Interactions between Soil,Leaves and Beans Nutrient Status and Dry Biomass of Beans and Pod Husk of Forastero Cacao: An Exploratory Study

ABSTRACT

In cacao crop the understanding of the multiple relationships between bean and pod husk dry biomass and mineral nutrition in the soil-plant system is scarce. The main objective of this work is to verify the linear, bivariate and multivariate correlations between the mineral nutrient concentrations in the soil, leaves and beans of 53 cacao trees with known dry biomass of cacao beans and pod husk, and further graphically identifying the consistency of these information. For this study, soil samples, leaves and fruits (pod husk and beans) were collected from each cacao trees, for the analysis of nitrogen-N, phosphorous-P, potassium-K, calcium-Ca, magnesium-Mg, iron-Fe, manganese-Mn, zinc-Zn and cooper-Cu mineral nutrient 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 studies related to mineral nutrition in the soil-plant system. Foliar N concentration were directly related to the high and very high dry biomass classes of cacao beans. Levels of exchangeable Ca and Mg in the soil were inversely correlated with the dry biomass of cacao pod husk (DBCH), in contrast to results with the positive correlations of these nutrients in the leaves and cacao beans data sets. The foliar concentrations of Zn, Mn, Fe and Cu are shown to be more positively associated with DBCH than dry biomass classes of cacao beans. The concentrations of Fe, Mn and Cu in dry cacao beans show such similar pattern of association with dry biomass of pod husk and beans.