The Effect of Liquids Activated by Plasma Generated with a Microwave Plasmatron and High-Frequency Glow Discharge on...

In this study, we investigated the effect of plasma-activated liquids (PAL) on the cotton plant (Gossypium hirsutum L.) growth under laboratory and field conditions. We used two types of PAL: deionized water activated with plasma generated using a microwave plasmatron in atmospheric-pressure air flow (PAW) and a 1.5% KNO₃ solution activated using plasma generated in an electrochemical cell (PAKNO₃). These treatments differ in terms of their content of long-lived biologically active compounds. PAW contains a higher concentration of hydrogen peroxide (150 μM compared to 1.1 μM), while PAKNO₃ is more saturated with NO₂^- and NO₃^- (1510 μM compared to 300 µM). We found that PAW improved cotton plant growth under field conditions and in a laboratory drought stress. Additionally, PAW increased field emergence and germination of heat-treated cotton seeds in the laboratory. It was revealed that PAW prevents the drought-induced disruption of the partitioning of absorbed light energy in the photosynthetic apparatus. Meanwhile, PAKNO₃ has a positive effect on seed germination. The positive effect of PALs on cotton seeds and plants is thought to be due to the generation of long-lived biologically active oxygen and nitrogen species during plasma treatment of the liquid.