Contents lists available at ScienceDirect Scientia Horticulturae journal homepage: www.elsevier.com/locate/scihorti Reduction of plant water consumption through anti-transpirants foliar application in tomato plants (Solanum lycopersicum L) Ahmed M. AbdAllah a, ⁎ , Kent O. Burkey b , Alsayed M. Mashaheet c a Department of Natural Resources and Agricultural Engineering, Faculty of Agriculture, Damanhour University, Damanhour, 22516, Egypt b USDA-ARS Plant Physiologist, Plant Science Research Unit, 3127 Ligon Street, Raleigh, NC, 27607, USA c Department of Plant Pathology, Faculty of Agriculture, Damanhour University, Damanhour, 22516, Egypt ARTICLE INFO Keywords: Anti-transpirants Water use efficiency Tomato Water requirements Yield and fruit quality ABSTRACT Optimizing water use efficiency (WUE) is a crucial goal worldwide. However, water savings must not be made at the expense of yield and/or fruit quality to secure economical sustainability for producers. A field study was undertaken to investigate the impact of different anti-transpirants (ATS) on WUE, water requirements (WR), net carbon assimilation rate (P-net), yield and fruit quality of tomato plants (Solanum lycopersicum L.). The aim of this study was to select the most suitable anti-transpirant (AT) that produces a satisfactory yield with less water under field conditions. Three types of ATS were sprayed at first fruit set stage: kaolin (KA) 3% and 5% as a reflective AT, Emulsion of Linus seed Oil tri-ethanolamine (ELO) 1% and 2% as a film forming AT and Fulvic acid (FA) 0.15% and 0.2% as a metabolic AT. The results showed that ATS application increased the relative water content (RWC) especially in the case of FA. However, CO 2 assimilation rate was reduced with the minimum reduction observed under FA application. KA application reduced the canopy temperature (Ct) meanwhile, FA and ELO had no effect. ATS significantly reduced tomato WR where irrigation water reduction ranged between 21% up to 28% of that applied to control plants, with or without significant yield reduction or effects on fruit quality parameters depending on the ATs type and concentration. The results indicated that FA at 0.2% gave the maximum reduction in plant WR (28%) and the minimum reduction of P-net (11.13%) and marketable yield (2.3%), consequently WUE was increased by about 33.45% as compared to the untreated plants. Thus, ATS materials can be used to maintain crop yield and increase WUE in the locations where water resources are limited. 1. Introduction The global climate is changing with a notable increase in average air temperature (Tomasi et al., 2011). The rainfall pattern has become more variable in recent years as a result of climate changes, with severe and unpredictable drought and flooding (Yang et al., 2011). Under those conditions; a strong negative effect is expected on the agricultural production. Furthermore, water is a critical worldwide resource (World Water Assessment Programme, 2012) and agriculture is the largest user of fresh water (70% globally and 85% in Egypt) (FAO, 2015). Thus, optimizing plant WUE without affecting crop yield and/or fruit quality is vital to the limiting use of water for irrigation and to sustainability (Bodner et al., 2015; Medrano et al., 2015a). Sustainable methods to increase crop WUE are gaining importance in arid and semi-arid regions (Debaeke and Aboudrare, 2004). Traditionally, agricultural research has focused primarily on maximizing total production. In recent years, focus has been shifted to maximizing WUE rather than yield (Savic et al., 2011). Because of nearly 95–99% of absorbed water from the soil by plant roots is transpired (Taiz and Zeiger, 2002), there is a high potentiality of water saving through reducing transpiration) Boari et al., 2014; Del Amor and Rubio et al., 2009). ATS have been defined as chemical materials capable of reducing the transpiration rate (TR) when applied to the plant canopy (Glenn et al., 2003). The most obvious use of ATS is conserving soil water by reducing plant consumption, thus, reducing irrigation frequency (Abdallah, 2017; Del Amor et al., 2010; Jifon and Syvertsen, 2003). Indeed, ATS applications for this purpose might be justified when water costs are high and if possibly saved water quan- tities are larger than the application cost (Rosati et al., 2006). Building on that both transpiration and photosynthesis involve https://doi.org/10.1016/j.scienta.2018.03.005 Received 27 August 2017; Received in revised form 28 February 2018; Accepted 2 March 2018 ⁎ Corresponding author at: AL-Abadiaa University campus, Faculty of Agriculture, Damanhour University, Damanhour City, Egypt. E-mail addresses: ph7@damanhour.edu.eg (A.M. AbdAllah), Kent.Burkey@ars.usda.gov (K.O. Burkey), a.mashaheet@damanhour.edu.eg (A.M. Mashaheet). Abbreviations: ATS, Anti-transpirants; AT, Anti-transpirant; WUE, water use efficiency; WR, water requirements; P-net, net carbon assimilation rate; ELO, Linus Seed Oil tri-ethano- lamine; FA, Fulvic acid; KA, kaolin; Ct, canopy temperature; TR, transpiration rate; KY, crop water response factor; PPFD, photosynthetic photon flux density Scientia Horticulturae 235 (2018) 373–381 0304-4238/ © 2018 Elsevier B.V. All rights reserved. T