By Brandon Keim
June
11, 2013
A disease called coffee rust has reached
epidemic proportions in Central America, threatening the livelihoods of
hundreds of thousands of farmers and the morning pick-me-up of millions of
coffee drinkers.
Caused by a leaf-blighting fungus, possibly
exacerbated by growing practices and climate change, the disease leaves coffee
plants spindly and barren, their precious fruits unripened.
“Where people have been using heirloom
varietals for a century, you just have trees without leaves,” said David
Griswold, president of Sustainable
Harvest Coffee Importers. “We’re already into the flowering cycle now, then
it takes nine months to incubate the beans. You can see from the flowering what
the losses will be. It’s just twigs. It’s as though you’re walking through a
forest of twigs.”
The effects haven’t been felt yet among
coffee drinkers in developed countries, but history gives a sense of the
problem’s potential magnitude. England, that quintessentially tea-drinking
nation, only became so in the 19th century, after rust outbreaks destroyed
coffee plantations in Sri Lanka and shifted production to Indonesia. That’s why
coffee is sometimes called java.
Coffee rust first occurred in Central America
in the mid-1970s, but outbreaks didn’t reach industry-threatening levels. Now
they have. After the latest flowering season, rust afflicts more than 50
percent of growing areas in a belt stretching from Guatemala through Honduras,
El Salvador, Nicaragua, Costa Rica and Panama.
Regional production fell by 15 percent last
year, putting nearly 400,000 people out of work, and that’s just a taste of
what’s to come. The next harvest season begins in October, and according to the International Coffee Organization, crop
losses could hit 50 percent.
Coffee is grown elsewhere in the world, of
course, but growers in Central America — and in Jamaica, Colombia, Peru and
Mexico, where the disease has also spread — specialize in Arabica varieties,
which are used in high-quality coffees. Robusta varieties — which are mixed
with Arabicas in mass-market, low-cost coffees — resist the disease, but don’t
taste as good.
“It’s the better-quality coffees that are
going to get more expensive and harder to come by,” said Peter Giuliano of the Specialty Coffee Association of America.
“People will be reminded that coffee is special and delicate.”
Nobody knows precisely why the
outbreak reached such extraordinary levels this year, though several factors
are implicated. The most prominent is climate: In the past, environmental
conditions at high Central American altitudes were not especially conducive to
the fungus, which requires warm, humid air to thrive, said coffee rust
specialist Cathy Aime of Purdue University.
Since the mid-20th century, though, weather patterns in Central America and northern South America have
shifted. Average temperatures are warmer across the region, with extremes of
both heat and cold becoming more pronounced; so are extreme rainfall events.
Those changes are reflected in
coffee rust’s spread to unprecedentedly high altitudes, said Peter Baker, a
climate and commodities researcher at the nonprofit Center for Agricultural Bioscience
International. In Colombia, where coffee rust didn’t before reach higher
than 5,000 feet above sea level, it’s now showing up at 6,500 feet, he said.
The same trend is found across the region.
If climate change is evident across
decades, though, signals are less clear in the past several years, in the
immediate runup to the epidemic.
Last summer is thought to have been
especially warm and wet, said Aime, an anecdotal impression extended by
Giuliano to the last several summers. Yet climatologist Hugo Hidalgo of the University
of Costa Rica noted that as the region on average became warmer between 2009 and 2012, local
temperature trends varied widely, as did rainfall.
In short, the exact role of weather
variations and climate change in the rust’s epidemic severity this year is
uncertain, even if they’re clearly implicated in its general spread.
“There’s increasing evidence that
climate change is part of the problem. You find coffee rust striking much
farther up the valleys than it used to. There’s no other plausible
explanation,” Baker said. “But what happened last year, and why it was so
aggressive and widespread, we’re still a bit [perplexed]. And if we don’t
really know what caused it, it’s going to be hard to predict.”
Growing
practices may also compound the problem. Coffee evolved as a shade-dwelling
plant, and while some crops are planted under canopies of shade trees, many are
planted in open fields under direct sunlight, allowing for
high-density crop plantations. These can be more profitable to farmers, but are
also vulnerable to disease.
Direct sunlight raises crop-level
temperatures even more, accelerating the germination period of rust spores,
said Aime. Unusual temperature patterns also stress the plants, many of which
have been custom-bred to flourish in very specific microclimates.
Open-field growing practices, including
increased fungicide and pesticide use necessitated by the stressful conditions,
may also upset ecological relationships that typically protect shade-grown
coffee plants.
Ecologist and coffee specialist John
Vandermeer of the University of Michigan, who raises coffee at field stations
in Chiapas, Mexico, says that sun-grown fields lack another fungus, known as
white halo fungus, that protects plants against insects and pathogens,
including coffee rust.
“The integrity of this once-complicated
ecosystem has been slowly breaking down, which is what happens when you try to
grow coffee like corn,” Vandermeer said in a February press release. “This year it seems to
have hit a tipping point, where the various things that are antagonistic to the
[coffee rust] in a complex ecosystem have declined to the point where the
disease can escape from them and go crazy.”
Aime called the confluence of changing
climate and sun-grown coffee “a perfect storm for the rust to create
epidemic-size infections.”
Fighting coffee rust won’t be easy.
It can take years for afflicted plants to recover, so prevention is the best
strategy, and containment a necessary but limited option. In either case, the
tools available to farmers are inadequate.
Farmers can spray rust with
fungicides or, if they follow organic growing practices, with copper sulfate
solutions. The latter are less effective and cause more environmental damage
than the fungicides, said plant pathologist Steve Savage, who recently retired
from Colorado State University. Organic standards may actually backfire.
Applying the fungicides correctly
isn’t easy, though, and non-organic farmers have been hit hard by the disease.
Rust-resistant Arabicas are the ideal solution, and several industry-led
breeding programs are underway, but it generally takes between 5 and 10 years
to develop new varieties.
Many coffee farmers can’t afford to
wait that long, and the newly resistant Arabica strains have so far gained
hardiness at the expense of taste — an unfortunate tradeoff, especially for
farmers who specialize in high-quality blends.
Savage said breeding would go faster
if the coffee industry used transgenic techniques, which they’ve avoided for
fear of customer backlash. Giuliano countered that many other cutting-edge
methods, such as gene-pinpointing selection techniques, are being used.
Resistance is simply difficult to engineer by any means.
An even greater challenge, said
Giuliano, will be developing heat-resistant varieties, which are also difficult
to engineer. Even before the outbreak, warming was considered a dire threat to Central American coffees, and
the region is expected to become even hotter in coming decades.
Peter Baker warns of “peak coffee,”
a riff on the phrase “peak oil,” implying that cheap, accessible Arabicas could
soon run out. Alternative Arabica sources may exist, however. Many wild-growing
coffees in eastern Africa, where the plants evolved, have yet to be tested for
commercial possibilities.
Indeed, today’s varietals are
relatively homogeneous, descended from a literal handful of beans carried out
of Ethiopia centuries ago. “Something less than one percent of the total
genetic diversity of coffee exists outside Ethiopia,” Giuliano said. “What we
want to do, as an industry, is go back to Ethiopia, to the mother ship, and
find better varieties.”
That will take more years. In the
meantime, Central America’s coffee industry will struggle — and could
potentially fail — to survive, jeopardizing millions of livelihoods. The toll
will also be environmental, as biodiversity-rich coffee plantations are
replaced by ranches and resource-intensive crops.
As for coffee consumers, they’ll
find Arabicas replaced by Robustas on breakfast tables and office desks around
the world. Caffeine will still be there, but not so much taste.
“If things keep going in the
direction they’re going in, good-tasting coffee will be much harder to come
by,” said Giuliano. “Cheap, ubiquitous, good coffee is an artifact of the 20th
century.”