2. Materials andmethods
2.1. Plasma reactor and electrical circuit
The seeds were treated by non-thermal plasma using a surface discharge reactor, at atmospheric pressure and room temperature.The set-up is illustrated in Fig. 1.The plasma reactor consists of two electrodes placed on both sides of a glass plate (length 120 mm, width 90 mm, thickness 1.5 mm). The high voltage electrode is an array of 13 copper wires, each wire having a diameter of 100 μmand length of 44 mm. The distance between adjacent wires was 6 mm. The ground electrode was an aluminium tape (length 90 mm, width 48 mm). The seeds were distributed uniformly
on each wire. The plasma reactor was placed in a rectangular case and air was flown with a rate of 1 L/min.The dischargewas generated in a.c.mode using a high voltage transformer
(TIRB 0–20, Electroputere, Romania, transformation ratio 300),