Effects of plasma irradiation using various feeding gases on growth of Raphanus sativus L

In this work, we have studied the action of dielectric barrier discharge (DBD) plasma irradiation using various feeding gases on seeds of Raphanus sativus L. and analysis their growth. Our experimental data shows that Air, O2, and NO(10%)+N2 feeding gases plasma irradiation enhanced plant growth, whereas N2, He and Ar feeding gases plasma irradiation had little influence on plant growth. Moreover, humid air plasma irradiation was more effective in growth enhancement than dry one. More than 2.3 times faster growth was observed by 3 min air plasma irradiation with 40–90% relative humidity. The reactive species generated by plasma in gas phase were detected using optical emission spectroscopy and in liquid phase by electron spin resonance (ESR) spectroscopy. We concluded that OH and O radicals were key species for plant growth enhancement. •Air, O2, and NO (10%)+N2 gases plasma irradiation enhance their growth.•O2 gas fumigation enhances their growth, while NO(10%)+N2, N2, He, and Ar gases fumigation do not.•3 min irradiation of air gas plasma with 40–90%rh leads to more than 2.3 times faster growth.•OH and O are key species to growth enhancement based on growth enhancement.•Seeds with air plasma irradiation still keep growth enhancement ability for the long storage duration of 17 months.