Coffee cultivation in Sri Lanka was abandoned because of the disease

The collapse of coffee cultivation in 19th-century Ceylon (Sri Lanka) was caused by coffee leaf rust (Hemileia vastatrix). The fungal disease, first noted there in the late 1860s, produced orange powdery lesions that defoliated trees and sapped plant vigour, precipitating a rapid decline in yields and prompting planters to abandon coffee and convert estates to tea. By the 1880s–1890s most coffee acreage had been lost and exports plunged, effectively ending the island’s coffee boom [2]. Commonly called Coffee Leaf Rust (CLR) and nicknamed 'Devastating Emily' by colonial observers, Hemileia vastatrix is therefore the disease responsible for the abandonment of coffee in Sri Lanka [1].

Sources

1. [1] https://www.bspp.org.uk/wp-content/uploads/2022/11/PP5-Coffee-leaf-rust-rdcd.pdf
2. [2] https://www.npr.org/sections/thesalt/2018/10/16/649155664/coffee-rust-threatens-latin-american-crop-150-years-ago-it-wiped-out-an-empire