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In the past ten years, smart irrigation controllers have been developed by a number of manufacturers and have been promoted by water purveyors in an attempt to reduce excessive irrigation. Legislation has been introduced in California and Texas and passed in Florida mandating or incentivizing the use of these controllers. As a result of the interest in smart controllers, their use is increasing in new installations and retrofits of residential and light commercial irrigation systems. A number of controlled research studies using formal experimental design and statistical analyses indicate substantial water savings of anywhere from 40% to more than 70% when using these devices; however, real-world savings in larger pilot-scale projects indicate savings of typically less than 10%. Reasons for the divergence between the apparent potential savings and the realized savings in pilot projects are related to the lack of: targeting of high irrigation users (on either a relative or absolute scale), education for contractors and end users, and timely follow-up to assess water savings. In addition, much of the scientific research on smart controllers has been conducted in humid regions where higher potential savings are likely due to irrigation needed only to supplement rainfall. Future pilot projects should include comprehensive educational components aimed at irrigation sites with potential irrigation savings based on estimated landscape irrigation demand from climatic variables (i.e., high irrigation users). [ABSTRACT FROM AUTHOR]

Over the past decade, citrus production has sharply decreased in Florida because of citrus greening or Huanglongbing (HLB), a disease that reduces fruit yield and quality and eventually kills the citrus trees. With the increased mortality and need to resetting trees, the demand for healthy trees from citrus nurseries has risen drastically in the last few years. To meet the demand and accelerate tree growth, the citrus nursery industry should use modern horticultural practices such as more efficient irrigation methods, fertigation, and more vigorous rootstocks. This study evaluated the effect of subirrigation systems in tree production time, water and fertilizer inputs, and plant growth of commercial citrus rootstocks cultivated in treepots. We tested five irrigation methods [three ebb-and-flow subirrigation systems triggered at specific volumetric water contents (θ, 0.24, 0.36, and 0.48 m3 m−3), capillary mats, and a conventional drip irrigation system], and six commercial rootstocks (Kuharske, UFR-2, UFR-16, US-802, US-812, and X-639). The experiment was arranged in a split-plot design, with the main plot consisting of the five irrigation methods and sub-plots the different rootstocks. Ebb-and-flow subirrigation benches conserved 98% more water than conventional drip irrigation. Rootstocks grown under ebb-and-flow systems reached adequate stem diameter for grafting four weeks before the drip irrigation. Pummelo hybrids used in this study (UFR-16, UFR-2, and US-802) were 55% taller, 24% thicker, and 150% heavier on biomass production than the other varieties tested, irrespective of the irrigation method utilized. Although the substrate electrical conductivity was higher in all subirrigation methods, the values were below 1 dS cm−1, not causing symptoms of osmotic stress in plants. Our results show that the ebb-and-flow subirrigation system at θ of 0.24 m3 m−3 is the best option for accelerating citrus growth in treepots with peat: perlite substrate and to conserve water in Florida nurseries in comparison to capillary mats and drip irrigation. • Ebb-and-flow subirrigation was successfully automated for citrus rootstock growth. • Ebb-and-flow benches used less water than capillary mats and drip irrigation. • Rootstocks were ready for grafting earlier at the substrate threshold θ of 0.24 m3 m−3. • Accelerated growth of citrus in treepots at the substrate threshold θ of 0.24 m3 m−3. [ABSTRACT FROM AUTHOR]