[Remark: The RCAF wages war on the deadly wheat rust] Shots of Royal Canadian Air Force office at 797 Notre-Dame Avenue, Winnipeg, of two RCAF personnel in front of tent, of Dr Craigie of the Department of Agriculture. CU of Keystone Puffer biplane, Flying Officer Shields sitting in cockpit. Shots of sulphur dust being dumped into hopper of plane, of plane taking off. High AIR TO AIR SHOT of Puffer airborne. Very interesting shots of airplane hedge hopping, flying low over camera, sulphur dust trailing, plane pulling up abruptly. [Titles interspersed; End Title]