Enhancement of wheat seed germination using double dielectric barrier discharges with electrodes immersed in a conductive liquid

This study evaluates the impact of an innovative dielectric barrier discharge (DBD) system featuring electrodes immersed in a conductive liquid (H₂O + NaCl) and double Pyrex insulation. The experiments used soft, spring wheat (Triticum aestivum) (harvest 2024; lot SPR-2024-TA-079).The results show that the interaction between cold atmospheric plasma (CAP) and the seed surface, at five exposure times (10, 20, 30, 40, and 50 s) and applied voltages (8.27, 8.75, and 9.93 kV), significantly increases the germination rate (up to 97.66%) at exposure times of 20 and 30 s compared to the untreated control group (44.75%). This enhancement is attributed to the controlled generation of reactive oxygen and nitrogen species (ROS/RNS), which improve surface hydrophilicity (minimum contact angle of 40°) and activate key metabolic mechanisms such as seed coat permeabilization and mobilization of energy reserves. However, prolonged exposure times (40 and 50 s) or higher voltages (9.93 kV) reduce efficacy, likely due to oxidative stress and recombination of reactive species. The proposed experimental configuration with electrodes immersed in conductive liquid and a double dielectric barrier improves plasma uniformity, minimizes contamination by metallic particles, and enables modulation of energy density, positioning it as a scalable and sustainable technology for agricultural applications. The findings support the use of DBD as a non-thermal tool to enhance crop performance, aligning with resilient and ecologically intensive agricultural practices. This work lays the groundwork for the development of efficient seed treatment technologies with the potential to reduce agrochemical dependence and contribute to global food security.