Mineral nutrition of cacao (Theobroma cacao L.): relationships between foliar concentrations of mineral nutrients and crop productivity

Abstract

The understanding of the mineral nutritional status of the cacao (Theobroma cacao L.) is one of the main strategies needed to increase the productivity of cacao beans. The main objective of this work is to verify the linear relationships, bivariate and multivariate analysis between the foliar nutrient concentrations of 48 cropping areas and graphically identifying the consistency of this information. For this study, foliar samples collected from cacao cropping areas, with known productivity of dry cacao beans (kg ha⁻¹year⁻¹), were analyzed for N, P, K, Ca, Mg, S, Fe, Mn, Zn and Cu concentrations. The interpretation of the results by the exploratory analysis technique linked to the linear correlation analysis proved to be an essential tool to support nutritional diagnosis systems. The cropping areas with very high productivity equal to or higher than 1600 kg of dry cacao beans ha⁻¹year⁻¹ were positively correlated with the macronutrients K, Ca, and Mg, and the micronutrients Fe, Mn and Zn. The negative correlation of these same high productivity cropping areas with the concentrations of the N and P macronutrients and with the Cu micronutrient may be a phenomenon related to the high nutritional demand for these nutrients in the productive phase.

Keywords:

• crop nutritional management
• leaf analysis
• nutritional status
• sustainable agriculture
• Theobroma cacao L

Acknowledgements

We thank Dr. Marshall Elson for excellent review of this paper.

Additional information

Funding

The project SCA 58-1245-3-237 F of USDA-ARS-FUNPAB partially supported the field and lab activities.