Potato virus Y (PVY) is the most serious problem facing the potato industry in the United States and is the main cause for rejection of seed potato lots. The virus affects potatoes in two ways: It reduces the yield of potato tubers by 70-80% and also negatively affects the quality of the remaining tubers due to necrotic reactions.
Click here for original story, Potato virus Y is the most serious threat to potato—some strains more than others
Source: Phys.org