Validação do modelo ceres-rice para a cultivar IRGA 424

Abstract

CERES-Rice is a model that simulates the development and productivity of a cultivar. To achieve this, it is necessary to obtain the genetic coefficients of the cultivar through the calibration process. The genetic coefficients describe the behavior of the plant in the soil-plant-atmosphere system. The gaol of the present work was to calibrate and validate the CERES-Rice model, included in the DSSAT platform, to estimate the productivity for the cultivar IRGA 424 in Rio Grande do Sul, using only information found in the literature. The work also aims to develop na algorithm to aid in the formatting of meteorological data, the comparison of the result obtained through the CERES-Rice model with that estimated by SimulArroz and also to evaluate the response obtained by the CERES-Rice model when estimating the date of flowering. After the application of the algorithm, the meteorological data for use in the DSSAT and SimulArroz were exported successfully. Although no extra features have been implemented, the method used provides the possibility of include new functions, such as data-filling techniques. For the calibration process of the genetic coefficients, the GENCALC module was used, also included in the DSSAT. After the calibration process, the other validations were performed. The results for productivity were considered acceptable, since most of the values were below 15%, only one of the results showed an error of 16,88%. The values found by the CERES-Rice model obtained a smaller error than the SimulArroz. However, the statistical analysis indicates that both results were considered good. Despite this, the paper does not recommend replacing the SimulArroz model in the simulations of Rio Grande do Sul, but proposes an analysis in the CERES-Rice model, to investigate the possibility of incorporating parts of its source code into the SimulArroz model, as well as there are from ORYZA2000 and InfoCrop. The results of the simulation obtained values in days after sowing inferior to those of the experimental values, with a mean of 23 days for the data of Cachoeirinha and 25 for those of Uruguaiana. This result with the genetic coefficients used in the present study, the model was not able to estimate the date of flowering within the acceptable limits, being necessary to perform a new adjustment of coefficients.