Diseases
Fungal diseases of cacao trees result in economic loss in Latin America and Africa. Phytophthora spp. are the most important of the cacao pathogens; these fungi cause black pod disease. The fungus grows on the ripening pod and seed coats. As the mycelia develop the pod blackens and is unusable.
Witches' broom, Crinipellis perniciosa, is the other serious fungal pathogen of cacao trees in Latin America. The fungus grows in the new buds, flowers, and seeds. Seeds will not develop on infected plants. The disease can cause yield losses of 75 percent in susceptible varieties
Biological Controls
In 2011, USDA researchers reported fungi in disease-free Peruvian cacao trees. The fungi may provide protection against diseases such as witches' broom disease either by stimulating the immune system of the plants or through direct parasitism or antibiotic effects against pathogens.