A prototype of a DBD device that generated non-thermal plasma, was constructed (Fig. 1). This prototype was designed for treating three to fierice seeds at a time under room tem perature (~25°C) and atmospheric pressure at a 3 W discharge power. A cylindrical aluminum rod (25.4 mm in diameter and length) was used as the powered electrode in the DBD device. The powered electrode was placed in a polyetherimide shell (50.8 mm in diameter and 76.2 mm long) for electrical isolation. A quartz disc (50.8 mm in diameter and 1.6 mm thick)
was attached underneath the powered electrode to serve as the dielectric barrier in this DBD device. The air under the insulated powered electrode served as the working gas for plasma generation. Seeds or cultures of G. fujikuroi were placed on an aluminum holder that was electrically grounded. A high volt age (30 kV at the peak amplitude) and low frequency (22 kHz sinusoidal waveform) was applied to the powered electrode. Filamentary discharges with a diameter of 100 to 300 μm (Kogel schatz, 2003) were produced between the dielectric barrier and the sample and also between the dielectric barrier and the aluminum holder. The duty cycle of the power supply was set at 6% to reduce the temperature produced by the air DBD.