The ergot-kernel was the only source for all ergot medicines and had to be grown on rye plants in an extremely labor-intensive process. The spore infection of each individual rye flower and the harvesting of the sclerotia were based on arduous manual work (Figs. 9.1–9.3). In the 1940s, cultivation of the Claviceps fungus, for which wild isolates were initially used, yielded around 880 pounds of ergot on 2.5 acres from which only 8.8 pounds of total alkaloids were obtained [1]. In addition to low-yield alkaloid production, there were also unpredictable and disruptive factors that could negatively impact the ergot harvest and jeopardize a stable supply to the pharmaceutical market. At the same time, demand for sclerotia continued to rise, further exacerbating the supply situation. Annual sclerotia imports to the United States alone doubled from 58 to 112 tons between 1913 and 1919, reaching a value of US$ 208,000 [2].