Making sure there's enough chocolate in the world may seem like a sweet-heart of a job. But it's actually becoming quite a challenge. Five major diseases now threaten the world's population of cacao trees, from which chocolate is derived. But scientists working on the problem are optimistic that their efforts to control these diseases and create sustainable growing practices will work.
Once a substantial business, cocoa bean production in Brazil is now only one-fourth of what it was ten years ago, for the most part due to the invasion of a single fungus, Crinipellis perniciosa. In West and Central Africa where much of the world's cocoa beans are grown, losses due to another disease, black pod, range from 30 to 90% annually. Add to that the fact that black pod, like many of these diseases, has features that make it difficult to control, and you begin to understand why plant pathologists feel particularly challenged.
States John Bowers, a plant pathologist with USDA ARS in Beltsville, MD, "A complicating factor in fighting these diseases is that many of the treatments that work in other situations don't work with the cacao tree. Producing cocoa beans is very labor and equipment intensive so many of the disease management options we would normally use are either cost-prohibitive or too time-consuming to develop."
Since long-term solutions such as breeding for disease resistance or biotechnological approaches are not yet readily available, scientists have been employing the tools they do have. They're working with an international group of collaborators and growers to help them develop practices that discourage the development of disease and help prevent its spread if it does occur. Their overall objective is to work towards a sustainable cacao management system that fits within the diverse rain forest ecosystem. The strategies being investigated include biological control, induced disease resistance, crop sanitation, cultural practices, and limited use of pesticides. The challenge is to integrate all these components into a management strategy that inhibits disease development, and at the same time preserves and protects these valuable tropical ecosystems.
Right now scientists hope to keep these diseases in check while they work on developing more long-range controls. "No doubt it will be a combination of practices and new discoveries that will ultimately help us retain the health of the world's cacao trees," says Bowers. "We just need more time."
The American Phytopathological Society (APS) has a feature story on Diseases impacting world chocolate production.