Zinc-biofortified lettuce in aeroponic system

• Published in: Journal of plant nutrition 2021-08, Vol.44 (14), p.2146-2156
• Main Authors: Meneghelli, Caroline Merlo, Fontes, Paulo Cezar Rezende, Milagres, Carla do Carmo, da Silva, José Maria, Junior, Edimaldo Garcia
• Format: Article
• Language: English
• Subjects: Accumulation; Aeroponics; Cultivars; Dosage; Evaluation; Fertilization; Lactuca sativa L; Leaves; Lettuce; micronutrient; Nutrient deficiency; nutrient solution; Roots; Stems; Toxicity; Transplantation; Vegetables; Zinc; Zinc sulfate
• ISSN: 0190-4167; 1532-4087
• DOI: 10.1080/01904167.2021.1889587

Zinc (Zn) deficiency can be mitigated by several procedures, including food biofortification. Agronomic biofortification is a process that aims to increase the concentration of mineral elements in plants through fertilization. Therefore, the objectives of this study were to evaluate the possibility of producing zinc-biofortified curly lettuce in an aeroponic system and to establish the appropriate zinc dose to be used. The experiment was conducted in a greenhouse under aeroponic system, with the Filó lettuce cultivar. The treatments consisted of four doses of Zn (25, 50, 75 and 100 μmol L −1 of Zn), plus the control (0 μmol L −1 of Zn). The source of Zn used was ZnSO 4 .7H 2 O. The experiment was set up in a completely randomized design with four repetitions. The nutrient solution was changed once a week and monitored daily by measuring the pH. Thirty-seven days after transplantation, the following variables were evaluated: fresh shoot mass, dry mass of leaves, stem and root system, Zn concentrations and accumulation in leaves, stem and root, shoot and root system ratio, total root length, specific root surface area and total root volume. No symptoms of Zn toxicity were seen the plants. The greatest accumulation of Zn occurred in the roots, followed by the leaves and stem. Lettuce shoot mass increased to 224.19 g with increasing Zn concentration in the solution to 47.2 μmol. Under the conditions of study, the curly lettuce cultivar can be considered biofortified with 50 μmol L −1 of Zn, without affecting the productive characteristics of the crop.