Iodine is an essential element for human health. Biofortification of vegetables by application of iodine-enriched fertilizers may help prevent iodine deficiency disorders.
In a trial with cucumber, tomato (cherry- and round type), and sweet pepper, grown in rockwool in a closed growing system with re-use of drainage water, iodine was applied as IO3 - - (Iodate) at a level of 0, 12.5 and 125 ppm I of the total fertilisers. Average concentrations for the three Iodine (I) levels were 5, 23.4 and 148 ppm in the nutrient solution, and 9.1, 38.9 and 171.8 ppm in the drainage. Iodine concentrations in plant material strongly correlated with Iodine supply. The majority of the Iodine was detected in vegetative parts. Average concentrations in fruits (mg I/kg fresh weight) for the 12.5 and the 125 ppm level were: 0.02 and 0.12 (cucumber), 0.01 and 0.04 (sweet pepper), 0.01 and 0.05 (round tomato), 0.03 and 0.12 (cherry tomato), respectively. Total biomass, yield and fruit quality were not affected by Iodate application.
The outcomes demonstrate that a portion of 80 grams of these fruitingvegetables, grown with fertilizers containing 125 mg I/kg fertilizers, constitutes 3-10 μg of iodine intake, i.e., 2-7% of the daily iodine requirement for an adult.