1958 US–UK Mutual Defence Agreement as an atomic spy, caused the proposal to be dropped. The June 1951 defection of Donald Maclean, who had served as a British member of the Combined Policy Committee from January 1947 to August 1948, reinforced the Americans' distrust of British security arrangements. The first British atomic bomb was successfully tested in Operation Hurricane on 3 October 1952, but although it was more advanced than the American bombs of 1946, Britain was still several years behind in nuclear weapons technology. The United States conducted Ivy Mike, the first nuclear test of a true thermonuclear device (also known as a hydrogen
Atomic gardening and other growth abnormalities". Beyond these were the plants of interest, with a higher than usual range of mutations, though not to the damaging extent of those closer to the radiation source. These gamma gardens have continued to operate on largely the same designs as those conceived in the 1950s. Research into the potential benefits of atomic gardening has continued, most notably through a joint operation between the International Atomic Energy Agency and the U.N.'s Food and Agriculture Organization. Japan's Institute of Radiation Breeding is well-known for its modern-day usage of atomic gardening techniques. The popularity of atomic gardening coincided