FORTIFICATION OF SUNFLOWER PLANTS (HELIANTHUS ANNUUS L.) WITH SELENIUM

Selenium is a trace element which in small amounts is necessary for human and animal nutrition. In the organism it helps a number of antioxidant enzymes to function normally. In many parts of the world, including the Central European region, its content in agricultural products is very low. Attempts are therefore made to increase its content and cover human requirements with biologically valuable products by incorporating selenium into the system of plant nutrition. In a vegetation trial established in 2010 and 2011 we explored the effect of foliar applications of Se (IV) on achenes yields and on content of selenium in the seeds and the uptake of selenium by the sunflower stand. Solutions of sodium selenite at 0.16 and 0.5 g Se.he(-1) were applied at rates 50 and 150 g Se.ha(-1) at the beginning of elongation growth (stage R-1). Sunflower achenes yields were significantly influenced by the weather in the experimental years. In 2011 sunflower production was by 29.4% lower than in 2010. Se fortification in dose 50 g Se.ha(-1) increased sunflower achenes yield by 3.1%. The higher dose of selenium (150 g Se.ha(-1)) reduced yields by 6.8% compared with the no-fertilized treatment. Due to the effect of foliar Se nutrition the content of selenium in sunflower achenes increased highly significantly from 123 mu g.kg(-1) to 6,004 mu g.kg(-1) of achenes. The weight of 1000 achenes, oil content and content of palmitic, palmitoleic, oleic, linoleic acids were not significantly affected by selenium application. Fortification of Se increased stearic acid content from 3.16% to 3.47%.