How effective is mancozeb as a fungicide?

Mancozeb is more effective on crops in early stages of fungal infection, notes North Carolina State University. Mancozeb is a common fungicide that can shield crop seeds and fields from various types of fungal disease, according to Cornell University.

Mancozeb is effective against diseases such as rust, downy mildew and early potato blight, explains the University of Wisconsin. Users may need to combine mancozeb with other fungicides for certain crop types, suggests Ohio State University. Mancozeb is only effective when people apply it to crops externally, rather than adding it to the soil, notes Cornell University. Farmers and gardeners have been using mancozeb since the 1960s.