QUALITY OF PINEAPPLE ‘BRS IMPERIAL’ AS A FUNCTION OF N-K DOSES

Pineapple fruit quality is influenced by macronutrients, particularly N and K. This study evaluated the influence of N and K2O doses on physicochemical quality attributes and on the incidence of external and internal defects of ‘BRS Imperial’ pineapple fruits. Four levels of N (0, 160, 320, 550 kg ha^-1) and four of K2O (0, 240, 480 and 600 kg ha^-1) were tested in a randomized blocks experimental design with five replicates, in a 42 full factorial scheme. The doses of N and K₂O influenced all physicochemical variables, except fruit firmness that averaged 10.7 kgf. The N doses reduced titratable acidity (TA) and soluble solids (SS) and increased pH and fruits’ ratio, with average values of 0.31%, 17.9 oBrix, 4.02 and 57.7, respectively, at 550 kg ha^-1 of N. The K₂O doses increased TA and SS and reduced the ratio of fruit, with average values of 0.41%, 19.4 oBrix and 47.9, respectively, at 600 kg ha^-1 of K₂O. The pH quadratic response showed the minimum value of 3.95 at 273 kg ha^-1 of K₂O. Significant Pearson correlations indicated that plants with higher N leaf contents at the time of floral induction produced fruits with lower TA and SS, while plants with higher K leaf contents produced fruits with higher TA and SS. The application of 550 kg ha-1 of N, the fruits showed translucency between 50 and 75% without potassium fertilization and less than 25% at 400 kg ha^-1 of K₂O.

Ananas comosus var. comosus; fertilization; postharvest; titratable acidity; soluble solids; translucency