If your favorite coffees come from south of the border, you may be in trouble next year. The unusually wet rainy season and warmer average temperatures in Central America and the northern countries of South America have resulted in widespread coffee leaf rust, a parasitic fungus that attacks Arabica coffee trees and strips them of their leaves. With the leaves gone, coffee trees can’t kick up enough energy through photosynthesis to ripen coffee cherries. The end result could be devastating for the coffee industry this year.

 According to the International Coffee Organization, this year’s outbreak of coffee leaf rust is the worst one ever seen in the Americas, affecting as more than   50 percent of the 2013 crop. Guatemala and El Salvador, which have been producing some of the specialty coffee world’s most highly rated coffees lately, are especially hard hit. A May 2013 report shows that 74 percent of the Guatemalan crop and 70 percent of the El Salvadoran crop are affected. Costa Rica, Nicaragua and Honduras are also seriously affected. The loss in those Central American countries is expected to be about 2.7 million bags of coffee, with a value of about $500 million.

In addition to the monetary losses to the specialty coffee industry, the coffee leaf rust fungus is likely to wreak havoc socially and economically on the coffee-growing regions. The ICO report notes that the lack of coffee cherries to harvest could cost about 374,000 jobs in the countries affected.

Coffee Rust and the Environment

Coffee leaf rust has probably been around as long as there have been coffee trees, but the first real reports of it being an issue date back to Ceylon (now Sri Lanka) in the 1850s. The fungus eventually essentially wiped out the coffee industry on the island. It was officially detected in Africa in the 1870s, and by the 1960s, had spread throughout Indonesia. In the 1970s, coffee leaf rust appeared in Brazil, the first time it had been found in the Americas. Typically, the outbreaks are small, but the combination of higher than usual rainfall and temperatures have created the ideal environment for the development of the fungus that causes coffee leaf rust.

Other Factors in Coffee Leaf Rust Proliferation

Other factors may also be making this outbreak of coffee leaf rust worse than usual, including some factors that specialty coffee lovers support and prize highly. An article about the issue from the Specialty Coffee Association of America notes almost in passing that some experts believe that the shift to high-density monoculture – typical on coffee plantations in Central America – makes it easier for the fungus to spread. Another factor is the fact that organic fungicides – most typically copper sulfate – aren’t nearly as effective in combatting coffee leaf rust as a synthetic fungicide, Triaziline. Unfortunately, using Triaziline even once will cost a farm its organic certification. An article in The Atlantic last month questioned whether “well-intentioned” but uninformed consumers were contributing to the coffee rust problem with their insistence on organic coffee beans.

Meanwhile in Colombia

You might have noticed that Colombia was not on the list of coffee producers that are seriously affected. In fact, Colombia is the only country in Latin America with regions that have been declared completely free of coffee rust. Over the past several years, the national Federation of Coffee Growers, known as Fedecafe, and other coffee organizations and programs in the country, have engaged in a coffee renovation program, distributing rust resistant coffee plants to farmers across the country. As a result, Colombia’s coffee output in May was 36 percent higher than it was at the same time last year.

The Bottom Line

U.S. consumers aren’t likely to see the effects of this year’s coffee rust outbreak until next year, when this year’s harvest would hit the markets, if there was one. Things may not be as dire as they seem at the moment, but scientists and agriculturists don’t hold out a lot of hope. In fact, they’re strongly suggesting that we may be in for several years of lower coffee harvests than we’re used to seeing.