The control of diseases with fungicides is based on PREVENTION: plant surfaces must be completely covered with the fungicide … There are few non-copper-based fungicides with activity for bacteria (e.g. The U.S. government’s Environmental Protection Agency (EPA) routinely reviews fungicides and their safety. They recommended using a copper based fungicide for control of both early and late blight. Currently, in the U.S. there are no human toxicity concerns associated with tomatoes treated with copper … Most fungicides … Copper fungicides are important for managing diseases caused by bacteria and managing resistance developing to other fungicides being used that are at risk. Use it in your lawn care to control moss in an oak tree and algae in a lawn. Actigard). Bonide Liquid Copper Fungicide was purchased and applied to five varieties of tomatoes … Liquid Copper Fungicide is a broad-spectrum fungicide that controls diseases caused by bacteria and fungi. Long answer: Copper is one of the most commonly-used fungicides for treating tomatoes organically. Copper-based fungicides have become a staple against high-value crop losses caused by bacterial and fungal diseases. While considered irreplaceable by growers as a preventive disease-management tool, copper … After researching treatments for early and late blight, I found great data on the Cornell University's Ag department web page.