Extension Communications
3614 Administrative Services Building
Ames, Iowa 50011-3614
(515) 294-9915
11/4/02
Contacts:
Barbara Ambruzs, Plant Pathology, (515) 294-0581, ambruzsb@iastate.edu
Jean McGuire, Continuing Education and Communication Services, (515) 294-7033,
jmcguire@iastate.edu
Yard and Garden Column for Week beginning Nov. 8
Coffee Talk
By Barbara Ambruzs
Extension plant pathologist
Iowa State University
I don’t know about you, but I’m quite a coffee drinker. While sipping this rich brew, I usually don’t think about how a single plant disease impacted the history of such a huge industry.
This story begins with the origin of the coffee plant growing in the understory of Ethiopian mountain forests. The first use for the berries, which are the beans we grind to make the beverage, was for food. Ripe berries were squashed, combined with animal fats and shaped into balls or cakes, which could be carried and eaten on long journeys. Early drinks were probably used in religious ceremonies or as medicine.
By the early 1500s, coffeehouses were becoming popular in Egypt, Arabia and Turkey. Travelers from Holland who visited these exotic places saw the potential for coffee as a lucrative agricultural crop. Dutch colonists in Sumatra, Java and Ceylon immediately began planting coffee. Soon, the Dutch soon became major coffee suppliers to coffeehouses that were springing up throughout Europe. Of the three colonies, Ceylon grew to become the largest and most important coffee growing area in the world.
During the mid 1800s, Ceylon came under British rule. British colonists in Ceylon stripped the remaining forested areas and replaced them with coffee plantations. By 1870, Ceylon coffee exports reached about 100 million pounds of coffee each year, with most of it going to England.
Unfortunately for the British, Ceylon growers in noticed sick coffee plants in 1867. Orange-yellow spots appeared on the lower side of leaves. The spots were small, but became so numerous that they could cover the entire leaf bottom. Leaves fell off early and yield and quality were seriously reduced. After repetitive years of the disease, the plants died. Eventually, this leaf problem was identified as coffee rust, caused by Hemileia vastatrix, a fungus that has its origin in Ethiopia.
We may never know how the rust traveled to Ceylon. People thought the disease would go away on its own, but a year later it was obvious that it wouldn’t. Since the entire Ceylon area was planted to only one type of crop (monoculture), the coffee rust fungus easily spread from plant to plant and seriously impacted the region’s economy. The effects rippled throughout the world.
OK you tea drinkers, this part’s for you. Britain decided to plant the diseased areas to tea! Even though Anna Duchess of Bedford introduced afternoon tea in 1840, coffee was still the most popular drink until coffee rust hit.
The rust eventually spread to Sumatra and Java, so coffee production moved to South America, where Brazil became the leader in coffee production. It wasn’t until 1970 that coffee rust appeared in South America. Today, Hawaii is the only coffee rust-free growing area in the world.
Even with modern methods, control of coffee rust is still difficult. However, there are several ways the disease can be adequately managed. Most growers use fungicides, especially during the rainy season, because the fungus prefers moist environments. Pruning to improve air circulation, site selection for promoting vigorous plant growth and resistant varieties all help with disease management. However, the coffee rust fungus continually evolves in order to survive, and so the battle continues.
Today I finish my morning cup of Java remembering that the tiny beans used to fill my mug made quite a journey. They survived disease, adverse weather, and were plucked from shrubs growing in the mountains of far off places. Thanks to the growers and researchers who work to stay ahead of serious disease outbreaks in coffee growing regions, our cups remain full.
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ml: isugarden
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