Surface Energy Fluxes and Evapotranspiration of a Mango Orchard Grown in a Semiarid Environment

Data from field experiments conducted in the semiarid climatic conditions of northeast Brazil were used to investigate the energy flux relations and evapotranspiration (ET) of a mango (Mangifera indica L.) orchard. The Bowen ratio-energy balance method was applied during the 1998-1999 fruiting cycles to estimate the energy balance components of the mango orchard, while the FAO Penman-Monteith approach was used for determining the reference evapotranspiration (ETo). Results indicated that latent heat flux density (lambdaE) could be obtained, with reasonable precision, as a function of measured net radiation flux density (Rn). The percentage of Rn used as E was higher for the fruit growth and fruit maturation phenological stages, and lower for the flowering and fruit fall stages. For both field campaigns, E was found to be the major component of energy balance, comprising >70% of the available energy. Soil heat flux was always the smaller component, comprising