Effects of nitrogen doses on growth and some nutrient element uptake of sunflower (Helianthus Annuus L.) hybrids

Abstract

Abstract. Sunflower (Helianthus annuus L.) is known as one of the most important and preferred vegetable oil producing plants. In recent years, new cultivars with high oleic acid contents have been developed because of their health effects, extended frying and shelf life. On the other hand, nutrition of the plants is important for healthy growth, high yield, and oil quality and their nutrient needs may differ between the plant species and varieties. We aimed to determine the effects of increasing application doses of nitrogen (N) (0, 16, 32, 48, and 64 mg.kg-1 N) on growth and on some nutrient element uptake of four sunflower hybrids and compare the nutritional differences of linoleic (ESNovamis CL, and LG 5542 CL) and high-oleic (Oliva CL and ESGrafic CL) type sunflower hybrids in a greenhouse. The experiment was conducted in randomized factorial design with three replicates. Increasing doses of N effected the dry matter and nutrient uptake of sunflower hybrids significantly (p<0.01). Increasing doses of N elevated the dry weight, N, phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), zinc (Zn), copper (Cu), manganese (Mn) and boron (B) uptake of all tested sunflower hybrids. The increases were found maximum at 32 mg.kg-1 N dose. Significant differences were also established between the hybrids. Among the tested hybrids, ESGrafic CL a high oleic type sunflower has higher nutrient uptake capacity so much more nutrients might be supplied to this new generation sunflower hybrids according to the soil and plant analysis results.