02404naa a2200325 a 450000100080000000500110000800800410001902400570006010000190011724501320013626000090026850001730027752011660045065000510161665000190166765000200168665300220170665300360172865300300176465300310179465300250182570000190185070000200186970000210188970000170191070000170192770000200194470000240196477300900198821342112021-09-10       2017    bl uuuu     u00u1 u    #d7 ahttps://doi.org/10.1590/S0100-204X20170009000102DOI1 aDIAS, J. R. M.  aNormal nutrient ranges and nutritional monitoring of 'Pêra' orange trees based on the CND method in different fruiting stages.  c2017  aTítulo em português: Faixas normais de nutrientes e monitoramento nutricional de laranjeiras 'Pêra' com uso do método CND em diferentes estádios de frutificação.  aThe objective of this work was to determine reference values for evaluating the nutritional status of 'Pêra' orange (Citrus sinensis) trees in different fruiting stages, using the compositional nutrient diagnosis (CND) method. The study used 243 leaf samples from 81 plots, with samplings performed in plants bearing fruits with three and six months of age, and also in the main harvest (nine months). Plots with productivity higher than 30 Mg ha-1 were selected for the establishment of reference standards. Three normal ranges were evaluated for each nutrient in the reference population, comprehended by the confidence interval (CI) of the foliar content averages, by the mean±standard deviation (±SD), and by the mean±?SD. Regardless of the normal range of nutrients used, the leaf sampling periods interfered with the nutritional status of 'Pêra' orange tree. The normal ranges obtained from the criteria CI and ±?SD of the nutrient contents observed in the reference population frequently provided similar nutritional diagnoses. Zn, Ca, and Fe are the elements that most often limit the production of 'Pêra' orange in the state of Amazonas, Brazil.  aDiagnosis and Recommendation Integrated System  aCitrus Limonia  aCitrus Sinensis  aAmostragem foliar  aÍndice de balanço nutricional  aNutritional balance index  aPopulação de referência  aReference population1 aWADT, P. G. S.1 aPARTELLI, F. L.1 aESPINDULA, M. C.1 aPEREZ, D. V.1 aSOUZA, F. R.1 aBERGAMIN, A. C.1 aDELARMELINDA, E. A.  tPesquisa Agropecuária Brasileira, Brasília, DFgv. 52, n. 9, p. 776-785, ago. 2017.