DRIS norms universality in the corn crop

Abstract

The Diagnosis and Recommendation Integrated System (DRIS) approach evaluates plant nutritional status. The DRIS is based on a comparison of crop nutrient ratios with optimum values from a high-yielding group (DRIS norms). Several researchers affirm that once DRIS norms based on foliar composition has been developed for a given crop; they are universal and applicable to that particular crop grown at any place and at any stage of its development. But different diagnoses with DRIS norms established for the same crop but under different growth conditions have been found in the literature. The objectives of our study were (i) to evaluate the confidence intervals of four DRIS norms of corn crop, (ii) to compare corn nutritional diagnosis with four DRIS norms, and (iii) to evaluate the universal use of DRIS norms in corn crop. Four DRIS norms were used to evaluate corn nutritional status. Different nutritional diagnoses were given when using these four DRIS norms. The universal application of these four DRIS norms should not be recommended to evaluate corn nutritional status. In the absence of DRIS norms locally calibrated, norms developed under one set of conditions only should be applied to another if the nutrient concentrations of high-yielding plants from these different set of conditions are similar.