Origin of aerial application and early development. Development of an aerial application industry. Growth patterns and world levels of aerial application. Aerial application organizations. Government regulation of aerial application. Aerial applicator organizations. Government regulation of aerial application. Aircraft types used for aerial applications. Aerial equipment for despersing dry and liquid materials. Application techniques. Meteorological factors relating to aircraft applications. Operational analysis of agricultural aircraft use. Flight planning, aircraft lloading, and field layout. Aircraft flight safety and airworthines. Agricultural pilot training. Specific treatment practices.