Coffee Rust

Hemileia vastatrix, commonly known as coffee rust, is a fungal pathogen that produces orange, rust-colored powdery lesions on the underside of coffee plant leaves, eventually causing widespread leaf loss and reduced yields. It devastated the coffee industry of British Ceylon, now Sri Lanka, in the latter half of the nineteenth century, a collapse that led growers there to switch to tea production instead, and it remains one of the most economically damaging diseases threatening coffee cultivation worldwide today.