SEATTLE, Washington — Coffee trade is the second-largest commodity market in the world, with production occurring largely in the area known as the ‘coffee belt’. Most of the countries located within the coffee belt are also developing countries, most of which have felt the pain of an epidemic known as la roya, or coffee leaf rust. From Sri Lanka to Colombia, the spread of coffee leaf rust has disrupted economies and endangered livelihoods.
Coffee leaf rust is a plant disease caused by hemileia vastatrix, a parasitic fungus which attacks the leaves of coffee trees, covering them in orange, yellow and red spots. The fungus drains the plant’s intake of nutrients until the tree’s leaves turn black and fall off and it dies. Because the plant needs four years to yield beans, coffee leaf rust is devastating to producers.
Coffee leaf rust flourishes in wet climates, particularly those with more than one rainy season or a temperature range of 59 to 82 degrees Fahrenheit. This is due to the way the fungus develops and germinates. The entire reproductive process takes around two weeks from initial infection to the production of new spores from the rust lesions, and the process is continuous during favorable weather. Due to rising global temperatures, this is projected to become an increasing problem for the coffee economy.
English explorers first reported the fungus in East Africa in 1861. One of the earliest victims of the fungus was the coffee economy of the island of Ceylon or Sri Lanka. By the 1970s (the exact year is disputed) the fungus spread to Brazil. Once it was reported, eradication and quarantine measures failed due to the ease with which the spores dispersed through the wind, leading to the proliferation of the disease throughout the Western Hemisphere.
A 2010 outbreak of coffee rust in Guatemala spread through 11 countries in Central and South America. More than 230,000 jobs were lost in El Salvador, Guatemala, Costa Rica, Nicaragua and Honduras, and regional production dropped 17.1 percent for the 2012-13 season. As of November 2016, Colombia, one of the biggest coffee producers, has since rebounded from the epidemic which cut its production in half.
The collapse of coffee farms in these areas has led to increased emigration and economic disruption. Large farms are often able to overcome an outbreak using various tactics to mitigate the damage while also keeping their prices competitive. Small farms, on the other hand, are often less able to recover without increasing their prices, which decreases their ability to compete. This multiplies the economic danger to small coffee farms.
Due to the impact of coffee leaf rust on the global economy, successful mitigation and prevention strategies are of vital importance to growers. Though some resistant strains of the coffee Robusta variety of coffee plant have been developed, the application of fungicide, such as BioNovelus’ non-toxic, biodegradable CR-10, is a common method used primarily on Arabica and sun-grown plants.
The use of fungicides cuts into revenues, however, which puts pressure on small farmers. It has even been noted that fungicides “can actually perpetuate the conditions that make coffee plants more susceptible to disease”, according to B Corporation Sustainable Harvest. As an alternative to fungicides, HunterLab offers that the use of spectral analysis instrumentation will allow farmers to spot infected plants by detecting their spectral signature, which is a numeric value keyed to the infected plant’s DNA.
Another method is using lower-yield shade-grown plants, which slow the fungus’ spread due to the presence of canopy-level trees and better plant nutrition. This is because sun-grown plants have a higher yield and require more nutrients, which leaves them more vulnerable to infection. This is comparable to humans getting more rest to stay healthy or combat a sickness.
Other coffee leaf rust solutions are more drastic, beyond that of which most farmers are capable. The most surefire method of ridding a farm of the disease is to destroy all coffee plants, wait multiple harvest seasons and plant anew. Another option is to move to higher altitudes. Without the luxury of this kind of flexibility, tens of thousands of farmers will be looking to central government efforts and enterprise to combat this epidemic before their livelihoods are destroyed.
– Lucas Woodling