Effect of Atmospheric Pressure Multicorona Air Plasma and Plasma-Activated Water on Germination and Growth of Rat-Tailed Radish Seeds

The atmospheric pressure multicorona plasmas and plasma-activated water (PAW) have been used to improve the germination and growth of rat-tailed radish seeds (Raphanus sativus var. caudutrus). The multicorona plasmas at 30 kV were used to treat the seeds for 2 and 4 min. The PAW activated by multicorona plasmas (for 1, 5, and 10 min) was then used to soak the plasma-treated seeds for 4 h. The plasma-treated seeds were watered with PAW daily for 7 days. The nonactivated tap water (NAW) was used to soak and water the plasma-treated seeds as a control group. The germination rate, stem length, and the dry weight of all plasma-treated groups are greater than those in the control group. All measurements were increased with increasing PAW times. The highest germination rate of 92% was found in the seeds exposed to plasma for 2 and 4 min with watering 10-min PAW. This germination rate was higher than that in the control group by 10%. This was because the reactive species in plasma and PAW could stimulate the germination rate by increasing water absorption. The highest stem length of 74.76 mm/seedling and dry weight of 14.66 mg/seedling were found in the seeds exposed by plasma for 4 min with watering 10-min PAW. These measurements were higher than those in the control group by 78.42% and 21.66%, respectively. This was because the increase of water absorption and reactive nitrogen species in PAW could stimulate seedling growth. From the observed results, it can be concluded that the increase in plasma treatment times and PAW activated by plasma treatment times on seeds led to a positive effect on seedling growth. Therefore, the atmospheric pressure multicorona plasma and PAW can be considered as an environmentally friendly and innovative tool to enhance the germination and growth of rat-tailed radish seeds.