Two mind-sets manage risk better than one: Clean harvest in Colombia
Jeff Bentley and Peter Baker
Like coffee itself, the coffee berry borer (Hypothenemus hampei) is native to Africa, but its arrival in the Americas in 1988 put a multi-million dollar crop at risk. Colombia was especially hard hit. As entomologists studied borers’ natural history, they learned that this tiny beetle has no alternative host: it has nowhere to live but in coffee. It lives for most of its lifecycle inside the coffee berry itself. (image, coffee bean damaged by CBB)
Entomologists found that the borer had few natural enemies. Ants ate a few borers, but mainly the little beetles were free to eat all the coffee they wanted.
Colombian coffee growers were desperate. The borer was affecting most of the coffee growing area and was the Colombian Coffee Growers’ Federation was searing for an environmentally-friendly alternative. The individual farmers themselves were quite ready to use insecticide, but the researchers at Cenicafé (National Coffee Research Center), which belongs to the Federation, feared that the widespread use of pesticides would damage Colombia’s treasured reputation as the leader in high-quality, mild arabicas.
Researchers experimented with a fungus called Beauveria bassiana, but the farmers found it difficult to work with. Beauveria is an insect-killing pathogen which is harmless to humans. It could be reared out in rum bottles filled with cooked rice. Cenicafé encouraged the extensionists of the Federation to teach farmers to grow Beauveria, mix it with water and spray it on coffee trees. The farmers tried the Beauveria, but soon gave it up. It was hard to keep a farm kitchen in lab-like sterile conditions, difficult to find enough rum bottles and the Beauveria didn’t kill as many borers as insecticide did.
Meanwhile, entomologists had brought three species of parasitic wasps from Africa (1995-1999). The wasps lay their eggs in the borer, which dies. Once the wasps were released in Colombia they were able to live on their own, in the coffee groves. Unfortunately, one species adapted to Colombia with difficulty, and the other two not at all (Benavides et al. 2012).
The entomologists went back to their studies of natural history. If the borer only lives in coffee fruits, then farmers could rid eliminate the borer by cleaning up its habitat. So Cenicafé recommended a new practice which they called Re-Re (recollection and review): i.e. collect all of the ripe and over-ripe fruits from the tree and the ground.
Nobody liked the idea. The scientists found it an unsatisfying, low technology. For the farmers it was just too much work climbing around the steep, wet, slippery hillsides to pick rotten berries off the ground.
But the farmers improved Re-Re; they wouldn’t pick berries off the ground, but they would pick them off the tree. Unlike most of the tropical Americas, which have a marked dry season, rain falls throughout the year in Colombia. Rain triggers coffee plants to flower, and then to fruit, so there are coffee berries on the bushes year round in Colombia.
If the coffee growers went into the groves every two weeks or so, and picked the coffee as it ripened, this meant that there were fewer berries to fall on the ground. And unlike spoiled berries from the ground, berries picked from trees could be sold. Colombia farmers, especially women, had often harvested the off-season berries to earn pocket money during the year.
Clean harvest is now widespread, and is recommended by the Federation (Aristizábal et al. 2006). Now the men and women began harvesting more often, and more thoroughly. This controlled the borer reasonably well when wet conditions favor rapid rotting of fallen berries, although frequent small harvests are much more attractive when coffee prices are high (as they are now).
Researchers recommended a risk-management technique (Re-Re) which farmers adapted (as clean harvest) to make it more profitable.
Risk management depends on scientific understanding of background information. In this case, it took scientists realizing that the coffee berry borer had nowhere else to live, just coffee. And the farmers had their role to play in adapting the risk management strategies. No one can know everything. The farmers are generalists and the researchers are specialists who can home in on one specific topic and learn things about it that farmers would not discover. But because farmers understand how the whole farming system works they can then take the new ideas from scientists and adapt them to fit better in practical situations.