Abstract
Remotely-sensed canopy temperature from infrared thermometer (IRT) sensors has long been shown to be effective for detecting plant water stress. A field study was conducted to investigate peach tree responses to deficit irrigation which was controlled using canopy to air temperature difference (ΔT) during the postharvest period at the USDA-ARS (U.S. Department of Agriculture, Agricultural Research Service) San Joaquin Valley Agricultural Sciences Center in Parlier, California, USA. The experimental site consisted of a 1.6 ha early maturing peach tree orchard. A total of 18 IRT sensors were used to control six irrigation treatments including furrow, micro-spray, and surface drip irrigation systems with and without postharvest deficit irrigation. During the postharvest period in the 2012–2013 and 2013–2014 growing seasons, ΔT threshold values at mid-day was tested to trigger irrigation in three irrigation systems. The results showed that mid-day stem water potentials (ψ) for well irrigated trees were maintained at a range of −0.5 to −1.2 MPa while ψ of deficit irrigated trees dropped to lower values. Soil water content in deficit surface drip irrigation treatment was higher compared to deficit furrow and micro-spray irrigation treatments in 2012. The number of fruits and fruit weight from peach trees under postharvest deficit irrigation treatment were less than those well-watered trees; however, no statistically significant (at the p < 0.05 level) reduction in fruit size or quality was found for trees irrigated by surface drip and micro-spray irrigation systems by deficit irrigation. Beside doubles, we found an increased number of fruits with deep sutures and dimples which may be a long-term (seven-year postharvest regulated deficit irrigation) impact of deficit irrigation on this peach tree variety. Overall, deployment of IRT sensors provided real-time measurement of canopy water status and the information is valuable for making irrigation management decisions.
Highlights
The United States is the third largest peach producer in the world
When comparing full and deficit irrigation treatment for each irrigation system, we found significantly greater fruit number and weight per tree in FF than FD (F value = 6.3, p = 0.01; F value = 7.7, p = 0.07); larger fruit in SF compared to SD (F value = 4.2, p = 0.05); more doubles in MD than MF
Full and deficit irrigation treatments were applied by furrow, micro-spray and surface drip systems on an early maturing variety of peach during the postharvest season from June to August in 2012 and 2013
Summary
The United States is the third largest peach producer in the world. The total peach production was estimated at 847 thousand tons in 2015 [1]. California was shown to be the largest producer on a state level, accounting for about 70% of the U.S total in the same year. Due to the continuous drought situation and warm winter temperatures in California in recent years, water supplies for agricultural irrigation have declined. Water shortages require farmers and producers to improve water management and utilize limited irrigation water effectively to meet crop demands.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
