The United Nations Food and Agricultural Organization (FAO) approved the Hargreaves-Samani formula (HAR-85) as an alternative to standard Penman-Monteith method (FAO-PM) for estimating grass reference evapotranspiration (ETo). With much less data demand, HAR-85 is unequivocally useful where meteorological variables are often scarce, incomplete or unavailable. Herein, we evaluate against FAO-PM ...
