Blight is a condition of diseased plants in which whole parts of the plant die and wilt but do not rot or fall off. The parts affected may be leaves, flowers, fruits, or even entire stems. The term blight is also used for a variety of diseases that involve these symptoms. Most blights are caused by fungi. However, fire blight, which attacks pear and apple trees, is caused by bacteria. Blights often are named for the particular plant part attacked. For example, blossom blight attacks the blossoms of cherry trees.
Blights can be very destructive. During the 1840’s, a potato blight in Ireland, where people were heavily dependent on potatoes for food, caused the crop to fail. About a million people died from starvation or disease during the famine. Blight can be avoided by using plants that have been specially bred to be resistant to disease. Spraying plants and disinfecting the seeds before planting can help prevent blight. As soon as a gardener notices diseased parts of a plant, those parts should be cut away and burned.
