This paper is aiming to present the atmospheric non-thermal plasma for the germination improving of radish seeds. Plasma generation power and plasma irradiation time were studied in order to obtain the proper conditions for the germination enhancement of seeds. The growth rate was determined by measuring the length of root and dry weight of the plants treated by plasma jet. From the experimental results, it could be confirmed that plasma treatment could enhance the growth rate of radish seeds 9-12 percent of the dry weight of radishes, approximately

Seedling growth enhancement of sunflower seeds by DC atmospheric non-thermal Ar–O ₂ plasma has been proposed. The plasma reactor was simply designed by the composition of multi-pin electrodes bonded on a solderable printed circuit board (PCB) anode. A stable plasma was exhibited in the non-periodical self-pulsing discharge mode during the seed treatment. The experimental results showed that non-thermal plasma treatment had a significant positive effect on the sunflower seeds. Ar–O ₂ mixed gas ratio, treatment time and power source voltage are the important parameters affecting growth stimulation of sunflower sprouts. In this research, the sunflower seeds treated with liters per minute (LPM) of Ar–O ₂ plasma at a source voltage of 8 kV for 1 min showed the best results in stimulating the seedling growth. The results in this case showed that the dry weight and average shoot length of the sunflower sprouts were 1.79 and 2.69 times higher and heavier than those of the untreated seeds, respectively.

The effect of non-thermal air plasma on green oak lettuce farming has been proposed. A gliding arc plasma generator (GAPG) was designed for plasma-activated water (PAW) spray generation. A PAW spray was generated at 8, 10, and 12 kV by a custom-made ac high voltage power supply. Four hydroponic green oak lettuce trays were treated by PAW spray at different conditions for 10 min, three times a day for nine days. The experimental results showed that all the plasma-treated green oak lettuce sprouts had a greater growth rate than the control group. The best condition was found in the PAW spray generated at 8 kV source voltage, which led to the longest average height and width of sprouts of 10.88 ± 0.33 cm and 10.09 ± 0.08 cm, respectively. Moreover, its average dried weight was also significantly greater than that of the control group by 1.69 times. It was found that the concentration of total Kjeldahl nitrogen (TKN), mainly ammonium, was enhanced in every PAW spray condition. However, the highest TKN concentration was found in the 8 kV PAW spray, which was 3.67 times higher than that of the control group. The amount of nitrite (NO ₂ ⁻ ) and nitrate (NO ₃ ⁻ ) in PAW spray was also enhanced but in the opposite trend to TKN concentration. Moreover, the electrical conductivity (EC) and pH levels could be improved by air plasma. It could be confirmed that the plasma treatment could be effectively applied to green oak lettuce farming, and the PAW spray generated by the GAPG could enhance the amount of nitrogenous fertilizer in treated water, which is essential for plant growth stimulation.