Deficit irrigation has been studied for perennial crops to help alleviate water shortage. At certain growing stages, crops which are not sensitive to water stress can receive less than full irrigations. For early-maturing peach cultivars, it has been demonstrated that established peach trees are not sensitive to moderate water stress in the postharvest growth. Field studies were conducted since 2007 to evaluate deficit irrigation management in a 1.6-ha peach orchard in USDA-ARS, Parlier, CA. A wired network of infrared temperature sensors was installed above the orchard for monitoring canopy temperature, which has been used as an indicator of crop water stress. In the first two-years of the study, canopy temperature response from different irrigation treatments was investigated. Mid-day canopy to air temperature difference (ΔT) was found to be most sensitive to water stress. Then we used ΔT value as a primary input for irrigation scheduling for the peach trees. Soil water content and stem water potential were also monitored weekly for each treatment.  In both growing seasons (2009-2010 and 2010-2011), the measured ΔT values showed consistent differences among treatments, which correlated to both soil water content (R² ≈ 0.47-0.53) and stem water potential readings (R² ≈ 0.46-0.65). Irrigation scheduling guided with ΔT was performed very well for furrow irrigation plots at the postharvest period of growing season 2012-2013. The relationship between fruit weight and postharvest irrigation amount indicated that up to 50% water savings could be achieved without impacting fruit size.  Our findings on peach tree deficit irrigation and thermal infrared sensors for guiding irrigation scheduling can provide growers with a practical tool to save water without reduction in yield and fruit quality.