Preliminary evaluation of the influence of soil fertilization and foliar nutrition with iodine on the efficiency of iodine biofortification and chemical composition of lettuce
Wydanie: 4 / 2011
Kategorie: Food science , Horticulture and forestry
According to the World Health Organization, consumption of table salt(being a major carrier of iodine in human diet) should be reduced of 50%. Vegetables biofortified with iodine can become an alternative source of this element for humans. Agronomic recommendations with reference to biofortification have to be developed, including the evaluation of side-effects associated with iodine application to plants. Iodine is not an essential element for plants and hence its effect on crops has not yet been diagnosed. The aim of the study has been to assess the influence of soil fertilization with KI and foliar application of KIO3 on the success of iodine biofortification as well as the mineral composition of lettuce. Lettuce cv. Melodion F1 was cultivated in a field experiment in 2008-2009. Combinations with different soil fertilization and foliar nutrition with iodine were distinguished in the research including: control (without iodine application), three combinations with presowing soil fertilization of iodine (in the form of KI) in doses of 0.5, 1.0 and 2.0 kg I ha-1 as well three combinations with four applications of foliar nutrition with iodine solution (as KIO3) in the concentration of: 0.0005%, 0.005% and 0.05% after using 1000 dm3 of working solution per 1 ha so that the following amounts of iodine were applied: 0.02, 0.2 and 2.0 kg I ha-1, respectively. In lettuce heads, the iodine content as well as the content of: P, K, Mg, Ca, S, Na, B, Cu, Fe, Mn, Zn, Mo, Al, Cd and Pb were determined using the ICP-OES technique, while N-total was assayed by Kjeldahl method. In comparison to the control, only foliar nutrition with 0.05% solution of iodine significantly improved accumulation of this element in lettuce. At the same time, a lower level of nitrogen nutrition was observed in plants from this combination. A significant increase in the N-total content was found only in lettuce plants fed with 2.0 kg I ha-1 dose of KI. In reference to the control, both foliar and soil application of iodine contributed to a higher content of K, Mg, Ca, Mn and Cd as well as a decreased level of P, Cu and Zn in lettuce. Doses, forms and application methods of iodine were found to have produced diverse effects on the content of S, Na, B, Fe, Mo, Al and Pb in lettuce plants.
Smoleń S., Rożek S., Ledwożyw-Smoleń I., Strzetelski P. 2011. Preliminary evaluation of the influence of soil fertilization and foliar nutrition with iodine on the efficiency of iodine biofortification and chemical composition of lettuce. J. Elem. 16/4: 613-622. DOI - 10.5601/jelem.2011.16.4.10.
Słowa kluczowe:biofortification, iodine, mineral composition, lettuce