Abstract / Summary
Non-thermal plasma (NTP) is an emerging technology in different areas, including agriculture, and scaling it requires understanding its physical and chemical interactions with tissue. This study evaluated the physiomorphic, thermodynamic, and electrodynamic interplays between an air-based double dielectric barrier discharge (DDBD) plasma and the structure of two maize (Zea mays L.) genotypes: white (PBB-DH-183) and yellow (H-394 A). Electrodynamic characterisation confirmed a filament discharge with a power of 22.5 W. Long-wave infrared (LWIR) thermographic profiling demonstrated that the surface temperature of the caryopses stabilised at 25.0 °C (ΔTemp = 4.7 °C), assuring a non-thermal regime and indicating that non-thermal electric and electrochemical interactions drive cellular responses. Tests revealed an exposure-time-dependent, non-linear hormetic response. A 60 s window optimised germination efficiency (GE) in the white genotype, achieving a net increase of +7.02% at the M position (embryo-up orientation), an effect attributed to physical surface etching that accelerates water imbibition. Conversely, yellow maize reached its maximum GE (+3.22%) at 60 s under the N position (endosperm-up orientation), where the starch matrix acts as a shield. Overexposure (≥120 s) induced significant distress and phytotoxicity, collapsing the primary seminal root by −16.9% (white) and −36.0% (yellow). Optimising NTP relies on adjusting the kinetic windows to account for tissue anisotropy, dielectric properties, and genotypic sensitivity.