Parmentier’s promotion of potatoes effectively contributed to the spread of potatoes throughout Europe. One important caveat, however, is that the method he employed, which used pieces of previous potatoes to grow additional ones (instead of planting from seeds), reduced genetic diversity.[9] This meant that potatoes in Europe lacked a gene pool that could effectively reduce the spread of blight and disease. As a result, potato crops were vulnerable to outbreaks that contaminated the fields. Originating in Belgium in 1844 and spreading across the continent over the following several years, the potato blight wreaked havoc throughout the continent.[10] In Ireland, where crop failure combined with poor living conditions derived from the British conquest of Ireland in the mid-seventeenth, the potato blight had devastating consequences. Since the potato had become the most important staple of the Irish diet (in part because it was one of the few crops that grew in the poor soils of the island), the blight that spread across Europe wiped out nearly 88% of the Irish potato crop after it reached the island in late summer 1845.[11] Throughout the next several years, further disease and poor harvests ravaged the country, having the greatest impact on the poor who relied on potatoes as a cheap and easily growable crop. Mass exodus of Irish men and women, who left for the U.S. and Canada, was one of the key outcomes of Ireland’s potato blight.

Finally, potatoes played a crucial role in the development of other commodities and industries. As a crop, potatoes benefited greatly from improvements in agricultural development. The first major supporting commodity was that of guano. From the Chincha Islands, Peruvian guano became a major factor that allowed potato cultivation to rapidly expand to the degree that it did.[12] Enriching the soil with nutrients allowed for increased prosperity, driving the population growth of the eighteenth and nineteenth centuries. Additionally, potato cultivation also drove the rise of the pesticide industry. Beginning in the 1860’s, the potato beetle became a scourge for farmers growing potatoes across the United States. In experimenting with repelling these beetles, green paint, given its color through arsenic and copper, was found to repel the pests. From this discovery, isolated compounds of arsenic and copper sulfate gave rise to the pesticide industry that revolutionized mass crop production.[13]

Therefore, potatoes represent an agricultural product from the New World that revolutionized the world. After getting through the initial hesitancy to embrace the crop, mainly due to Iberian dominance across Europe, potatoes became a staple crop that was a major factor in Europe’s rising population. The effect of the potato blight in Europe, especially in Ireland, highlights the great depth to which potatoes were ingrained in its culture and drove patterns of migration in its absence. Potato’s rise in the United States, as an import from Ireland, marked its return to its native continent, highlighting its status as an Atlantic commodity that crossed the ocean first traveling east and then sailing back to the Americas. By the time it became a staple in the United States, the originally Andean potato was well on its way to becoming the global commodity that it has for a long time been.