Effect of Irrigation Water Containing Iodine on Plant Physiological Processes and Elemental Concentrations of Cabbage (Brassica oleracea L. var. capitata L.) and Tomato (Solanum lycopersicum L.) Cultivated in Different Soils

Abstract

Iodine uptake and translocation was studied in cabbage and tomato cultivated on different soil types (sand, sandy silt, silt) by applying irrigation water containing iodine at concentrations of 0.1 and 0.5 mg/L. Iodine treatment at the concentrations applied did not significantly influence the photosynthetic efficiency and chlorophyll concentration of cabbage and tomato leaves. The growth of cabbage leaves cultivated on sand and sandy silt soil with iodine treatment was slightly stimulated, while, on silt soil, it remained unchanged; for tomato plant parts, independent of the soil-type, the dry mass values remained constant. It can be concluded that iodine treatment had no negative effect on the physiological characteristic of cabbage and tomato plants. Applying 0.5 mg/L in the irrigation water, the highest biofortification with iodine was achieved in plants cultivated in sandy soil and the iodine concentration calculated in the dry matter amounted to 10 and 3.6 mg/kg in the leaves and fruits of cabbage and tomato, respectively. Considering the iodine and moisture content of cabbage leaves and tomato fruits, the consumption of 100 g of fresh vegetable would cover about 80% and 15% of the recommended iodine intake, respectively. The presence of iodine resulted in a reduction in Fe and P concentrations in tomato fruits independent of the soil-type; however, the concentration of Mg, Cu, Mn, Zn, and B remained practically unchanged. However, for cabbage, no similar trend for Fe and P was observed.