Coffee is the only known host of the fungus Hemileia vastatrix, which causes coffee rust also known as “roya”. The disease damages coffee leaves by causing the premature drop of infected leaves, which can lower yields by 50%.Coffee rust has become a greater problem for coffee growers because of climate change. Higher temperatures and increased rainfall favors rapid development of the disease.
“Costa Rica on Tuesday declared an emergency to tackle the spread of a coffee fungus that has already devastated Central American producers and looks set to destroy about 12 percent of Costa Rica’s planted coffee in the upcoming 2013/14 harvest.
A two-year emergency bill, signed jointly by Costa Rica’s Vice President Luis Liberman and the national coffee institute ICAFE, provisions about $4 million to pay for fungicides to tackle the roya, or leaf rust, outbreak.
Roya kills coffee leaves by sapping them of nutrients and lowering bean yields. The current roya pandemic has already affected other countries in Central America and Mexico, home to more than a fifth of the world’s Arabica coffee production.”
Author: Cota, I.
Affiliation: Reporter, Reuters.
Title: Costa Rica declares national emergency to tackle coffee fungus.
Source: Reuters. January 22, 2013.
In England in the early and mid-1800s, the most popular drink was coffee from plantations in Ceylon (Sri Lanka). When the coffee rust fungus destroyed Ceylon’s coffee trees in 1875, the plantations began growing tea.
“When the coffee rust fungus, Hemileia vastatrix, reached Ceylon in 1875, nearly 400,000 acres of the island were covered with coffee trees. No effective chemical fungicide was available to protect the foliage, so the fungus was able to colonize the leaves until nearly all the trees had been defoliated. … In 1870, Ceylon exported 100 million pounds of coffee. By 1889, production was down to 5 million pounds. In less than 20 years, many coffee plantations had been destroyed, and production had essentially ceased.”
“As the coffee trees were dying, however, the plantation owners noticed that the thousand or so acres of tea bushes were still healthy. …the owners replaced most of the dead coffee trees with tea bushes. By 1875, more than 1 billion tea seedlings had been planted on 300,000 acres—an amazing increase from the acreage planted only a few years earlier. … Luckily, no fungus invaded the tea crop immediately, and newly discovered fungicides were soon available to protect tea from its fungal pathogens.”
Authors: G.L. Shumann and C.J. D’Arcy
Publication: Hungry Planet: Stories of Plant Diseases. 2012. APS Press.
Coffee leaf rust is considered one of the most catastrophic plant diseases of all time. In the 1860s, coffee rust was largely responsible for destroying the coffee plantations of Ceylon (Sri Lanka), which had been the greatest coffee-producing country in the world. As coffee rust spread through Asia and Africa, coffee production increased significantly in Latin America where coffee rust was not present. However, coffee rust was detected in Brazil in 1970 and has since spread throughout Latin America, making fungicide use essential.
“In susceptible cultivars, chemical control has been the only option for decreasing the incidence of CLR on plants, and for reducing the harmful effects on the disease. The coffee growing regions in Brazil as well as almost all other coffee-producing regions worldwide are comprised of susceptible Coffea arabica and Coffea canephora cultivars (the latter is the second most widely cultivated coffee species). Preventive control of CLR in the main Brazilian coffee-producing regions consists from four to six applications of protective copper-based fungicides and two to three foliar applications of systemic fungicides.”
Authors: A. Fernando de Souza, L. Zambolim, V. Cintra de Jesus Jr., P.R. Cecon.
Affiliation: Federal University of Vicosa, Minas Gerais State, Brazil
Title: Chemical approaches to manage coffee leaf rust in drip irrigated trees
Publication: Australasian Plant Pathology. 2011. 40:293-300.