Bonide Copper Fungicide RTS (16oz)Bonide Captain Jacks Copper Fungicide RTS (16oz) is a ready to spray formula designed to protect your plants from a wide array of fungal diseases. It effectively treats and prevents blights, leaf spots, downy mildew, powdery mildew, and more across a variety of crops and ornamentals. Formulated with copper octanoate, a naturally derived compound, this fungicide creates a protective barrier on plant surfaces to halt the development of fungal pathogens.