Electrohydraulic Discharge Induced Gas-Liquid Interface Plasma for Seed Priming in Hydroponics

Seed priming is a vital process in agriculture, improving germination and uniformity.This study presents an innovative seed priming approach using electrohydraulic discharge plasma (EHDP) techniques inducing gas-liquid interface plasma on wet seeds-EHDP-wet seed surface priming-and on seeds submerged in water-EHDP-immersed seed priming.These techniques were applied to green oak leaf lettuce (Lactuca sativa L.) seeds.The results show that EHDP-immersed seed priming significantly enhances germination rate (98.3%, compared to a control of ~80%), germination uniformity (~5 hrs compared to a control of ~15 hrs), and Mean Germination Time (MGT) (~1.87 days compared to a control of ~2.5 days).The presented method exploits three primary plasma formation regions, each generating distinct reactive oxygen and nitrogen species (RONS) and ions that interact differently with the seeds.RONS, particularly hydrogen peroxide (H 2 O 2 ), nitrate (NO 3 -), and nitrite (NO 2 -), play crucial roles in germination, vigor, nutrient uptake, and hormonal regulation, thereby effectively breaking seed dormancy.Potential plasma treatment damages were addressed, revealing no significant variations in plant height, root length, leaf diameter, leaf thickness, or leaf numbers between control and plasma-primed groups, affirming EHDP plasma priming safety.This study underscores EHDP plasma priming's potential to enhance seed germination and early plant growth while reducing contamination risks without negatively impacting plant health and development, indicating a transformative potential for the agricultural industry.