Fungicide, << FUHN juh syd, >> is a substance used to kill or retard the growth of fungi that are harmful to human beings, other animals, or plants. Diseases caused by fungi can destroy or seriously damage food crops. In the 1840’s, a fungal disease destroyed most of the potato crop in Ireland, where people depended heavily on potatoes for food. About 1 million people died from starvation during this disaster, called the Great Irish Famine. A fungus also caused the chestnut blight that killed most of the American chestnut trees in the United States during the early 1900’s.
Fungicides are used to protect plants and human beings from fungal diseases. Growers may spray or dust plants with fungicides to control fungal diseases called rusts, mildews, smuts, and molds. Fungicides also protect potatoes, apples, and other crops from diseases called blight and scab. Farmers treat many crop seeds with fungicide to prevent damping off, a disease that kills young plants. Fruit growers apply fungicides to many fruit crops, including peaches, grapes, and strawberries, to prevent rotting, a breakdown of plant tissue or other material caused by fungus.
Human beings use preparations containing a fungicide to prevent such diseases as athlete’s foot and ringworm. Fabrics used for tents and other outdoor purposes may be treated with a fungicide to prevent rotting. Many household cleaning products and some house paints contain a fungicide to prevent mildew.
People have used fungicides for many years. One of the oldest fungicides, powdered sulfur, became common in the late 1800’s. It is still used on grapes and other crops to help control mildews. Most fungicides used today are synthetic (artificially created) compounds. Chemical companies make them in laboratories and test them extensively for safety and effectiveness before selling them. In the United States, the Environmental Protection Agency (EPA) is responsible for making sure fungicide products are safe for people and the environment.
To be effective, fungicides must be poisonous to fungi. But they must not be harmful to the plants or animals they are supposed to protect. Fungicides must be used with care, because some can harm plants if they are applied too heavily. Some fungicides are poisonous to human beings and animals. Always store such chemicals where children, pets, and livestock cannot reach them. Wash fruits and vegetables treated with fungicides before eating them.
