 to -4 MPa significantly reduced root and shoot length, whereas they did not generate a significant difference in fresh root and fresh shoot weight. Furthermore, the findings indicated that increased B treatments reduced all seedling characteristics in sesame. The overall results indicate that the growth parameters of sesame seedlings were significantly reduced at -4 MPa of PEG and 10 mM concentrations of boron.