Agronomic biofortification with zinc in curly lettuce cultivars

In underdeveloped countries, zinc deficiency is a public health problem. The main foods consumed in these countries have low levels of the nutrient, making their consumption insufficient to meet the minimum daily requirements. Therefore, the aim of this study was to evaluate agronomic biofortification with zinc in curly lettuce cultivars. The experiment was carried out at the Universidade Federal de Uberlândia - Monte Carmelo Campus, using a complete randomized block design in a 4 × 5 factorial scheme with four replications. The factors consisted of four curly lettuce cultivars (Brida, Isabela, Thais, and Vanda) and five doses of leaf zinc (0, 400, 800, 1200 and 1600 g ha-1 of Zn). The following traits were evaluated: zinc leaf content, plant height, SPAD index, total fresh mass, stem diameter, head diameter, number of leaves per plant, and estimated average yield. Data were subjected to analysis of variance by the F test (? = 0.05) and means were compared by Tukey test at 5% probability and regression analyzes. According to the results obtained, the cultivar Thais can be considered the lettuce with highest leaf zinc content and the most biofortified. It is advisable to use 700 g ha-1 of leaf zinc to obtain biofortified lettuce with increased yield.