A Fungus Among Us
By Andrea Peck
Most of us love our cup of Joe, but did you realize what a hot commodity it is? Financially speaking, coffee is the most prized agricultural product in international trade. Of course, it's not hard to stop and see the caffeine—it's literally brewing worldwide. Globally, coffee is a huge economic force that runs through the veins of every country and quickens the pulse of the citizens therein. Knowing the sheer power of the coffee bean, it's hard to believe that a business that serves over a billion cups of coffee per day could be thwarted by a fungus. But, make no mistake; a couple of lowly fungi continue to loiter amongst the coffee plant foliage, wreaking havoc for farmers and those who rely on the coffee industry for their livelihood.
Coffee rust is a disorder caused by a fungus. It is common to the coffee plant, particularly Coffea arabica (Arabica coffee) and coffea canephora (robust coffee). There are two pathogens. Hemileia vastatrix, is found worldwide, while H. coffeicola is primarily located in western and central Africa (the higher and cooler regions). Both fungi thrive in rainy weather—the drip, drop of water feeds the fungus, allowing it to proliferate. Wind helps to spread the pathogen to nearby and even faraway, leaves and plants. Latin America is perhaps the hardest hit; however, Central America, Colombia, Mexico, Peru and Ecuador also find themselves battling this pervasive disorder.
While farmer's toil in desperation, clipping overhanging branches, cutting down and replacing affected coffee plants, applying fungicide and fertilizing, researchers may have found a glimmer of hope in the convenient shape of a hole-punched circle. It seems that among fungi there are those who work in the name of Evil, and there are those who work for the Side-of-Good. This insight may provide a possible future solution.
Researchers decided to take a long look at fungi, which we all know takes a very patient and diligent person--so, bravo to them. Utilizing a simple hand-held paper punch, they took leaf samples from various coffee plants—some were infected with coffee rust, some were not. The samples, a ¼” diameter in size, showed remarkable diversity. Approximately 300 species of fungi were found in a sampling area, including about 15 types of fungal parasites that lived adjacent to or within the various fungi. Each coffee rust infected (hole-punched) leaf sample had up to 62 varieties of fungus, while the non-infected (hole-punched) samples had more— up to 69 varieties. But, it was the presence of the fungal parasites, called mycoparasites, that caught the researcher's attention. In particular, a well-known mycoparasite called white halo fungus which attacks insects, such as the coffee green bug and helps minimize coffee rust fungus.
It is possible that while taking a needed break at the watercooler, one researcher mentioned to another researcher how many fungi they had on their little hole-punched circle. This of course, led to fungi envy which Freud discusses extensively in his unpublished works. When the tiny, hygienic swords were laid to rest, the researchers may have seen the possible solution on the tip of their metaphorical noses. Could fungi fight fungi?
The answer, of course, is somewhere out in the future. Though the novelty of such a finding is ample reason to jump for joy, researchers caution that the practical use may present problems that require further study. Nevertheless, the discovery is eye-opening and one which could finally put the amped-up coffee rust disorder to bed.
I'll gladly drink a cup of coffee to that.