Organic and Chemical Fertilization of Cacao (Theobroma cacao L.) Clones in an Agroforestry System

Abstract

Cacao (Theobroma cacao L.) yield in Tumaco, Nariño, is one of the lowest in Colombia, making this activity unattractive to farmers, despite having one of the best cacaos in the world. Researchers affirm that proper crop management and nutrition of cacao plants are the most effective alternatives to increase cacao yields. Therefore, this research aims to evaluate the effect of organic and mineral fertilization on the yield of cacao clones in an agroforestry system for two years. We used a randomized complete block design by arranging treatments in split plots, being three cacao clones (CCL1, CCL2, and CCN51) the main plot and different fertilization regimes (chemical, organic, and a mixture of chemical and organic fertilizers) the subplots plus a control. The variables assessed were number of pods per tree, pod weight, number of grains per pod, fresh and dry grain weight ratio, and quality parameters of the dry grains. The results showed that the local clone CCL2 had a higher yield than the regional average (1.5 vs. 0.3 t, respectively) under mineral fertilization. The CCL2 and CCN51 exceeded the break-even point for cacao in Tumaco. The economic analysis further showed that for each Colombian peso invested in fertilizers for the regional clone CCL2, the farmer recovers COP 4.7. To sum up, the selection of outstanding regional clones together with their fertilization is a viable alternative to increase cocoa yield in Tumaco, Colombia.