Emir. J. Food Agric ● Vol 32 ● Issue 4 ● 2020 281 Growth, production and water consumption of coriander grown under different recirculation intervals and nutrient solution depths in hydroponic channels # Mairton Gomes da Silva*, Tales Miler Soares, Hans Raj Gheyi, Islan Passos Costa, Rafael Souza Vasconcelos Soil and Water Engineering Nucleus, Federal University of Recôncavo of Bahia, Rua Rui Barbosa, 710 - Campus University, 44380-000, Cruz das Almas, Bahia, Brazil #Paper extracted from the doctoral thesis of the frst author presented in the Post Graduate Program in Agricultural Engineering of the Federal University of Recôncavo of Bahia, Brazil INTRODUCTION Coriander (Coriandrum sativum L.) is one of the spices herbs occupying prominent position worldwide, adding favor and aroma to several foods (Rashed and Darwesh, 2015). In addition to its use in cooking, coriander is used in food and pharmaceutical industries due to its medicinal properties (Szempliński et al., 2018; Uitterhaegen et al., 2018). In Brazil, more specifically in the Northeast region, coriander is grown by small and medium farmers, especially for green matter production. The irregular precipitation in this region, according to Brito et al. (2018), is one of the obstacles in the conventional cropping system. Thus, with low water availability the challenge is to maintain coriander quality and yield without affecting household income. Approximately 70% of available fresh water is used by the agricultural sector (Mancosu et al., 2015; Doungmanee, 2016). Hence, irrigated agriculture may be impracticable in some arid and semi-arid regions where water is an increasingly scarce resource for this activity. In order to mitigate water scarcity problems, hydroponic cultivation has been identifed as a suitable solution under this reality of water scarcity (Silva et al., 2017), since it demands less volume of water (reduction of approximately 80%) in relation to conventional cropping systems (Orsini et al., 2018). When the crop is grown in protected environment, climatic adversities are avoided Water is an increasingly scarce resource in arid and semiarid regions. The irregular precipitation makes hydroponics a recommended technique for these regions, since it demands less water compared to conventional cropping systems. Two experiments, one from May to June 2016 (autumn) and other from March to April 2017 (summer-autumn), were conducted in a hydroponic system in PVC tubes, using the Deep Flow Technique (DFT). A 2 x 3 x 2 factorial arrangement in split-plot was used, which consisted of two nutrient solution depths (0.02 and 0.03 m) and three recirculation intervals of the nutrient solution (0.25, 12 and 24 h), with two coriander cultivars (‘Tabocas’ and ‘Verdão’) in the sub-plots, which were cultivated in the same hydroponic channel. Plant height, shoot fresh and dry matters, water consumption, water use effciency and visual quality of the coriander plants were evaluated. The coriander cv. ‘Verdão’ was more tolerant to climatic variations, especially when plants were grown in channels with nutrient solution depth of 0.02 m and recirculation interval of 0.25 h, presenting higher growth and production. The recirculation intervals of 12 and 24 h had a negative effect on the variables evaluated; though, this effect was more signifcant in the summer-autumn experiment, affecting the quality of the plants harvested, especially those of the cv. ‘Tabocas’. It may be concluded that the cultivation of the coriander in the DFT system in PVC tubes is viable, especially in sites with insecure electricity supply. Keywords: Coriandrum sativum L.; Hydroponics; Dissolved oxygen; Water resources ABSTRACT Emirates Journal of Food and Agriculture. 2020. 32(4): 281-294 doi: 10.9755/ejfa.2020.v32.i4.2094 http://www.ejfa.me/ *Corresponding author: Mairton Gomes da Silva, Water and Soil Engineering Nucleus, Federal University of Recôncavo of Bahia, Street Rui Barbosa, 710 - Campus University, 44380-000, Cruz das Almas, Bahia, Brazil. E-mail: mairtong@hotmail.com Received: 11 February 2020; Accepted: 29 May 2019 RESEARCH ARTICLE