Variety-specific responses of lettuce grown in a gravel-film technique closed hydroponic system to N supply on yield, morphology, phytochemicals, mineral content and safety

Abd El-Rehem, 2009, Cabbage nutritional quality as influenced by planting density and nitrogen fertilization, Fruit, Vegetable and Cereal Science and Biotechnology, 3, 68 Addiscott, 2004, Nitrate and human health, Soil Use and Management, 20, 98, 10.1079/SUM2004256 AOAC International, 1995, Guidelines for collaborative study procedures to validate characteristics of a method of analysis, Journal–Association of Official Analytical Chemists, 78, 143A Becker, 2015, Nitrogen limited red and green leaf lettuce accumulate flavonoid glycosides, caffeic acid derivatives and sucrose while losing chlorophylls, β-carotenes and xanthophylls, PLoS ONE, 10, e22, 10.1371/journal.pone.0142867 Chiesa, 2009, Quality of fresh cut lettuce (Lactuca sativa L.) as affected by lettuce genotype, nitrogen fertilization and crop season, Advances in Horticultural Science, 23, 43 Daniele, 2013, An integrated model for the management of nitrogen fertilization in leafy vegetables, 18174 EFSA (European Food Safety Authority), 2008, Nitrate in vegetables scientific opinion of the panel on contaminants in the food chain, The European Food Safety Authority Journal, 689, 1 Feyman, 1991, Effect of nitrogen fertilization on yield, storage losses and chemical composition of winter cabbage, Canadian Journal of Plant Science, 71, 943, 10.4141/cjps91-135 Heimler, 2007, Polyphenol content and antioxidative activity in some species of freshly consumed salads, Journal of Agricultural and Food Chemistry, 55, 1724, 10.1021/jf0628983 IM (Institute of Medicine), 2000 Konstantopoulou, 2010, Nutritional quality of greenhouse lettuce at harvest and after storage in relation to N application and cultivation season, Scientia Horticulturae, 125, 93.e1, 10.1016/j.scienta.2010.03.003 Lee, 2000, Preharvest and postharvest factors influencing vitamin C content of horticultural crops, Postharvest Biology and Technology, 20, 207, 10.1016/S0925-5214(00)00133-2 Leja, 2007, Some parameters of antioxidant capacity of red cabbage as related to different forms of nutritive nitrogen, Folia Horticulturae, 19, 15 Lynch, 2003, Iron and ascorbic acid: Proposed fortification levels and recommended iron compounds, Journal of Nutrition, 133, 2978S, 10.1093/jn/133.9.2978S Maboko, 2013, Effect of plant spacing and harvesting frequency on the yield of swiss chard cultivars (Beta vulgaris L.) in a closed hydroponic system, African Journal of Agricultural Research, 8, 936 Mahlangu, 2016, Lettuce (Lactuca sativa L.) growth, yield and quality response to nitrogen fertilization in a non-circulating hydroponic system, Journal of Plant Nutrition, 39, 1766, 10.1080/01904167.2016.1187739 Mampholo, 2016, Phytochemicals and overall quality of leafy lettuce (Lactuca sativa L.) varieties grown in closed hydroponic system, Journal of Food Quality, 39, 805, 10.1111/jfq.12234 Van der Merwe, 2016 Nicolle, 2004, Characterisation and variation of antioxidant micronutrients in lettuce (Lactuca sativa Folium), Journal of the Science of Food and Agriculture, 84, 2061, 10.1002/jsfa.1916 Ntsoane, 2016, Variety-specific responses of lettuce grown under the different-coloured shade nets on phytochemical quality after postharvest storage, Journal of Horticultural Science, 19, 520 Petropoulos, 2016, Yield and quality of lettuce and rocket grown in floating culture system, Notulae Botanicae Horti Agrobotanici Cluj-Napoca, 44, 603, 10.15835/nbha44210611 Pitura, 2015, Influence of nitrogen doses on the chemical composition and proportions of nutrients in selected vegetable species, Journal of Elementology, 20, 667 Poulsen, 1995, Influence of growth conditions on the value of crisphead lettuce, Plant Foods for Human Nutrition, 47, 157, 10.1007/BF01089265 Qadir, 2017, Manipulation of contents of nitrate, phenolic acids, chlorophylls, and carotenoids in lettuce (Lactuca sativa L.) via contrasting responses to nitrogen fertilizer when grown in a controlled environment, Journal of Agricultural and Food Chemistry, 65, 10003, 10.1021/acs.jafc.7b03675 Rather, 1999, Response of yield and quality of cauliflower varieties (Brassica oleracea var. botrytis) to nitrogen supply, The Journal of Horticultural Science and Biotechnology, 74, 658, 10.1080/14620316.1999.11511169 Sady, 2010, Effect of nitrogen fertilization on sugars, ascorbic acid and phenolic compounds in white cabbage (Brassica oleracea var. Capitata alba L.), Acta Scientiarum Polonorum Hortorum Cultus, 9, 41 Stefanelli, 2010, Minimal nitrogen and water use in horticulture. Effects on quality and content of selected nutrients, Food Research International, 43, 1833, 10.1016/j.foodres.2010.04.022 Stefanelli, 2011, Reduced nitrogen availability during growth improves quality in red oak lettuce leaves by minimizing nitrate content, and increasing antioxidant capacity and leaf mineral content, Agricultural Sciences, 2, 477, 10.4236/as.2011.24061 Tei, 2002, Critical nitrogen concentration in processing tomato, European Journal of Agronomy, 18, 44, 10.1016/S1161-0301(02)00096-5