History of Phytophthora

The genus Phytophthora has played a significant role in both human history and the history of plant pathology. During the 1840s, an “unknown agent” caused epidemics of late blight in potatoes in the United States and Europe, culminating in the famous Irish Potato Famine of 1845. In Ireland, as a result of a combination of factors, the potato was the main source of nutrition for millions of people, and the crop losses led to the death of over a million people and caused another million to flee the country (The History Place). At this time, the cause of plant diseases like late blight was not known, and the origin of the disease remains a subject of debate (Abad & Abad, 1997). The severity of this blight prompted a few scientists to delve deeper into finding the cause, leading to the origins of plant pathology as a science. Reverend Miles Joseph Berkeley became the main supporter of the “fungal theory” of late blight (1845) based on his observations of mold-covered infected potato leaves under the microscope. In 1861, Heinrich Anton de Bary provided evidence that late blight was indeed caused by the "fungus." De Bary coined the name Phytophthora from the Greek phyton, “plant,” and phthora, “destruction:” the “plant destroyer.”