The productivity of cupuassu orchards in the Amazon region has been gradually declining, probably due to the reduction in soil fertility, calling for fertilization. In the absence of technical recommendations to calculate the nutrient demand of an orchard, the use of the Integrated Diagnosis and Recommendation (DRIS) may represent an alternative to fill this gap. The purpose of this study was to evaluate the diagnoses based on different formulas and criteria of interpretation of DRIS indices of cupuassu orchards. The contents of N, P, K, Ca, Mg, Zn, Mn, Cu, and Fe were determined in leaf samples from 153 orchards and diagnosed by three DRIS formulas: Beaufils, Jones and Wadt and coleagues. The DRIS indices were interpreted by: DRIS including dry matter (M-DRIS), which separates the nutrients in limiting or non-limiting, and the method of the response potential to fertilization, which classifies the nutritional status of elements in insufficient, balanced or excess. Critical levels of foliar nutrients were also adopted for cupuassu trees from the literature. The diagnoses based on the different interpretation criteria of the DRIS indices were not consistent with each other or with the threshold method, except for the formula Wadt and coleagues. The diagnoses by the Wadt and coleagues formula were more consistent, regardless of the criteria used for interpretation. The suggested values to assess the nutritional status by the threshold method were not satisfactory.
nutritional status; leaf analysis; Amazon region; fruit trees; Theobroma grandiflorum
