Phytotoxic effects of nickel on yield and concentration of macro- and micro-nutrients in sunflower (Helianthus annuus L.) achenes

▶ Lower level of Ni had no effect on growth and sunflower achene yield, but higher Ni levels significantly reduced them. ▶ Ca, Mn and Fe concentrations in achenes increased at lower level of Ni, however, they decreased significantly at higher Ni levels. ▶ N, K, Zn, Mn and Cu concentrations in achenes decreased consistently with increase in external Ni level even at low concentration. ▶ P and Mg concentrations in achenes were not affected by Ni application.