Please cite this article in press as: Boari, F., et al., Particle film technology: A supplemental tool to save water. Agric. Water Manage. (2014), http://dx.doi.org/10.1016/j.agwat.2014.07.014 ARTICLE IN PRESS G Model AGWAT-3949; No. of Pages 9 Agricultural Water Management xxx (2014) xxx–xxx Contents lists available at ScienceDirect Agricultural Water Management jou rn al hom ep age: www.elsevier.com/locate/agwat Particle film technology: A supplemental tool to save water Francesca Boari a,∗ , Antonio Donadio a , Maria Immacolata Schiattone b , Vito Cantore a a Institute of Sciences of Food Production, CNR, Via Amendola, 122/O, 70125 Bari, Italy b CIHEAM–Mediterranean Agronomic Institute of Bari, Via Ceglie 9, 70010 Valenzano (BA), Italy a r t i c l e i n f o Article history: Available online xxx Keywords: Gas exchange Salt stress Vegetables Water productivity Water stress a b s t r a c t This paper aims to evaluate kaolin application as an effective tool for controlling stomatal conductance (g s ) and transpiration rate (E), in order to enhance tolerance to water stress and salinity and to improve water productivity. Five experiments were carried out under open field conditions in Southern Italy in order to evaluate the effect of kaolin application on the physiological responses of well watered bean and Clementine, tomato under three salinity levels and two irrigation regimes and to try to overcome the vegetables’ transplant shock under two irrigation regimes. Kaolin reduced crop evapotranspiration in bean by 13% and increased photosynthetic water productiv- ity (pWP) and yield water productivity (yWP) by 20 and 9.8%, respectively. In Clementine kaolin reduced E by 26.2% and increased pWP by 30.5%. In tomato kaolin improved the water status of the plant, and reduced g s , net photosynthesis (A) and E under low salinity or well watered conditions. By contrast, under salt stress or drought, kaolin was effective in limiting the reduction in A and reducing leaf temperature (T l ). This increased pWP by 25.3 and 33.1%, respectively, in well watered and water stressed tomato, and by 9.2 and 24.9%, respectively, in the non saline and high saline treatment. Kaolin proved effective in limiting transplant shock under conditions of limited water supply, increasing dry biomass growth rate and biomass water productivity (bWP) by 18.4 and 19%, respectively. Kaolin can be efficiently utilized as an antitranspirant to alleviate the effects of drought and salinity, to reduce transplant shock and to save water in dry regions. © 2014 Elsevier B.V. All rights reserved. 1. Introduction Water is an essential production factor in agriculture, but the imbalances between precipitation and water needs of crops have a significant impact on yields and quality of agricultural products. This problem has now become a real concern, made even more critical by the growing increase in arid conditions due to climate change (Bates et al., 2008). Therefore, the management of water resources is becoming one of the major geostrategic challenges of the 21st century. All strategies that can be used to help save water and improve its productivity thus assume growing importance. The use of kaolin in agriculture, principally to fight pests and for the mitigation of heat stress, may prove to be an opportunity to exploit in the field of water saving, due to its antitranspirant effect. Kaolin-based particle film technology (Pft) has been developed over the past 15 years as a multi-functional, environment-friendly material, that provides effective insect control, mitigates heat ∗ Corresponding author. Tel.:+39 080 5929300. E-mail address: francesca.boari@ispa.cnr.it (F. Boari). stress, and contributes to the production of high-quality fruit and vegetables, as well as being suitable for organic farming (Glenn and Puterka, 2005). Originally, kaolin (Surround ® WP, Engelhard Corporation, Iselin, NJ, Serbios S.r.l., Badia Polesine-RO, Italy) was developed for the suppression of pests in many crops (Pace and Cantore, 2009). In addition, it has been demonstrated that the white kaolin film formed on the leaf surface increases the reflection of incoming solar radiation, changing the radiation and heat balance and reducing the risk of leaf and fruit damage from high temperatures and solar injury (Glenn, 2012). Moreover, the reduction of sunburn in some fruits, such as pomegranate, apple, walnut, citrus and tomato has been widely proven (Cantore et al., 2009; Glenn, 2012; Weerakkody et al., 2010). The mitigation of fruit temperature by kaolin may also contribute to an increase in average fruit weight (Cantore et al., 2009; Lalancette et al., 2005; Saleh and El-Ashry, 2006) and to the improvement of some qualitative aspects of fruits as redness, total soluble solids and anthocyanins concentration (Chamchaiyaporn et al., 2013; Shellie and King, 2013a,b; Yazici and Kaynak, 2009). In addition to the effects mentioned above, Pft can affect sto- matal conductance and gas exchange, as a consequence of the http://dx.doi.org/10.1016/j.agwat.2014.07.014 0378-3774/© 2014 Elsevier B.V. All rights reserved.