Phosphorus extraction and requirements in 'Big Brother' habanero pepper (Capsicum chinense JACQ.) [Extração e requerimento de fósforo na pimenta de cheiro (Capsicum chinense jacq.) 'Big Brother']

The demand for nutrients is one of the three factors that allow to determine the fertilization of crops. The lack of this value can lead to an excess or deficit of fertilization; the first situation involves a negative effect on the environment while the latter does not allow the crop to express its productive potential. The objective of the present study was to determine the internal phosphorus (P) requirement to estimate nutrient demand in 'Big Brother' habanero pepper. In a production system of soilless culture, the effect of five treatments of H2PO4- (0.25, 0.5, 1.0, 1.5 and 2.0meq·l-1) was assessed on the variables: total dry biomass, fruit production, P concentration in leaves, stems, roots, flowers and fruits, and extraction of P (g/plant). The plants were placed in 15 liter containers and volcanic rock was used as substrate. The plants were grown for 90 days after transplantation. Differences in total dry biomass, fruit production, P concentration in roots and fruits, and P extraction by plants were found. The increased production of fruit and total dry biomass were obtained with 1.5meq·l-1 H2PO4-, with 851.71 and 182.26 g/plant, respectively. The treatment with 2.0meq·l-1 H2PO4- had the highest P concentration in roots with 1.43% and reduced significantly the fruit production. The internal P requirement for cultivation of habanero pepper was 0.22%, which was obtained with the concentration of 1.5meq·l-1 H2PO4- and it represented a nutrient demand of 0.47kg P/t of fresh fruit. © 2015, Interciencia Association. All rights reserved