EFFECTS OF PLANT DENSITY ON MICRONUTRIENT UPTAKE IN SUNFLOWER (Helianthus annuus L.) VARIETIES

The objective of this study was to determine the effects of plant density per unit area on micro nutrients (Iron, Copper, Zinc, Manganese and Boron) uptake of some sunflower genotypes. Three sunflower varieties (Sanay MR, Oliva CL and LG5543 CL) were used as genetic material and three different plant densities: 40800, 57100 and 95200 plants/ha (sowing spacing; 0.35 x 0.70, 0.25 x 0.70 and 0.15 x 0.70 m, respectively). Field experiments were conducted in a split plot design with three replications. According to the results, the micronutrient concentrations as well as the seed and oil yields and partly also oil content increased significantly as the plant density increased. For all analyzed micronutrients (Fe, Cu, Zn, Mn and B), the highest concentration has been obtained with 95200 plant ha-1. Micronutrient elements as well as seed and oil yields differed according to plant density and cultivars. Among the varieties, LG 5543 CL more effected by plant density had the highest micronutrient concentration, seed yield and oil yield. As a result, a high plant density (95,200 plant ha) with the highest micronutrient content and also the highest seed and oil yield could be recommended for Mediterranean environments with a semi-humid climate. However, optimum plant density was found differently according to varieties and years.