Nutrient reference values for ‘Prata-Anã’ banana in improved chemical fertility soils

Abstract The objective of this work was to establish, through different diagnostic methods, nutrient reference values for ‘Prata-Anã’ banana in improved fertility soil. The study included a database from an experiment conducted in randomized block design, arranged in a 5 × 6 factorial scheme (five doses of K2O - 0; 200; 400; 600 and 800 kg ha-1, supplied by cattle manure and rock powder × six evaluations of leaf nutrition and yield – 210; 390; 570; 750; 930 and 1,110 days after planting), with three replicates, totaling 90 samples. The reference values were determined by the Sufficiency Range, Critical Level by the Reduced Normal Distribution, Boundary Line and Mathematical Chance methods. Plots with high yield, = 36.42 t ha-1 cycle-1, formed the reference population and plots with yield = 45.79 t ha-1 formed the reference subpopulation. The methods were efficient in determining the nutrient reference values of ‘Prata-Anã’ banana. In general, the values established are higher than those reported in the literature, justified by the greater chemical fertility of the soil. Among the diagnostic methods, the Mathematical Chance presented itself as the most accurate for interpreting the nutrient contents in the leaves of ‘Prata-Anã’ banana under improved soil fertility conditions.