ENHANCEMENT OF SOYBEAN (GLYCINE MAX VAR. JS-9560) GROWTH AND YIELD AFTER PRE-SOWING TREATMENT OF SEEDS USING NON-THERMAL PLASMA OF DIFFERENT GASES

Pre-sowing treatment of seeds with non-thermal plasma of different gases has been studied on the growth and yield of soybean (Glycine max var. JS-9560) under field conditions for two consecutive years (2022 and 2023). Five types of gases, N2, He, Ar, H2, and O2 were used to create plasma in a cylindrical vacuum container with an RF power supply. Soybean seeds were exposed to plasma for 15 seconds at 80 W. Growth measurements were taken at 30, 60, and 90 days after sowing the seeds. Plasma treatment improved germination, plant height, leaf area, and plant fresh weight at all the stages of the vegetative growth period. N2 and He plasma were most effective in promoting growth and biomass compared to Ar, O2, and H2. The yield parameters in terms of the number of pods, number of seeds, and 100 seed weight were improved to the extent of around 60 % by N2 and He plasma. Other gases (Ar, H2, and O2) were less beneficial in increasing the yield. Pre-sowing treatment of seeds with plasma especially with N2 and He would be highly beneficial for enhancing the yield of soybean at the field level. The characterization of soybean seeds was conducted using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and optical emission spectroscopy (OES). SEM analysis showed significant changes in nitrogen, helium, argon, oxygen, and hydrogen plasma treated seeds, indicating alterations on the surface of the starch caryopsis, resulting in large channels and pores. FTIR spectroscopy indicated modifications after exposure to plasma-treated seeds, suggesting surface activation due to lipid breakdown. OES detected OH, NO, O, and N2 radicals during plasma treatment, contributing to the optimal outcome.