Matéria seca, concentração e acúmulo de nutrientes em mamoneira, influenciados pelas doses de fósforo

Abstract

In order to evaluate the effect of different phosphorus doses on biomass production and nutrient concentration and accumulation, an experiment was conducted at the Agricultural Science Center of the Federal University of Alagoas, located in Rio Largo, Alagoas, Brazil. The completely randomized block design was used with four replications in a factorial scheme 5 × 2, consisting of five P doses (0, 20, 40, 60 and 80 kg ha-1) provided in the form of triple superphosphate, and two castor oil plant varieties, BRS 149 Nordestina and BRS 188 Paraguaçu. 50 days after the transplanting (DAT), the +4 leaves were collected to determine the N, P, K, Ca, Mg, Mn, Cu and Zn concentrations in these tissues, and, at the end of the cycle, i.e. 150 DAT, the plants shoots were collected to obtain the dry matter, N, P and K accumulations. Given the results, it was observed that the phosphate fertilization influenced only the dry matter, nitrogen, phosphorus and potassium accumulations, and the varietal effect was obtained only for the N and Ca leaf contents. The BRS 149 Nordestina variety had the highest N contents and the lowest Ca contents.