Optimizing beet seed germination via dielectric barrier discharge plasma parameters

Abstract

This study explores the synergistic effects of gas composition and electric field modulation on beetroot seed germination using dielectric barrier discharge (DBD) plasma. The investigation initially focuses on the impact of air plasma exposure on germination parameters, varying both voltage and treatment duration. Subsequently, the study examines how different gas compositions (argon, nitrogen, oxygen, and carbon dioxide) affect germination outcomes under optimal air plasma conditions. Results indicate that plasma treatment significantly enhances germination rates and seedling growth relative to untreated controls. Notably, plasma exposure alters seed surface morphology and chemistry, increasing roughness, porosity, and hydrophilicity due to the formation of new polar functional groups. The highest germination rate (a 54.84 % increase) and germination index (a 40.11 % increase) were observed at the lowest voltage and shortest duration, whereas higher voltages and prolonged exposure reduced germination, likely due to oxidative stress. Among the tested gas environments, air plasma was most effective in enhancing water uptake and electrical conductivity, while oxygen plasma resulted in the highest germination index and marked improvements in root and shoot length. Conversely, carbon dioxide plasma treatment exhibited inhibitory effects on both germination and subsequent growth metrics. The results highlight the potential of DBD plasma technology to enhance agricultural productivity by optimizing seed germination and early growth. The study emphasizes the importance of precise parameter tuning, particularly gas composition and plasma exposure conditions, to maximize benefits while minimizing adverse effects, offering a refined approach to seed priming in agricultural practices.