Answer:
Smut:almost destroyed the entire U.S. corn crop in 1972
Step-by-step explanation:
Smut is a type of plant disease,caused by fungus Sporisorium scitamineum which has destroyed entire U.S corn crop in 1972.
In the initial stage infection caused by the smut is grayish-white and there is spongy growth called galls after that it gets ripen, and the galls change into black, then it gets burst.
This gets spread by the dispersed of winds that cause disease in the plant.
It results in the formation of blisters in the leaves, seeds, flowers, and stem.