Phosphate application influences the initial growth and accumulation of phosphorus and nitrogen in UMBU (Spondias tuberosa Arruda Camara)

Abstract The objective of the current work is to evaluate the influence of phosphorus (P) on the accumulation of dry matter as well as the nitrogen (N) and P uptake by the umbu. The experiment was conducted under greenhouse conditions and seeds were placed in a 3-liter pot containing Yellow Latosol soil. The experimental design was entirely randomized, employing different P levels (0; 8; 16; 32 and 64 mg kg-1 of soil). The experiment was concluded 108 days post planting, and the characteristics of growth as well as the N and P uptake were evaluated. The P was found to be significant as it promoted an increase in stem diameter, which could improve grafting and establishment of the plants in the field. The least value of Total Dry Mass (TDM) was obtained when the plants were cultivated in the absence of P. Up to the dose of 32 mg of P the increase in the accumulation of Dry Mass by Absorbing Root (DMAR) was slow and gradual; however, between the doses of 32 and 64 mg of P, a substantial accumulation of dry mass in this plant region was observed. The deficiency of P significantly reduced the uptake of P and N, although it did not change the N: P ratio. Phosphorus fertilization allowed greater growth of the xylopodium, local where water and nutrients storage ocurrs; therefore, P fertilization may contribute to increased drought tolerance of this specie. The concept of P-fertilization is highly significant for the growth of the umbu.