Plasma Agriculture

Recently, many kinds of non-equilibrium atmospheric-pressure plasma sources have been developed for medical and agricultural applications. Some sources have been applied to agricultural crops and foods for the inactivation of microorganisms and the acceleration of seed germination and crop growth. In this article, the applications of plasmas to disinfection of agricultural crops and foods are reviewed. Then, a high-density non-equilibrium atmospheric pressure plasma ( NEAPP) applied for inactivating fungal spores of Penicillium digitatum, a difficult-to-inactivate food spoilage microorganism, is introduced as an environmentally safe and rapid inactivation method. The NEAPP employing Ar gas has a high electron density on the order of 10(15) cm(-3). The spores were successfully inactivated with a decimal reduction time in spores (D value) of 1.7 min. The contributions of ozone and UV radiation to the inactivation of the spores were evaluated and concluded not to be dominant. Therefore, the significance of neutral reactive species is suggested in the rapid inactivation using NEAPP.