Searching for the perfect pod

Bekele F.; Bidaisee G. and J. Bhola.

Edited by Dr. Marissa Moses and Dr. Lambert Motilal (Cocoa Research Centre, The UWI St. Augustine Campus) of a Paper presented at the International Fine Cocoa Innovation Centre Conference & Symposium, Trinidad and Tobago, March 23-24, 2015.

A fundamental understanding of the biology of the planting material, can allow one to successfully exploit its full potential.

Some of us have green thumbs.

Those lucky individuals somehow get plants to grow and blossom with vigour and beauty to the envy of all others. While there is some underlying genius involved in successful horticulture, a fundamental understanding of the biology of the planting material however, allows one to successfully exploit its full potential. So it is too for cacao, an understory tropical tree that originated in the Amazon basin and today, is the exclusive source of the raw material used in a multibillion dollar chocolate industry.

The best way to understand the cacao material would be to examine it in groups. The manufacturing sector traditionally recognises three sets of cacao ie. Criollo, Forastero and Trinitario. Criollo is found mainly in Central America, Forastero in Brazil, and Trinitarios are a group of natural hybrids of the Criollo and Forastero. Each of these three groups has its unique strengths for different markets. If we examine Trinitarios for instance, this group is the basis of fine or flavour cocoa for which the Caribbean region is renowned. Trinitario cacao therefore commands a significant premium with New York futures in 2015 at $2858.00 US/tonne (with potential of $5000 US/tonne).

Within the Trinitario group itself there is much variation, which researchers all over the world have devoted their lives to evaluating in large plant collections called germplasm or genebanks. The International Cocoa Genebank collection in Trinidad is one such collection containing many Trinitario variants from around the region (Figure 1). Like the enthusiastic horticulturalist who searches ceaselessly for the best tasting varieties or the most beautiful blooms, researchers curate this massive collection searching for the best features such as the Pod index. Pod index is defined as the number of pods required to produce 1 kg of dried cocoa beans, with the best pod index being less than 20.

Pod index is considered to be a trait of great economic interest to producers, and researchers at the Cocoa Research Centre have successfully identified Trinitario cultivars with desirable pod index values. These include plants from the Imperial College Selections, Grenada, Costa Rica, Dominica, Guadeloupe, Grenada, Martinique and Trinidad. The undisputed “king” of the collection, as so fondly dubbed by the researchers of the Centre, is still UF11, a variant with a pod index of 13.94 from Costa Rica.

As we continue to understand the genetic relationship between Trinitarios, it is expected that these promising variants will be used in future local and regional enhancement breeding programmes.

The International Cocoa Genebank Trinidad contains varieties from cocoa producing countries such as Ecuador

To read more about such studies we recommend

  1. Johnson, E., Bekele, F., Brown, S., Zhang, D., Meinhart, L. and Schnell, R. (2009). Population structure and genetic diversity of the Trinitario cacao (Theobroma cacao L.) from Trinidad and Tobago. Crop Science 49: 564–572.
  2. Johnson, E., Bekele, F. and Schnell, R. (2004). Field Guide to the ICS Clones of Trinidad. Serie Técnica Manual técnico No. 54. Tropical Agricultural Research and Higher Education Center, Turrialba, Costa Rica. 32pp. ISBN 9977-57-398-0.
  3. Susilo, A. W., Zhang, D., Lambert, A., MISCHKE, S., and MEINHARDT, L. W. (2011). Assessing genetic diversity in Java fine-flavor cocoa (Theobroma cacao L.) germplasm by using simple sequence repeat (SSR) markers. Tropical Agriculture and Development, 55(2), 84-92.