EFFECT OF FOLIAR-APPLIED BORON AND MANGANESE ON GROWTH AND BIOCHEMICAL ACTIVITIES IN SUNFLOWER UNDER SALINE CONDITIONS

Experiments were conducted to assess whether exogenous application of some essential micronutrients (B and Mn) through foliar spray could ameliorate the adverse effects of salt stress on growth and biochemical activities of sunflower plants. Sunflower (NuSun 636 cv) were grown under normal and different saline conditions, created through 0.4% (ECiw 6.1 dS/m) and 0.8% (ECiw 10.8dS/m) of sea salt irrigation. Salinity was found to cause a significant reduction at all the vegetative and reproductive growth parameters. Salt stress showed inhibition in biochemical activities such as amount of protein, nucleoprotein and Hill reaction in sunflower leaves. Foliar applications of B through H3BO3 and Mn through MnCl2 and their mixture were found to improve all the studied growth parameters and biochemical activities of sunflower plant irrespective to their growth under non-saline or saline conditions. The growth and yield component as a result of the mixture of foliar spray was higher than spray of single element. Their spray appeared to ameliorate the toxic effects of excessive sodium present in growing medium which is reflected by producing economically feasible yield even beyond the threshold value of salinity (ECe 5.5ds/m).