Inactivation of bacteria on plant seed surface by low-pressure RF plasma using a vibrating stirring device

Studies on applications of plasmas in agriculture have been conducted actively in many countries. The inactivation effect of low-pressure RF oxygen and air plasmas on seed-borne bacteria on plant seed surfaces was investigated. Active species generated in low-pressure plasmas could reach all seed surfaces using a vibrating stirring device, and the inactivation effect would be improved. When cabbage seeds contaminated artificially by Xanthomonas campestris pv. campestris (Xcc), one of seed-borne bacteria that have high pathogenicity, were irradiated by low-pressure oxygen and air plasmas, the inactivation effect with the vibrating stirring device was more than approximately 10 times higher than that without the device. Although the surface of cabbage seeds suffered the crack-like damage, germination rates of cabbage seeds at 3 and 7 days after seeding were not affected by low-pressure oxygen and air plasmas. Also, abnormal cotyledon and root on germinating cabbage were almost not observed after the seeds irradiated by low-pressure plasmas were cultivated for 7 days. Furthermore, occurrence of mold and rot on germinating cabbage was not observed when cabbage seeds were irradiated by low-pressure plasmas and cultivated for 7 days.