Resumen

SOUSA, Inajá F. de et al. Reference evapotranspiration in the irrigated perimeters of the state of Sergipe. Rev. bras. eng. agríc. ambient. [online]. 2010, vol.14, n.6, pp. 633-644. ISSN 1807-1929.  http://dx.doi.org/10.1590/S1415-43662010000600010.

The knowledge of reference evapotranspiration (ET_o) is essential for the irrigation scheduling of crops throughout the world. This work used daily meteorological data of Class A pan evaporation, maximum and minimum air temperatures, insolation, wind speed at 2 m above surface and relative humidity from 1989 to 1993 for four irrigated perimeters of Sergipe. These data were used for estimating ET_o based on the following methods: Class A pan evaporation, Solar Radiation, Hargreaves & Samani, Linacre and Penman-Monteith (FAO/56). The daily values of ET_o were compared to those obtained by FAO Penman-Monteith method in order to choose the best method of estimating ET_o for the region. The best performance was obtained for those models which used the solar radiation as the data input. The Class A pan evaporation method did not show favorable performance in any irrigated perimeter.

Palabras llave : water requirements; evaporation; Penman-Monteith method; gation scheduling.