Resumo

BRIONES ENCINIA, Florencio; CASTRO NAVA, Sergio; LOPEZ SANTILLAN, José Alberto  e  TRINIDAD SANTOS, Antonio. Optimal analytical and economic of models applied in agricultural experimentation. Agric. Téc. Méx [online]. 2009, vol.35, n.1, pp.89-95. ISSN 0568-2517.

In research on crop fertilization it is frequent the application of pseudocuadratic models as a response surface approach. However, the determination of analytic and economic optimum yields may present difficulties, particularly when the corresponding values lie out of the exploration range, when a saddle point is obtained or when is impossible to reach an analytic solution for the equation. To obtain the economic optimums in a pseudocuadratic model, the use of numerical calculation methods and a statistic computer system, is required. The objectives of this work were: to present a procedure for calculating the analytical and economic optimum yields on a pseudocuadratic general model with one and two factors and to test it with real experimental data. The model was developed at the Unidad Académica Multidisciplinaria Agronomía y Ciencias de la Universidad Autónoma de Tamaulipas, in 2006 and was applied on experimental data obtained from maize fertilization trials carried out under rainfed conditions at two sites in the state of Puebla, Mexico. For one factor, the optimal economic yield (4 5 69.45 kg ha^-1) was obtained with 13 8.95 kg ha^-1of nitrogen. For two factors, the optimal yield was 2 295.20 kg ha^-1 with 110 kg ha^-1 of nitrogen and 0 kg ha^-1 of phosphorous.

Palavras-chave : analytic and economic optimum; pseudocuadratic model.