Effect of salinity on uptake of micronutrients in sunflower at early vegetative stage

A pot culture experiment was conducted to study the effects of 4 different levels of salinity (EC = 1.19, 9.54, 16.48 and 22.38 mS/cm) on the uptake of micronutrients (viz., Cu, Mn, Fe and Zn) by 2 varieties of sunflower (Helianthus annuus L.) at early vegetative stage. Salinity levels were prepared by dissolving calculated amount of NaCl/sub 2/, Na/sub 2/SO/sub 4/, CaCl and MgCl/sub 2/ (4:10:5:1) in half strength Hoagland culture solution. In response to various levels of salinity, the uptake of all mentioned micronutrients of roots and shoots of sunflower exhibited significant response (p <0.05 and p <0.01) while only the response of Mn uptake in shoot was found non significant. A maximum significant uptake of Cu, Mn, Fe and Zn in shoot (19.50, 120.67, 1647.67 and 59.17 mu g/g) is obtained under highest dose of applied salinity (22.23 mS/cm) whereas with the exception of Zn, a maximum significant uptake of Cu (25.67 mu g/g), Mn (144.87 mug/g), and Fe (5837.5 mu g/g) in root as well in highest dose of salinity was observed. With reference to ratio of Fe and Zn uptake in root and shoot, variety DO 730 responded well than variety DO 728. Results on the bases of grand sum values depicted 20.38 and 69.33% decrease in uptake of Cu and Fe, but 7.65 and 18.37% increase in uptake of Mn and Zn in shoot over root in both the varieties, respectively was observed. (author)