Plasma-Activated Water Produced by a Moderately High Energy-Efficient 1-Liter Reactor: Effects on Germination and Growth of Tomato and Bell Pepper Plants

Abstract

Plasma-activated water (PAW) is a sustainable and innovative alternative foragriculture, especially in controlled environments like greenhouses. Tomato and pepperare key horticultural crops worldwide, with a considerable part of their production ingreenhouses. This study examined the effects of PAW irrigation on seed germination, plantgrowth, and oxidative stress in tomato and bell pepper plants. PAW was activated for up to15 min using a 1 L capacity plasma reactor based on a glow-type discharge in air with water-cathode. The concentration of nitrogen compounds and the energy efficiency of synthesisobtained with the reactor were moderately high (5.4 mM and 60 nmol/J, respectively). Themost notable effects of PAW were observed in bell pepper. The germination percentagein bell pepper increased by up to 26%, while no significant effects were found in tomatoseeds. PAW irrigation significantly promoted plant growth, with dry weight increasingby up to 61% in bell pepper and 42% in tomato. Lipid peroxidation results showed nooxidative damage in either crop. The biochemical analysis of antioxidant enzymes (catalase,superoxide dismutase, and guaiacol peroxidase) confirmed that plant defense systemsresponded adequately to PAW irrigation. These results highlight PAW’s potential as aninnovative and eco-friendly alternative in agriculture.