Improvement of germination properties in barley (Hordeum vulgare) seeds damaged by Sitophilus oryzae infestation via dielectric barrier discharge plasma treatment

Abstract Insect‑damaged barley seeds typically exhibit poor germination and are often discarded. This study investigated whether dielectric barrier discharge (DBD) cold plasma could improve the germination of partially viable seeds of barley seeds severely damaged by Sitophilus oryzae , to our knowledge, no study has been conducted in this area. Damaged seeds were treated at 13–19 kV for 1–9 min. Although the highest germination potential was observed at 19 kV for 9 min, the 16 kV for 1 min treatment provided the best overall improvement across germination and seedling growth parameters. Under this treatment, germination potential increased by 80%, germination rate by 59%, and vigor index by 51% compared to untreated damaged seeds. Shoot and root lengths increased by 41% and 24%, respectively, while fresh and dry weights also increased significantly. Furthermore, electrolyte leakage decreased by 40%, indicating improved membrane integrity. Plasma treatment roughened the seed surface (SEM), altered O–H and C–H functional groups (FTIR), and reduced the water contact angle from 89.88° to 27.83°, making the surface highly hydrophilic. Color changes were minor (ΔE = 3.99). These results demonstrate that DBD cold plasma, particularly at 16 kV for 1 min, can improve germination and early growth of insect‑damaged barley seeds through surface physical and chemical modifications that enhance wettability and water uptake. This chemical‑free method can offer a practical strategy to add value to otherwise wasted seeds, reducing post‑harvest losses and supporting sustainable agriculture.