The disease known as Potato blight triggered the great Irish famine. It also killed one million Irish people and at least as many Irish emigrated to the United States. But this disease didn’t start in Ireland, it first appeared the eastern United States, in early 1843. It didn’t show up in Ireland until 1845. It is said to be the first time a plant disease has changed the world. One reason potato blight was so widespread is due to a lack of genetic diversity. Back then everyone planted the exact same potato variety. Each potato was genetically identical to every other potato. When there is more genetic diversity, it is more difficult for plant diseases to spread.
Growing Home: Potato Blight
