Scientists at Novosibirsk State Technical University (NSTU) are improving the method of treating seeds with corona discharge current. The selection of optimal process parameters will increase the efficiency of pre-sowing preparation and reduce energy consumption.
High-quality seeds are one of the main factors in increasing crop yields. There are different methods of seed preparation: heating, soaking, chemical pickling. One of the promising methods, characterized by high efficiency and safety, is the pre-sowing treatment of seeds with a corona discharge current.
As explained by Evgeny Porsev, Doctor of Technical Sciences, Professor of the Department of Electrotechnical Complexes at NSTU-NETI, during this treatment, the seeds pass through a high-voltage electric field created between the electrodes. The current density is minimal, on the order of 1-3 A/m2, but this is sufficient to suppress the viability of pathogens living on seeds due to the thermal action of corona discharge electric current flowing through the bodies of myco- and microflora spores. This effect makes it possible to get rid of the harmful effects of pathogens on crop seedlings. This treatment method ensures disinfection of seeds, which reduces the risk of diseases of seedlings. They can be used to process seeds of various crops, both grain and vegetable. Unlike chemical etching, this method does not leave toxic traces in the soil and in future crops, requires low energy consumption, and processing is fast.
Previously, in order to confirm the effectiveness of the method, experiments were conducted on barley and wheat, which showed that when treated with a corona discharge electric current with a field strength of 500-312 kV/m and a low current density (0.0043–0.0098 A/m2), the germination rate increased by about 3%, and the yield increased by 16-19% to the yield at the control site.
NSTU-NETI scientists, improving this method, experimentally selected the optimal angle of inclination of the precipitation electrodes in order to increase the productivity of the plant for pre-sowing seed treatment. This is important because a slope that is too steep reduces the time of exposure to the electric field on the seeds, and a slope that is too shallow reduces the capacity of the plant.
"We selected a material for corona electrodes that is resistant to electrical erosion in order to extend their service life in seed treatment plants. We also searched for the parameters of the optimal electric field strength in the discharge gap, that is, we varied the gap between the electrodes. This is necessary to create a certain tension in the
electric field, which ultimately affects the cost of the installation," said Evgeny Porsev.
At the next stage, experiments will be conducted to determine the optimal parameters of electrocorning treatment for various types of seeds. Such key parameters are the electric field strength, processing time, and current density of the corona discharge.