Efficiency of germination inhibition after treatment of an air-water plasma jet: the effect of pulsating DC power

Abstract

Pulsating direct current (PDC) power consisting of AC power and a diode connected in series was adopted to produce an atmospheric pressure plasma jet. The PDC power is a high-voltage half-wave rectified AC power. During the experiments, the gas temperature of the PDC plasma was in the range of 45.0 °C–59.7 °C. P. digitatum spores spread on a glass slide were directly treated by the plasma plume and a germination inhibition rate was adopted to evaluate the inhibition efficiency. In order to ensure that the plasma plume touched as many spores as possible, the glass slide was fixed on a programmable 3D mobile platform and moved in a zigzag path during the treatment process. The maximum germination inhibition rate reaches 0.701 by the PDC plasma jet at a discharge current of −7.5 mA and water content of 9.58 mg l−1.