Abstract
1) The irradiatation of potato tubers of var. May Queen affected with leaf roll disease by short (wave-length: 30.0m.) and ultra-short radio waves (wave-lengths: 8.9m, 36.0cm and 9.8cm) had no effect upon the virus involved.
2) The treatment of the potato tubers of var. Irish Cobbler affected with crinkle mosaic disease by short (wave-length: 30.0m) and ultra-short radio waves (wave-lengths: 8.9m., 36.0cm. and 9.8cm.) did not inactivate the virus.
3) The irradiation of the potato Y-virus in tobacco plant juice by ultra-short radio waves (wavelengths: 8.9m, 36.0cm and 9.8cm) had no lethal effect upon the virus so far as the temperature of the juice did not reach the inactivation point.