Irrigation Application Using Evapotranspiration-based Irrigation Controllers

Despite limited water resources, typical homes in Florida have in-ground irrigation systems utilizing automated timers that have been shown to increase outdoor water use. The need for landscape irrigation is likely to continually grow with increased population growth and home construction in Florida. Evapotranspiration-based controllers, or ET controllers, are irrigation controllers that use an estimation of evapotranspiration (ET) to schedule irrigation. Three ET controller systems were selected to evaluate their ability to apply irrigation compared to two time-based schedules developed from UF-IFAS recommendations. Five treatments were replicated four times totaling 20 plots, each measuring 7.62 m x 12.2 m. The plots, constructed at the OF Gulf Coast Research and Education Center, were partitioned into 65% St. Augustinegrass (Stenotaphrum secundatum) and 35% mixed-ornamentals to represent a typical Florida landscape. The irrigation treatments were as follows: Smart Line Series controller (Weathermatic, Inc., Dallas, TX), Intelli-sense (Toro Company, Inc., Riverside, CA), Smart Controller 100 (ETwater Systems LCC, Corte Madera, CA), a time-based treatment derived from UF-IFAS recommendations, and a time-based treatment that was 60% of UF-IFAS recommendations. Results were quantified by comparing weekly water application depths and turfgrass quality.