Comparison of the Impacts of Three Types of Plasma-Activated Water on the Seed Germination and Plant Growth of Lettuce (Lactuca sativa)

Abstract: Cold air plasma typically generates reactive oxygen and nitrogen species (RONS), which are transported into water to produce plasma-activated water (PAW). This study examines the effect of PAW produced by three different plasma systems on lettuce: transient spark, fountain dielectric barrier discharge, and microwave plasma. Physiochemical PAW properties and concentrations of RONS (ozone, hydrogen peroxide, nitrite, and nitrate) were measured. Seed germination parameters were recorded in 8-day paper tests. The effect of PAW irrigation was investigated after 6 weeks of plant growth in the soil by measuring the germination rate, plant and root length, dry and fresh plant weight, number of leaves, and photosynthetic pigments. PAW, dependent upon its RONS contents, enhances plant development and affects its physiological parameters.