Blights and rots are a family of plant diseases that destroy a great many trees, fruits and vegetables every year. Some of these diseases, like some of the diseases people get, are caused by bacteria. Many other blights and rots are caused by certain types of plants called fungi. (You can read about bacteria and fungi in separate articles.) Blights and rots are harder to cure than diseases that make people sick. A blight, like the lire-blight of apples, cannot be cured. It can only be controlled.
A blight or rot is controlled by burning all the plants that have become infected with the disease. All the other plants that are growing nearby are sprayed with certain chemicals that can prevent the disease from spreading. A blight or rot can make the leaves of a plant turn yellow, or brown or black. A blight or rot will make flowers droop and die, shrivel up fruit, and cause roots and stems to soften and decay. The American brown rot is one of the worst diseases that attacks fruit orchards.
Every year this rot destroys hundreds of thousands of bushels of peaches, plums, cherries, and apricots. Millions of dollars have been spent by the United States government in order to find out how farmers can fight the different blights and rots. A blight of potatoes caused a great famine in Ireland a little more than a hundred years ago. The Irish people were starving then, and many of them left Ireland and came to America because this blight had ruined the potato crop. Another blight is the chestnut blight. This disease has destroyed almost all the chestnut trees in America