Electrostatic treatment of bean seeds

The classical methods of seed treatment make use of chemical substances which are either expensive or harmful to the soil. This paper demonstrates that exposure to the action of a high-intensity electric field can be an effective substitute for the chemical agents. The experiments were carried out on bean seeds (Phaseolus vulgare), naturally infected with Colletotrichum lindemuthianum. Under normal conditions (no treatment), only about 30% of a reference sample of such seeds germinated. Other samples were subjected to 50 Hz electric fields ranging from 2 to 16 kV/cm with exposure time ranging from 1 to 30 s. In the optimum laboratory test, more than 99% of the seeds germinated. The weight of the resulting bean plants was significantly greater than those grown from nontreated seeds. The field tests proved the efficiency of this method, which could be successfully employed for the prevention or treatment of various seed-transmitted diseases of plants. Ozone generation by partial discharges between seeds seems to be the main sterilizing agent, while the activation of OH radicals under the action of the high-intensity electric field may explain the intensification of the biological processes. The automated seed treatment installation proposed in this paper consists of a plate-type capacitor, supplied from a 75 kV 50 Hz generator. Special devices ensure the rapid transfer of the material to and from the seed treatment cell. The method and the apparatus for seed treatment have been patented