These are required in small quantities by the plant, but they are still essential for plant health and production. The trace elements are Copper (Cu), Iron (Fe), Manganese (Mn), Molybdenum (Mo) and Zinc (Zn) and without them plants will exhibit a variety of deficiency symptoms. Copper sulfate is an inorganic compound that combines sulfur with copper. It can kill bacteria, algae, roots, plants, snails, and fungi. The toxicity of copper sulfate depends on the copper content. Copper is an essential mineral. It can be found in the environment, foods, and water.