Effect of iodine containing irrigation water on plant physiological processes of bean and potato cultivated in different soils

Iodine deficiency is a well known environmental health problem in several regions of the world. Fruits and vegetables have been proven to be an effective way to increase iodine intake for humans by iodine enriched edible plants. In our study plant physiological processes of potato and bean plants cultivated on three different soils (sandy, silty sand, silty soil) applying potassium iodide containing irrigation water in concentration of 0.10 and 0.50 mg/L were investigated. After the harvest the plant parts (root, aerial parts and fruits) were dried and their mass were determined. The homogenized plant parts were mineralized by microwave-assisted acidic digestion. Iodine and essential element concentrations were measured by inductively coupled plasma mass spectrometer. In case of bean fruits the iodine addition (0.50 mg/L) resulted in considerable reduction (20-50%) of biomass, while the relative change of potato mass amounted to only -10% - +10% depending on the soil type. Results showed, that applying 0.50 mg/L iodine concentration in the irrigation water, the highest iodine concentration in edible parts of bean and potato plants were 1.6 mg/kg (silty soil) and 0.8 mg/kg (sandy soil), respectively.