Fungicide
Fungicide is a substance used to kill or stop the growth of mold and other fungi on plants or food.
Think of it this way
Bleach cleans mold off a kitchen cutting board. You spray it on the surface and the mold dies. Fungicide works the same way. It coats plants or surfaces so mold spores that land on them cannot grow.
Explaining fungicide by grade level
Mold can grow on fruit after you pick it. Some coatings help stop the mold from spreading. You can rub oil or other safe liquids on the fruit skin. This blocks the mold and keeps the fruit fresh longer.