Interpolation methods for the description of the spatial dependence of the leaf chlorophyll content in cocoa trees. In: Agrotrópica v. 28 p. 13-22, 2016.

Abstract

The use of the relative chlorophyll content for the evaluation of nitrogen nutrition in plants has been considered an important alternative for agricultural management. The objective of this work was to study the temporal variability of leaf chlorophyll content in cocoa plants as well as to compare the efficiency of ordinary kriging and inverse distance weighted in describing the spatial dependence structure. The study was conducted in an experimental area in Ilhéus city, Bahia state, Brazil, in a regular grid with 120 sampling points. Chlorophyll content in cocoa leaves was determined during three months using a CFL 1030 chlorophyll meter. Data were analyzed by classical statistics and geostatistics. To determine the temporal stability, a linear correlation analysis was performed between the original values measured at different times. The performance of the interpolators was obtained and compared using the criterion of the average error. The leaf chlorophyll contents showed low temporal stability throughout the evaluation period. The ordinary kriging estimated data with fewer errors as well as efficiently described the spatial dependence of the leaf chlorophyll content. The inverse distance weighted generated maps with greater spatial discontinuity.