THE USE OF A MECHANISTICMODEL TO PREDICT THE EMERGENCE OF Echinochloa crus-galli in rice

Abstract

The control efficient of the weeds is one of the essential factors to obtain high rice yields, primarily in areas moistened fields, that generally represent higher number of species, probably due to heterogeneous of physical characteristics and chemicals of the soil and moisture contents in the different areas. For the development of these control systems of the unwanted species, it is necessary to anticipate the stage of emergence of weed plants in relation of emergence of the crop. These models where conducted using parameters(cardinal temperature) for the model that were determined by statistic process of linear regression. Using the regression model between the average of elongated function of temperature, determines the base temperature (6,6 and 4,0 °C), preferential (21,7 and 23,6 °C) and maximum (49,0 and 58,8 °C) for the elongation of radicle and hypocotil, respectively. The observed values and calculation for the process of emergence of rice (Echinochloa crus-galli) in different temperatures indicate that the model can establish in an efficient mechanism to predict the desired specie emergence under environmental conditions.