The main objective of this study was to find an efficient method in determining the evapotranspiration of sugarcane with little requirement for environmental measurements. Field experiments were conducted in the Distillery Miriri S.A (UNIAGRO), located in the muncipality of Capim, Paraíba state, Brazil, from October 2009 to August 2010. The data for determining evapotranspiration were obtained in the rainfed and the data to determine the reference evapotranspiration were obtained in PCD (Data Collection Platform), INPE. The survey results allow to conclude that the method of Priestley-Taylor showed values very close to those of the reference evapotranspiration throughout the crop cycle. Moreover, the method of Priestley-Taylor with the adjusted coefficient showed the best performance in the evapotranspiration of sugarcane when compared with measurements obtained by the method of soil water balance. The results also indicate that the coefficient α of Priestley-Taylor varies considerably depending on the growth stage of the crop.
energy balance; Bowen ratio; soil water balance
