On-farm management strategies to conserve water in the Lower Rio Grande Basin is of concern due to reduced water flows for irrigation during periods of drought and increased demand by rapid population growth in South Texas. Citrus production is a main cash crop for growers in South Texas, where this crop has traditionally been under flood irrigation practices. The objective of this study was to measure crop production and water use efficiency (WUE) after converting mature citrus trees previously adapted to flood irrigation to drip and microjet spray irrigation practices. This study was performed at the South farm of the Texas A&M University-Kingsville Citrus Center's South Farm located in Weslaco, TX. Citrus production was monitored from 2002 to 2004, where the impacts of flood, drip and microjet spray irrigation were assessed on grapefruit yield and irrigation use efficiency (IUE). It was found that by the second year after conversion to low-water use systems that these citrus trees out produced flood irrigated trees, with a significantly greater IUE over flood irrigation. This demonstrates that as irrigation waters becomes increasing more scarce and of higher cost to growers in South Texas that conversion to lower water use systems like drip and microjet spray may be more logical and feasible over the long-term.