Foliar Diagnosis Indexes for Corn by the Methods Diagnosis and Recommendation Integrated System (DRIS) and Nutritional Composition (CND)

Foliar analysis has been an important method for diagnosing the nutritional status of plants. Therefore, this work aimed to determine benchmarks (norms) for interpretation of results of foliar analysis by the methods of Diagnosis and Recommendation Integrated System (DRIS) and Nutritional Composition (CND) and to determine the order of nutritional limitation and the potential response to fertilization (PRA) of corn cultivations. Leaves were sampled and the productivity was determined in 64 different sites in the crop season 2011/2012, and 66 sites were sampled in the crop season 2012/2013. The yields were divided in two sub-populations: high productivity (equal or above 11.795 kg ha^?1) and low productivity (less than 11.795 kg ha^?1). The normal ranges obtained by DRIS and CND methods were similar. The amplitudes of ideal ranges were smaller when compared to the sufficiency ranges found in the Brazilian literature. The development of benchmarks (norms) at regional levels increases reliability in diagnoses.