Germination of Wheat Seeds Exposed to Cold Atmospheric Plasma in Dry and Wet Plasma-Activated Water and Mist

摘要

We apply different cold atmospheric plasma (CAP) configurations to treat wheat seeds using (1) a direct atmospheric plasma jet (APJ) in the dry form, (2) indirect plasma-activated water (PAW) in the soaked form, and (3) plasma-activated mist (PAMI) in the wet form. Wheat seedling germination parameters including germination potential, germination index, vigor index, and shoot and root lengths are measured for different plasma treatment-time intervals. Seed germination and seedling growth of wheat specimens are enhanced compared to those of untreated controls. Indirect wet PAW and PAMI show higher wheat germination compared to that of dry direct APJ. During plasma treatment, a rise in hydrophilization of seed surface coat is accompanied by increased water uptake of treated seeds. Ozone generated by plasma shows an increase in all discharge conditions, but this increase is reduced for higher relative humidity values in the PAMI mode. During treatment, OH radicals that are generated by APJ increase largely near seed surfaces. Regarding seed germination, PAW shows a larger impact than PAMI. However, PAMI can be considered to be the more practical technique for treating large numbers of seeds at an industrial scale.