The reason cacao and our other crops are so vulnerable to disease is that we tend to grow a few high-yielding varieties that are genetically identical – in the case of cacao most trees in the world are clones of a few high-yielding trees selected in the 1940s, spread by cuttings. Fortunately for us there are still wild cacao trees and also many surviving older varieties that can be used to breed new trees. Which is what they are doing at Costa Rica's Cacao Genetic Improvement Program, which raises 1,235 different types of cacao tree:
In the early 1980s, Dr. Phillips-Mora worked to identify the most naturally tolerant and productive cacao trees, then painstakingly hybridized the candidates to create novel varieties.Not only that, but the chocolate tastes good. So while there is always a danger that a fast-spreading disease might devastate one of our major global crops, we are also very clever about breeding or engineering resistant strains.
Breeding hybrid cacao clones is a lengthy process, and experts worldwide have largely failed in this endeavor. But in 2006, Dr. Phillips-Mora released his first batch of hybrid cacao varieties.
In terms of disease resistance and yield, the differences were astonishing. Dr. Phillips-Mora’s six hybrids produce on average about three times more cacao than standard varieties; under ideal conditions, the most prolific hybrids can produce six times more cacao.
After an 11-year trial, a hybrid called C.A.T.I.E.-R6 experienced a 5 percent frosty pod rot infection rate, compared to 75 percent infection for a control variety.