Diseases of the Cocoa Tree (Theobroma cacao)

Cacao Plantation

If the cacao (cacao and cocoa are used interchangeably) farmer does not have enough problems with deforestation, pollination, child labor and slavery and possible extinction of the cacao tree, he must also be concerned with five major diseases which threaten the world of the cacao tree.  The three most frequent forms of disease to strike the cacao tree are witches’ broom, black pod rot and frosty pod rot.  Every year almost 40 percent of cacao trees are destroyed because of disease.  Witches’ Broom infects and destroys the entire cacao tree by allowing the formation of very small spore producing mushrooms.

Cocoa Pod with Witches' Broom Disease

It spreads quickly to the pods and its seeds when the weather is rainy and humid, aka the rainforest.  Between 1980 and 1998, more than 75 percent of the Brazilian’s cacao trees were destroyed due to human induced problem.  During this time, the production of cocoa beans dropped by 600,000 metric tons.  The amazing coincidence is that Witches’ Broom is only a problem for cacao tree plantations.  Cacao trees naturally present in the rainforests throughout the world are not susceptible to Witches’ Broom fungus. Approximately 25 percent of all cacao trees are killed annually due to witches’ broom disease.

Frosty Pod Rot Disease

Costa Rica saw the loss of over 73 percent of their cacao trees from Frosty Pod Rot in the 1980s.  This disease has surfaced in Nicaragua, Panama, Costa Rica, and Ecuador.  The disease attacks the pods by penetrating their surfaces.  The final result is swelling, change of color and white lesions on the pods.  There is currently research being conducted in Panama, Peru, and Costa Rica to eradicate this disease.  Researches seem to be having some success.

Black Pod Rot Disease

Black Pod Rot is another common disease among the cacao trees, and the disease with the most impact, causing the loss of 30-90 percent of the trees annually.  This is the worst of all of the diseases as it is a fungus that can grow on any cacao tree anywhere in the world.  It shows no mercy and attacks all parts of the tree.  When Black Pod Rot reaches the pods, lesions are apparent over the entire pod.  It then turns black and looks as if has gone through mummification.  Oftentimes the pods can be harvested before the Black Pod Rot reaches the seeds.  If the disease has penetrated the pod, the seeds will dry up and change color.  Black Pod Rot destroyed the Costa Rican cacao economy in the 1980s and has been severe in the past in both Western and Central Africa.  If Frosty Pod Rot or Witches’ Broom hit cacao production in West Africa, where over 70 percent of all production occurs, it would completely devastate the market.

Theobroma Cacao - The Tree of Change

There are currently pesticides that can be of some benefit to the cacao tree, however they are dangerous for the health of humans and animals.  There is a pesticide called Lindane sprayed on commercial African cacao trees that has been linked to breast cancer.  The Austrians conducted a study stating that Lindane is toxic and not safe at any level.  The European Union banned the use of this pesticide due to its risks and is being phased out, although many cacao farmers continue to use it.

Healthy Cocoa Pod

Theses diseases infected the cacao trees are difficult to control.  John Bowers, a plant pathologist with the UDSA ARS in  Beltsville, Maryland states, “A complicating factor in fighting disease is that many of the treatments that work in other situation 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.”  There are possible solutions in the future, but those are a long way off.  Plant pathologists are developing disease resistant breeds of the cacao tree and learning ways to stop the disease once it attacks a tree prevent the spread of the disease to other trees.  Europe has strict regulations to produce chocolate without the use of chemicals or pesticides during the cacao tree’s growing process resulting in organic chocolate.  Organic chocolate is becoming more and more popular among chocolatiers due to the concern of the environment and toxicity.  Although previously not considered to be of high quality, organic chocolate is moving into a realm of its own and becoming more popular among chocolate connoisseurs.

Cocoa Pod Borer Damage

There is a an insect called the Cocoa Pod Borer or Cocoa Moth that causes much damage to the pods of the trees but laying its eggs on the pods and the hatched larvae eat off the pods.  In 1998, the Cocoa Pod Borer caused the loss of 20 percent of the cacao tree crop for that season.  In order for these diseases and insects to be eradicated, governments, the cacao farmers and the chocolate industry must work together for the health of the cacao tree and the environment which it lives.  There needs to be a common ground between balancing the cacao tree’s environmental and economic value.  It is of utmost importance that the government works with the small farmers especially in supporting a sustainable and profitable cacao trade.

Sustainable Perrennial Cocoa Pod Crop

The best answer to the problems involving the cacao tree is to resort to the way nature intended the cacao to grow.  This will enable cacao farmers to control a more consistently profitable cocoa production.  There are other trees that can be grown above cacao trees that also have commercial value and all of the types of trees prosper.  Among the possible varieties are banana, rubber, grumixana, sapote, and breadfruit.  Sustainable cocoa growing protects the farmers allowing them lower production costs, guarantees a consistent income and allows enough cocoa for the world market.  Sustainable growing also protects the environment in that it minimizes the impact on the tropical rainforests of the world.  It relies on natural and traditional methods for farming which are not only less expensive, but better for the farmers, the earth and the cacao tree.  The result is a happy and well-balanced ecosystem allowing the original habitats and biodiversity among the rainforest.

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2 thoughts on “Diseases of the Cocoa Tree (Theobroma cacao)”

  1. Its very interesting to learn about the difficulties of cacao growers during the process in protecting the pods from the diseases before harvesting.

  2. I’m a enginer who lives to production of cocoa in a little town of Colombia and sometimes internet it’s the unique tool that I have. You have one of the most detailed articles that I have read, congratulations, many pages trait to do it, but even especialiced ones have failed, I really enjoy it your’s. Onces again CONGRATULATIONS (Sorry for my english)

    Oscar Portela

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