SUGARCANE NUTRITIONAL DIAGNOSIS WITH DRIS NORMS ESTABLISHED IN BRAZIL, SOUTH AFRICA, AND THE UNITED STATES

ABSTRACT The Diagnosis and Recommendation Integrated System (DRIS) approach evaluates plant nutritional status. The Diagnosis and Recommendation Integrated System 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 have 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. The objectives of this study were (i) to evaluate the confidence intervals of three DRIS norms of sugarcane crop, (ii) to compare sugarcane nutritional diagnosis with three DRIS norms, and (iii) to evaluate the universal use of DRIS norms in sugarcane crop. Sugarcane DRIS norms were tested. Means for nitrogen (N)/phosphorus (P), N/calcium (Ca), N/copper (Cu), manganese (Mn)/N, N/zinc (Zn), C...