Calagem para o cultivo da Pitaia vermelha em região tropical

Abstract

The cultivation of pitaia has attracted Brazilian producers due to its high market value and its rusticity. Tropicals soils have high acidity and can limit fruit production. Thus, it was evaluated the effects of liming on the growth and productivity of red pitaia, in the first year of cultivation in pot, under tropical conditions. The experiment was conducted a part in a greenhouse and a part in the open sky, in a randomized block design, with five treatments (limestone doses) and four replications. Limestone doses were defined to reach a base saturation range of 20 to 70% using, in t ha-1: 0; 0.61; 1.23; 1.84; and, 2.46. Soil used was a low-fertility Red-Yellow Argisol that was homogenized with the limestone doses and incubated for 90 days. Pots were fertilized with urea, simple superphosphate, potassium chloride and FTE-BR 12. Liming at high pH, Ca, Mg, sum of bases and base saturation, while potential acidity decreases with increasing doses of the limestone. The highest dose resulted in a higher pH (6.7) and V (73%) and, in a lower H+Al (15.4 mmolc dm-3), effectively neutralizing the exchangeable acidity. Liming did not affect growth parameters (number, sum of length, diameter and cladodes thickness) at 180 days. At 360 days, there was effect of doses in number of cladodes. Highest number of cladodes (14.4 units plant-1) corresponded to the estimated dose of 1.3 t ha-1 of limestone with V 49%. The nutritional contents of the cladodes were satisfactory for the vegetative phase. Without effect of liming on the production parameters in the 1st cycle of the red pitaia.