Cacao farmer Gildardo Ramirez removes a withering pod from one of his trees. He suspects the pod is infected with black pod rot. (Credit: Lindzi Wessel)
With a machete, Gildardo Ramirez lops twelve pods off one of his cacao trees, letting them fall to its base. The long, brown pods look like twisted and deflated footballs. Each cacao pod usually encases about 40 beans — the source of cocoa powder and chocolate. The beans are the main commodity that Ramirez produces on his farm in San Francisco, Colombia, some 70 miles southeast of the city of Medellín. On Ramirez’s land, cacao’s red and green leaves fill the sloping hillside, overlooked by lush green mountains. But these twelve pods will never make chocolate. The healthy white, sweet pulp that normally encases the beans has turned dank and discolored. The pods are diseased — infected, he suspects, with a mold-like attacker called black pod rot. It’s just one of many threats that plague the region’s chocolate farms. For Ramirez, who works with Colombia’s newly energized tourism industry to teach visitors about growing cacao, it’s a heavy workload to keep such diseases at bay. At least three pathogens frequent his farm, and each requires dedicated management. When it comes to black pod rot and the similar frosty pod — a fungus whose spores turn a pod’s surface velvety white — removing infected pods early can help prevent the spread of disease. Pods infected by another fungus, called mal de machete, stay on the tree, but require treatment with a blue fungicidal paste. Even with his diligent attention, Ramirez guesses that these diseases destroy a quarter of his annual crop. Worldwide, 30 percent or more of cacao crops is lost to diseases each year, a persistent threat for the world’s $100-billion chocolate industry and a source of insecurity for the 40 million to 50 million people whose livelihoods depend on cacao. As Ramirez has found, any effort to boost cacao production means confronting the pathogens that so often afflict it. But much remains unknown about the diseases that target cacao. At least in Colombia, work to breed more resistant varietals or to study how cacao plants in the wild fend off pathogens has been limited. Now, as Colombia embraces a newfound stability after years of civil war, cacao science is getting a much-needed reboot. Native to Colombia and its neighbors, cacao (scientific name Theobroma cacao) has long played a role in the country’s history and culture. Unlike most other countries that grow cacao, Colombia’s production has mostly been aimed at meeting demands within its own borders — not so much for chocolate bars, but for traditional drinking chocolate. But as worldwide demand for chocolate grows, some see an opportunity to help Colombia’s farmers by increasing cacao exports. Over the last decade, Colombia’s farmers have gradually upped their cacao production. In 2016, it reached a longtime high of almost 57,000 metric tons. But that’s still short of 1991 levels (58,000 metric tons), the peak of Colombian cacao production. An overall decline followed, in parallel with growing civil unrest and other challenges. Decades of internal conflict, fueled in part by the illicit cocaine industry, wreaked havoc on the nation. But recent changes, including a peace treaty signed with the rebel group FARC in 2016, have brought a chance to rebuild. The government and its allies are eager to eradicate the many farms that still grow coca, the source of cocaine, once and for all. Since cacao and coca thrive in similar conditions, cacao has been promoted as one ideal replacement crop. Programs such as Cacao for Peace, which is backed by the US Agency for International Development, aim to help farmers make the shift. By focusing on making cacao farming more efficient, scientists may also be able to help. For scientists, the newfound peace offers opportunity for discovery, with regions long too dangerous to explore opening again to study. Now, researchers from both inside the country and abroad are ramping up sampling of cacao and its diseases from farms and wilderness areas. With visits to remote, largely unstudied areas scientists hope to find untapped strains of cacao that may hold the keys to protect chocolate farms from some of their most damaging enemies.
