The reduction in the availability of irrigation water and the increase in pumping costs resulting from the decline in the Ogallala Aquifer make good management decisions more critical for the survival of the farm firm and the success of the agricultural sector in the Texas Panhandle. Response functions for irrigation and percentage potential evapotranspiration (PET) in the production of grain sorghum are estimated. The response functions are transferred into value product functions and combined with an irrigation energy cost function to determine the profit maximizing irrigation strategy. Three management decision variables; total water available, the level of irrigation and the water to meet crop ET requirements are evaluated. Grain sorghum yield, natural precipitation, irrigation, soil moisture content, potential evapotranspiration, and percent potential evapotranspiration (PET) data, collected over the period from 1998 through 2007 by commercial producers participating in the AgriPartners program are used to estimate the response functions. Results indicate that the optimum level of irrigation increases as the price of sorghum increases and decreases as the price of natural gas increases.