Growth of leaf D and productivity of ‘Imperial’ pineapple as a function of nitrogen and potassium fertilization

Abstract

The cv. Imperial has great commercial potential. Its expansion depends, to a large extent, on the adjustment to the fertilization recommendations proposed in the fertilization and liming recommendation bulletins of the main producing states, in order to have adequate nutritional management. The objective of this study was to verify the growth of leaf D and the productivity of ‘Imperial’ pineapple cultivated under the presence and levels of fertilization of N and K. The experimental design was a randomized complete block with three replicates and treatments were arranged in a factorial scheme according to the Plan Plueba III matrix, with five doses of N (15; 90; 150; 210 and 285 kg ha-1) and five doses of K (21.6, 129.6, 216.0, 302.4 and 410.4 kg ha-1). Data were submitted to analysis of variance. To evaluate the effect of the interaction of N and K doses and days after planting, the response surface technique was used. The elevation of N doses to 285 kg ha-1 provided an increase in the median width of leaf D and SPAD index. The dose of 410.4 kg ha-1 of K2O favored the length, basal width, fresh and dry mass of leaf D. There was a correlation of Pearson of fresh leaf D mass (0.63) and leaf D length (0.97), in relation to productivity. The application of 285 kg ha-1 of N and 410.4 kg ha-1 K2O favors the growth of leaf D, as well as the higher dose of K2O (410.4 kg ha-1) allows productivity of 26.36 t ha-1 of ‘Imperial’ pineapple.