A Non‐thermal Plasma Seed Treatment Method for Management of a Seedborne Fungal Pathogen on Rice Seed

Abstract

Seeds contaminated with pathogens are the primary inoculum for plant diseases in many food crops. Conventional treatments for seedborne diseases use hot water, chlorine or fungicide applications. A novel seed treatment method based on non‐thermal plasma generated by an air dielectric barrier discharge (DBD) device was evaluated in this study as an alternative to these conventional treatments. The non‐thermal plasma at atmospheric pressure and room temperature consisted of partially‐ionized gases that are chemically reactive. The antimicrobial activity of non‐thermal plasma was evaluated against an important seedborne pathogen, Gibberella fujikuroi, that causes bakanae disease in rice. Non‐thermal plasma treatments effectively inhibited the growth of G. fujikuroi on nutrient growth medium and reduced the number of fungal colony forming units (CFU) on the rice seed surface by > 92% after 120 s exposure. Effective exposure times to 50% (ET50) and 90% (ET90) control of G. fujikuroi CFU on the seed surface were 9 and 76 s, respectively. Ten minutes of non‐thermal plasma treatment on seeds infested with G. fujikuroi significantly reduced disease development. No adverse effects were detected on the seedling emergence and height when non‐infested seeds were treated with non‐thermal plasma for up to 20 min. The treated seeds germinated and grew similarly compared with non‐treated non‐infested seeds. This study indicates that non‐thermal plasma had antifungal activity and showed potential as an effective disinfection technique to reduce the contamination of seedborne fungal pathogens from seed surfaces without compromising seed health.

Effects of Nonthermal Plasma on Wheat Grains and Products

“…e germination of many plant species can be improved by NTP treatment. e positive effect of NTP was found on barley (Hordeum vulgare, [49]), maize (Zea mays, [50]), oat (Avena sativa, [51]), rice (Oryza sp., [52]), spinach (Spinacia oleracea L. Beiouzhizun, [53]), bell pepper (Capsicum annuum L. cultivar California Wonder, [54]), and mung bean [55]. On the other hand, the neutral effect was found on oat germination and early growth [43].…”

Plant Disease Control by Non-Thermal Atmospheric-Pressure Plasma

“…This might be a consequence of the removal of pathogenic microbes or activation of the seed germination process by plasma itself (Randeniya and de Groot, 2015). In many studies, plasma treatment demonstrated no adverse effects on seed vitality (such as germination and subsequent growth) at antimicrobial doses (Selcuk et al, 2008;Jo et al, 2014). These results indicate that the plasma treatment is a quite promising technique for seed disinfection.…”

Water treatment by the AC gliding arc air plasma

“…Generally, oxygen species is one of the most important materials for sterilization which has been mentioned in many reports on plasma sterilization. Atomic nitrogen radiates at 745 nm and N 2 as the other important reactive particle is detected in the range of 320-400 nm [11,12]. Ultraviolet peaks are at 364.5, 388.5, 388.9, and 397 nm and the peaks of NO are at 296, 357.7, and 378.9 nm [13].…”