Fungicidal Effect of Apokampic Discharge Plasma Jet on Wheat Seeds Infected with Alternaria Sp. and Bipolaris Sorokiniana Shoemaker

Atmospheric pressure plasma jets generated by apokamp discharge (APPJ AD) in ambient air was investigated for the improvement of growth parameters of spring wheat seeds («Irgina» cultivar) and for inhibition of potentially phytopathogenic fungi on seeds surface. In case of APPJ AD, active forms of oxygen and nitrogen (as well as the radiation of molecules) are formed in the air of atmospheric pressure, which increases their concentration in the streamer head by orders of magnitude, compared to traditional APPJ based on inert gases. Owing to this, we believe to concentrate action of active forms of oxygen and nitrogen in situ, on the biological target. In our case, this can intensify the processes of inactivation of microscopic mold fungi on the surface of seeds. We tested our hypothesis on wheat seeds infected with helminthosporiosis ( Bipolaris sorokiniana Shoemaker ) with a degree of infection of 50% and early blight ( Alternaria sp. ), whose infection rate was 10%. In the first case, the seeds were treated by apokamp plasma for 1 and 10 minutes. It provided a significant reduction in the degree of infection of seeds with helminthosporiosis by 1.7 and 2.3 times. In comparison with check variant, the treated seeds maintained high rates of viability and germination energy. In the second case, it was possible to completely inactivate alternariosis pathogens within 3 min of treatment. In addition, it is shown that the action of APPJ AD caused a statistically valid elongation of the roots of wheat seedlings. A hypothesis is proposed to explain the found effects. The potential advantages of APPJ AD in the task of seed surface treatment in comparison with other known atmospheric plasma techniques are discussed.