Efficacy of periodic cold plasma treatment in a paddy to produce white-core grains in brewer’s rice cultivar Yamadanishiki

Abstract

We investigated the effect of cold plasma application on the yield and grain quality of rice (Oryza sativa L.), focusing on the brewer’s rice cultivar, Yamadanishiki. Two treatment methods were examined in a paddy; direct plasma irradiation of seedlings and indirect treatment with plasma-activated Ringer’s lactate solution (PAL) during the vegetative growth phase. Periodic direct irradiation for 30 s increased whole plant weight and grain yield. Treatment with PAL promoted some growth of panicles relatively and partially suppressed the growth of culms and leaves. Both treatments affected the grain quality; an increase of the ratio of white-core grains to total number of grains, which is suited for producing Japanese sake rice, as well as a decrease of the ratio of immature grains. The results showed that the effective production of rice grains for sake production can be improved by the application of cold plasma treatment of rice seedlings in a paddy.

Highlight

• Rice plants of brewer’s rice cultivar in a paddy were treated with cold plasma, by the direct irradiation of plants and the immersed of plants in plasma-activated Ringer’s lactate (PAL).

• Direct plasma irradiation promoted plant weight, grain ripening, and increased yield.

• PAL treatment affected the growth of main stem and promoted the growth of panicles relatively.

• Both treatments improved the producing white-core grains, in addition to promotion of grain ripening.

• Cold plasma treatment can be applied to produce stable and high-quality food in various agriculture and food industries, which can achieve the sustainable developmental goals (SDGs).

Keywords:

• Cold plasma
• application to agriculture
• plant growth enhancement
• improvement of yield
• reactive oxygen and nitrogen species

Acknowledgements

Shinya Mizuno, Masaaki Kuge, Dr. Yoichi Morinaka, and many staff members at the Togo Field for Science and Education of Nagoya University are thanked for their technical support with the cultivation of rice plants. Dr. Hiroyuki Kano and Yoshihiro Nakai maintained the plasma devices for use in paddy fields. Prof. Masafumi Ito from Meijo University and his students provided generous support with the plasma treatment conducted in paddy fields. Akitoshi Itoh from Food Research Centre, Aichi Centre for Industry and Science Technology, and Susumu Nikawa provided valuable advice regarding the direction of our research.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported financially by Fujitsu Client Computing Limited and JSPS KAKENHI [Grant No. JP19H05462].