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For many of us, a life without chocolate would be a very sad thing, but there’s more than our taste buds at stake. There’s a whole economy that depends on it.
“It” is actually the cocoa bean, without which M&Ms, Snickers bars, and hot fudge sundaes would not exist and millions of people would lose their livelihood. The bean is the fruit of the cacao tree (Theobroma cacao means "food of the gods"), which was domesticated by the Mayans 1500 years ago from its origins in the Amazon rain forest.
The tree, when domesticated, is about the size of an apple tree and thrives in hot, rainy climates around the equator. Four to five million farmers in Africa, Southeast Asia, and Central and South America grow the cacao tree. The cacao butter is also used in some soaps and cosmetics.
Unlike other more perishable crops, cocoa beans can be stored for months at a time, and people in developing countries can use them to buy food and clothing. Cocoa also protects the landscape: cacao trees grow better under shade and help to protect the biodiversity in the tropical regions of the world.
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Prakash Hebbar, Ph.D.
Hometown: Kerala, India
Education:
PhD, Plant Microbiology, Australian National University, 1986
Master's, Medical Microbiology, Mysore University (India), 1977
Bachelor's, Biology, Mysore University, 1973
Research Interests: Environmentally friendly methods to manage pests and diseases in crops and improving farmer livelihoods
Hobbies: Travel!
Last Book He Read: The Third Chimpanzee by Jared Diamond
Favorite Treat: Black Forest Cake with an additional layer of dark chocolate
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That’s the good news. The bad news is that every year, one-third of cocoa crops don’t survive. The trees succumb to many pests and diseases that destroy the fruit and consequently reduce the income of their growers.
The major diseases are caused by fungi, and they have quite strange names, such as witches' broom disease, frosty pod rot, and black pod. These names are based on what the disease does to the appearance of the cocoa pods or the tree branches. Certain insects (e.g., cocoa pod borer, cocoa mirids) also cause major problems for farmers in Asia and West Africa by boring into the fruit or chewing them.
That’s where Prakash Hebbar comes in. A microbiologist for Mars Inc. working in collaboration with the United States Department of Agriculture, Dr. Hebbar travels all over the world, working with scientists from the chocolate-producing countries and cocoa farmers to help them reduce pests and diseases and produce better crops using sustainable methods. “I talk to them directly or with in some cases through an interpreter,” he says. “We also work in the farmer field schools.”
In these schools, the farmers come and share their traditional knowledge and also receive training on how to improve their production. Usually, Dr. Hebbar says, these are villagers with strong leadership abilities who will take what they learn and share it with other farmers as a group. Dr. Hebbar and the other scientists literally go into the field with the farmers, who show them the problems with their crops, so learning is a two-way street between the growers and the scientists.
When Cogito talked to Dr. Hebbar, he had just returned from Cameroon, in West/Central Africa, where he was working with scientists and farmers to find ways to reduce the damage caused by the black pod fungus. This fungus is related to the one that caused the famous Irish potato blight in the 1840s.
Questions and Answers
Here are Dr. Hebbar's answers to your questions, submitted in June 2007.
Do you see the same sorts of fungi around the world? If not, why?
Fortunately the pathogenic fungi that have devastated the cocoa crop in South America (the witches' broom and frosty pod rot fungi) are not present in Africa or Asia. These pathogenic fungi seem to have co-evolved with the host plant cacao, which has its origins in the Amazon region. Recently the frosty pod rot pathogen has moved north into the cacao growing regions of Mexico and Belize and efforts are being made to see that it does not move into Africa or Asia. Only one fungus that infects cacao trees – the one that causes black pod disease – is present worldwide.
How is the fungus transmitted from one cocoa tree to another, and what advances have been made to control the various forms of the fungus?
The fungus moves from tree to tree via wind or rainfall splash. The spores are dust-like and have been shown to move via air currents. Long-distance transmission has often been performed by humans, unknowingly moving pods that look healthy.
The main emphasis has been on breeding for disease resistance, and cacao trees are now available that are tolerant to the disease. Farmers are being trained to re-plant and graft these new varieties. However, there is no magic bullet. The farmer has to keep his farm as clean as possible by either composting or burying diseased pods and must fertilize his plants and keep them well pruned. We are also at an early stage of testing certain co-evolved natural enemies of the pathogen, recently discovered in the Amazon region of Brazil.
What environmentally-friendly methods are used to stop pests? Are these as effective as the harmful ones, or do you see a need for improvement?
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Crinipellis perniciosa, the fungus that causes "Witches' Broom Disease." An infected crop may lose up to 90% of its harvest. (Source: Wikipedia)
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Very often in nature, every pest has a predator. Fungi have their own natural enemies, which reduce their ability to produce wind-borne spores. We are actively researching this area in the cocoa-growing countries so that there are alternatives to chemical products. There has been no breakthrough yet, but we have some promising results.
Insects are another problem, and a different approach to pest control is being tried with them. In Asia, the effectiveness of using insect sex-pheromones to attract the insect pests is being tested so that the farmers do not have to rely solely on chemical methods. There is no quick fix or magic bullet to solve these problems. It has to be an integrated approach.
What impact might climate change (e.g., changes in temperature and rainfall patterns) have on cacao plants and/or the pests that can damage them?
Cacao is a tropical rainforest crop grown mainly 10° to 15° north and south of the equator. It needs more than 1200-1500 mm of annual rainfall and has a temperature optimum of 25-30° C. If climate changes effects the quantity of rainfall, its patterns, and temperature, then cocoa crop will surely suffer. The crop cycle, which is flowering, pod set, and pod maturation, depends a lot on the environmental conditions.
Drier conditions may actually reduce fungal diseases, which thrive under humid and cooler conditions; however, insect damage is often greater in drier conditions. Diseases can be managed better if there is dry season that follows the long wet season. This gives the farmer a chance to clean his farm. However, if the rainfall is sporadic and frequent, the diseases are likely to increase.
Has there been any genetic modification of the cocoa plant?
Research programs to produce trees that are resistant to diseases and pests and that will yield larger crops for farmers rely on traditional plant breeding approaches. There are no genetically modified cocoa plants in the field.
The first Europeans to encounter cacao were Christopher Columbus and his crew in 1502, when they captured a canoe at Guanaja that contained a quantity of mysterious looking “almonds,” which they at first mistook for rabbit droppings.
The cargo was burned without any further knowledge gained about cacao.
- Source: Wikipedia
What processes are used to turn the cocoa bean into chocolate?
Once the cocoa pods are opened and the beans are taken out along with their pulp, they are fermented for 2-4 days in boxes or in heaps under banana leaves (traditional method). This brings out their unique chocolate flavor. This is followed by sun drying, roasting, removing shells and finally grinding to obtain the cocoa liquor. This can then be pressed to extract the cocoa butter and cocoa powder. Depending on what your final product is, from dark chocolate to milk chocolate, one needs to add varying quantities of cocoa liquor, cocoa powder, cocoa butter, milk powder and sugar. The lower the amount of sugar and milk, and the higher the amount of cocoa powder, the darker will be the chocolate.
What makes chocolate so irresistible to us?
Many things! In addition tasting so good, there is some thing mysterious, exotic, about it. Its taste and aroma are so complex. (Editor's note: Wikipedia has more to say about the allure of chocolate.)
Is chocolate good for you in some way? If so, which is better for you: dark or milk chocolate?
Recent research has shown that cocoa beans are rich in antioxidants called flavanols, which are beneficial for our cardiovascular health. These are often referred to as “phyto-nutrients.” If cocoa beans are processed carefully to preserve the flavanols, these compounds are present in higher concentrations in dark than in milk chocolate. The cocoa and milk in chocolate contribute small amounts of calcium, magnesium, and other essential nutrients to our diets.
How much nutrition is lost processing chocolate and, if we didn't process it as much as we do, would we truly benefit from it?
Traditional methods for making chocolate from the raw cocoa beans do not have a major impact on the mineral content of chocolate; however, they do impact the levels of certain compounds such as cocoa flavanols. Some modern methods allow cocoa to be processed to maintain both its quality and flavanol content.
In the wild, the cocoa pods do not naturally drop off the tree when they are fully ripe, nor do they break open to release the beans. Because of this, the cocoa tree is dependent on wild animals to break open the pods and scatter its seeds. ... and thus help guarantee another generation of cacao trees.
- Source: Amano Chocolate
I have read that a substance in chocolate can kill dogs. What is that substance, and why is it so dangerous to dogs?
Chocolate does not necessarily kill dogs. The compound that is toxic to dogs if consumed in large quantities is called theobromine and is present in small concentrations in chocolate. It is advisable not to feed dogs chocolates as they are unable to digest this compound, which is similar to caffeine.
What is the best part of your job?
There are many aspects of my job that are “the best.” I would say the top one would be the ability to meet people in various countries, especially the farmers who grow the crop, and to make a difference to their livelihoods by applying research findings. In addition, understanding a new culture and trying to learn a new language is always exciting.
Do you eat a lot of chocolate?
No, I do not eat a lot, but in moderation, especially after a good meal. I love to try new chocolate recipes, especially from new origins. My favorite chocolate, from Ecuador, has a fine fruity-floral flavor.
If you hadn't chosen to be a microbiologist and cocoa scientist, what would your profession have been?
A story teller or a writer for a travel magazine!
Further Reading