Researchers measured 331 seventeen-year-old grafted cacao trees across five cropping systems and four genotypes in a long-term trial in Alto Beni, Bolivia. They separated each tree into the leafy crown, where carbon is fixed, and the leafless zone of scaffold branches below, where flowers and pods form.
Conventional and organic monocultures produced the most vigorous trees, with thicker branches, more branches and larger crowns. Dynamic agroforestry trees were smallest and lowest yielding. Genotype ICS1 × IMC67 was the weakest, while IIa22 produced the most pods.
Across all systems and genotypes, pod production was tied to the number of 1st- and 2nd-order scaffold branches and the diameter of 1st-order branches. A seven-type architectural typology based on branch counts predicted yield. Trees with a single productive 1st-order branch produced about 37% fewer pods than the reference type, while the best types produced up to 54% more. Each extra centimeter of 1st-order branch diameter raised yearly pod production by about 16%.
Crown geometry was a secondary factor. Larger crown surface and higher foliage increased yield, and the leafy crown stayed at about 40% of tree height across all types.
The authors recommend training young trees to develop three to five scaffold branches, keeping mature crowns near 40% of tree height, and protecting vigorous scaffold wood when pruning. Standard advice focused on height limits and canopy opening may remove productive wood. The results come from one site and are associations rather than tested pruning interventions.
