Answer:
The crop failures were caused by late blight, a disease that destroys both the leaves and the edible roots, or tubers, of the potato plant.
Step-by-step explanation:
Great Famine, also called Irish Potato Famine, Great Irish Famine, or Famine of 1845–49, famine that occurred in Ireland in 1845–49 when the potato crop failed in successive years. The crop failures were caused by late blight, a disease that destroys both the leaves and the edible roots, or tubers, of the potato plant. The disease spread to Ireland from an airborne infection that was carried from ships travelling from America to Ireland.