In the late stages of World War II, Japan employed thousands of incendiary and antipersonnel weapons via unmanned balloon, using some 9,300 of these devices, releasing them into the high altitude jet stream to travel over the Pacific Ocean to the North American mainland.
[2] The E77 was designated a "strategic weapon" and readied for deployment but was never used in warfare as subsequent developments in munitions supplanted the E77,[1][2] especially the 750-pound E86 cluster bomb.
[1] This dissemination method combined a culture of anti-crop agent with a light-weight vector, in this case, feathers.
From October to December 1954 41 E77s were launched at Vernalis, California, which demonstrated that the munition met "military characteristics" to create high levels of plant infection on targeted crops.
Subsequent investigations at Fort Detrick and the University of Minnesota came to several positive conclusions about the effectiveness of oils as carriers of the rust spores.