GROWTH AND FERTILIZATION PROGRAM FOR LISIANTHUS BASED ON NUTRIMENTAL ACCUMULATION

Abstract

LLisianthus is a species that complements the production of flowers and supplies the demand for ornamentals, however, as to the nutrition there is a need to propose scientifically proven fertilization rates. The objective of the present study was to model the accumulation of nitrogen (N), phosphorus (P), potassium (K), calcium (Ca) and magnesium (Mg), and thus design a fertilization rate for this species. Samples were taken every 10-15 days to determine the accumulated dry biomass and nutrient content; the data were used to estimate the two- or three-segment models. Total dry matter showed a twostep pattern; in the first one there was a linear increase from the transplant to the few days after the beginning of the flowering, and later the increase had a marked change in the slope. The extraction of N, P and K showed three stages; the first was of rapid accumulation, the intermediate stage had a slower rate, and in the final stage there was a marked increase in the absorption. In contrast, the extraction of Ca and Mg exhibited a two-stage behavior. Considering an efficiency of 50%, 40%, 80%, 75% and 75% in the use of N, P, K, Ca and Mg, respectively, and a planting density of 64 m^-2 plants, the total demand (in gr m^-2) of lisianthus was: 16.27 of N, 4.05 of P, 8.14 of K, 2.58 of Ca and 3.12 of Mg.