Low-pressure and atmospheric plasma treatments of sunflower seeds

In development of plasma biotechnology for applications in agriculture and medicine, we investigated plasma treatment effects on crop seeds. Sunflower seeds were treated with three different types of plasma, i.e. low-pressure plasma, dielectric barriers discharge plasma and jet plasma. The plasma was characterized using optical emission spectroscopy for understanding of physical and chemical species in the plasma. Plasma-treated seeds were studied for the plasma effects on both physical and biological properties, including the surface morphology and roughness, contact angle, water absorption rate, germination rate, survival rate and growth rate, etc. In general, with increasing of the plasma power, the seed surface roughness increased, the contact angle decreased and thus the wettability increased, the water absorption depended on the power, and the germination and growth rates increased to maximum under certain plasma parameters. The plasma bioeffects are discussed in association with the physical effects.