Plant spacing assessment in cocoa (Theobroma cacao L.) agroforestry systems in the Colombian Pacific region

Cocoa beans produced in the municipality of Tumaco (Colombia) are very attractive for chocolate producers and consumers because of their fine and aromatic characteristics. However, optimal plant spacing that could improve income for cocoa farmers is uncertain. To address the problem, this study was carried out from 2016 to 2017 taking into account two phases. In the first phase, a characterization of the cocoa production system in the Colombian Pacific region was conducted. This characterization included plant spacing, cocoa-associated species, production costs, financial sources, and system yields. In the second phase, an analysis of optimal plant spacing was conducted using the results from the characterization phase. Thus, a linear programming model was developed that utilizes the three plant densities most used by producers (3x3 m, 3.5x3.5 m, and 4x4 m). Labor force, monthly bank fees, and minimum farmer income were considered as constraints of the model. Profitability was established as the objective function. This model was optimized with GAMS software, using the CPlex solver. Plant spacing of 4x4 m (625 plants ha-1) was found to be the optimal solution that maximized profitability. The minimum cocoa bean price required for this solution was 5,000 Colombian pesos kg-1 and the rural capitalization incentive (RCI) needed to be greater than or equal to 40%.