The water production function (Ky) defines the quantitative response of the water deficit to overall yield during a given phenological stage and is a key parameter in deficit irrigation planning in water-scarce scenarios A three-year field trials were carried out on clay loam soil of semiarid India in complete ran-domized blocks with 27 treatments and 2 replicates. Treatments consisted of applying irrigation depths equivalents to 100%, 70% and 40% replenishments of the soil water from the root zone at development, mid-season and end stages of sugarcane. Each treatment was defined to investigate effect of specified water depth on specified phenological stage independently. The actual evapotranspi-ration (ETa) was determined by the field water balance of the root zone while the Ky were calculated according to the FAO-33 report methodology. In particular, during the mid-season and development stages, the referred yield decreases have been shown to be responsive to water deficits. Seasonal Ky values ranged from 1.05 to 1.18 over 3 seasons with an average value of 1.11 showing sugarcane intolerant to water deficit (Ky > 1). Based on the phenological stage ETa, Ky values for development, mid-season and end stages were 0.31, 0.76 and 0.07, respectively. Ky values calculated for development and mid-season stage in this research was different than FAO-33. It could be concluded that during mid-season, water deficit must be avoided; 30 % and 60 % water deficit are appropriate if applied respectively in the in development and end stages.