Balanco hidrico no solo cultivado com mangueiras.

The experimental part of the present research was conducted in the irrigated perimeter of Bebedouro, Petrolina, PE,Brazil (Latitude: 09009`S, Longitude: 40022`W; altitude: 365.5m) in the years of 1998 and 1999, in a drippingirrigated plot area of 9,880 m2 seven years old mango orchard, cv. ?Tommy Atkins`, planted in a spacing of 5mbetween plants by 8m between arrays. This work evaluated the efficiency of the soil water balance for determiningthe evapotranspiraration throughout the mango orchard productive cycle. The errors analysis indicated that, for thesubmedian San Francisco river region soil and climate conditions, the soil water balance method for estimatingevapotranspiration should not be applied for periods lower than a week. Also, according to the obtained results, thesoil water balance method is only efficient in the estimates of the evapotranspiration of mango orchard whenconsidering the term regarding to the deep drainage or water ascent