Effects of irradiation on corn. Plant seedlings grown from seed exposed to an atomic bomb, showing the effects of irradiation. The seeds were taken from a plant exposed to nuclear fallout from an atom bomb test in the Bikini Atoll, Marshall Islands. Bikini Atoll was the site of a number of above-ground nuclear weapons tests until the Nuclear Test Ban Treaty was signed in 1963. Photographed at the California Institute of Technology (Caltech), USA. Photographed circa 1949.