Research on diseases in potatoes was of great social importance in the first half of the twentieth century. For large parts of the population in the Western Hemisphere, and especially for the less affluent classes, the potato was the main source of food. Potato diseases could lead to famines, the most notorious of which occurred in Ireland, where an estimated one million people died between 1845 and 1850.

In leafroll disease, the upper leaves of the potato plant ‘roll up’ on themselves, preventing the plant from developing properly, and severely hampering the growth of the potato tuber. If a potato field was affected, it usually meant over half the crop would be lost.