Characterization of Plasma Jet for Enhancement of Seed Germination

This study reveals the influence of non-thermal plasma on seed germination employing plasma jet at room temperature for various treatment times. The plasma jet was produced by applying high voltage ac source of 20 kV at frequency 20 kHz. The discharge was characterized using optical and electrical methods. Optical Emission Spectroscopy (OES) was used to analyze the spectra of discharge. Emission spectra of the discharge were measured and analyzed to determine the values of electron temperature (T_e) using line intensity ratio method. The electrical characterization of the discharge was carried out by the measurement of electron density (n­­_e) which was determined using current-density method. Seeds were subjected to non-thermal plasma for various exposure periods. The flow rate of argon was maintained at 2 litre/min. Exposing seeds to plasma for suitable time resulted in increase in final germination percentage, germination index and mean germination time. The contact angle of treated seed was found to be decreased and surface energy was found to be increased. Similarly, water uptake of seeds was also examined. There was an increment in water uptake in plasma treated seeds. Hence, the overall results in this study showed that seeds being treated by plasma jet for suitable treatment time had positive impacts on germination of seeds.

Keywords: Discharge, Electrical Characterization, Non-Thermal Plasma, Germination Index, Mean Germination Time, Water Uptake