IMPROVING TOLERANCE OF SUNFLOWER AND SAFFLOWER DURING GROWTH STAGES TO SALINITY THROUGH FOLIAR SPRAY OF NUTRIENT SOLUTIONS

Abstract

The effect of salinity and foliar application of nutrient solutions on sunflower and safflower in vegetative and reproductive phases of the growth were investigated in Biosaline Research Field, University of Karachi, Pakistan. The seeds were sown in pots under non saline condition and saline water irrigation was started at three leaf stage after germination. Different concentration of saline water were made by dissolving 3g and 6g sea salt per litre of tap water, equivalent to an EC of 4.8 and 8.6 dS/m respectively. Nutrient solution (KNO3, H3BO3, Fe-EDTA or its mixture) was sprayed thrice, i.e., 45, 75 and 95 days after planting. KNO3 was given @ 250ppm and other H3BO3and Fe-EDTA was given @ 5ppm. Salinity caused a significant reduction in nutrient uptake, height, biomass and yield of both sunflower and safflower. Foliar application of macro and micronutrients (i.e.KNO3, H3BO3, Fe-EDTA and mixture of KNO3+ H3BO3+Fe-EDTA) partially minimized the salt induced deficiency and showed significant increase in height, fresh and dry biomass, number and weight of seeds, and amount of oil per sunflower and safflower plant irrespective to their growth under non saline or saline conditions. Among the nutrient solutions, mixture of KNO3+ H3BO3+Fe-EDTA seemed to be the most effective followed by H3BO3 and FeEDTA. These results suggested that foliar application of nutrients could be used to improve plant tolerance to salinity by alleviating the adverse effects of salinity on growth and reproductive yield.