Agronomic biofortification of wheat with selenium | Agronomická biofortifikácia pšenice selénom

In this study, the effect of foliar application of graduated Se rates (0.5, 1.0, 10 and 20 g Se per ha) on the winter wheat grain yield and Se accumulation in grain was investigated in the accurate field fertilization experiment. Selenium fertilization was realized individual and together with the application of liquid fertilizer DAM-390 (30 kg N per ha) in the growth stage of the 6th leaf (Zadoks=29). Applied treatments of Se fertilization did not influence the yields of grain. Both the rates of 10 and 20 g Se per ha highly significantly increased Se accumulation in grain in all experimental years. The average Se content in grain dry matter was 0.039 mg per kg under unfertilized treatment and with the Se rates of 10 g and 20 g per ha it increased to the value (at together application with nitrogen) of 0.088 and 0.145 mg per kg, respectively. The total offtake of Se by grain yield increased in the similar way. It results from the experiment that the rate of 10 g Se per ha is sufficient for achieving the required Se content in winter wheat grain. The influence of application of increasing doses of selenium (0.05 mg, 0.10 mg and 0.20 mg per kg) into soil in pot experiments, with NPK fertilization of spring wheat, on the biomass yield (grain, straw, roots) and on selenium accumulation was observed. Selenium in the form of sodium selenite (Na2SeO3.5H2O) and the NPK nutrients in the form of NH4NO3 with dolomite (LAD-27), Ca(H2PO4)2 and KCI were applied. The average two-year results showed the expected indifferent effect of increasing doses of selenium on the yield of wheat grain, straw and roots. The differentiated doses of selenium into soil caused a significant increase of selenium content in dry matter (dm) of grain, straw and roots of wheat. The highest content of selenium (0.732 mg per kg in grain, 0.227 mg per kg in straw and 1.375 mg per kg in roots dm) was determined in the variant where 0.2 mg Se per kg of soil was applied. When applying the lowest dose of selenium (0.05 mg Se per kg of soil) the content of selenium was 0.155 mg Se per kg in grain. The selenium content in individual analysed parts of wheat was increasing in the following order: straw - grain - roots.