INITIAL GROWTH AND NUTRIENT ACCUMULATION IN PITAYA PLANTS AT DIFFERENT PHENOLOGICAL STAGES1

Abstract

ABSTRACT Information on nutritional management of pitaya crops are scarce. However, understanding the growth and nutrient accumulation in these plants at different developmental stages can assist in the development of rational soil fertilizer application programs for pitaya crops and decrease production costs. Thus, the objective of this work was to evaluate the growth and nutrient accumulation in pitaya plants throughout the crop cycle. Cladodes of pitaya plants of the Hylocereus setaceus species were grown in polyethylene pots containing a Typic Hapludult (Argissolo Vermelho-Amarelo Eutrófico) under full sun. The treatments consisted of six sampling times: 0, 60, 120, 180, 240, 300, and 360 days after planting (DAP). A randomized block experimental design with four replications was used. Four plants were sampled and evaluated for growth and nutrient accumulation at each sampling time. The pitaya plants presented an exponential growth up to 360 DAP and high nutrient absorption between 300 and 360 DAP. The nutrient and Na accumulations in the cladodes, in decreasing order, were: 3.91 (K), 2.56 (Ca), 1.95 (N), 1.24 (P), 0.45 (Mg), 0.30 (S), and 0.06 (Na) g plant-1, and 14.86 (Zn), 12.72 (Fe), 12.37 (Mn), 5.37 (B), and 1.04 (Cu) mg plant-1. The highest relative growth rate and relative nutrient absorption rate were found between 60 and 120 DAP.