Improvement of Seed Yield, its Components and Oil Content of Sunflower (Helianthus annuus L.) by Applications of Chemical and Organic Fertilizers

To evaluate the effect of different levels of chemical and organic fertilizers on seed yield, its components and oil content of sunflower (Hybrid Iroflor), a factorial experiment based on randomized complete blocks design (RCBD) with 12 treatment and 4 replications was carried out at the Faculty of Agriculture, University of Maragheh during 2014 growing season. The first factor consisted of 3 levels of chemical fertilizer (C0: without using any fertilizer, C1: application of urea at the rate of 150 kg.ha-1 and C2:application of 75 kg.ha-1 urea 50 kg.ha-1 super phosphate triple) and the second factor comprised of organic manure applications (O) with 4 levels (O0: without organic fertilizer, O1:animal manure application at the rate of 40 t.ha-1, O2: poultry manure application at the rate of 30 t.ha-1 and O3: %50 poultry manure %50 animal manure. Results showed that the highest chlorophyll index belonged to %50 nitrogen 50% phosphorus plus poultry manure and nitrogen fertilizer plus poultry manure treatment combinations respectively. Applications of 75 kg N ha-1 50 kg P ha-1 and %50 poultry manure %50 animal manure treatment combination, resulted in grain yield increase by %42.02 as compared to the application of 75 kg N ha-1 50 kg P ha-1. Maximum kernel number per head was produced by interaction effect of chemical nitrogen fertilizer (150 kg N ha-1) animal manure (40 t.ha-1). Biological yield and harvest index were increased by %22.9 and %15.98 respectively, as compared to control and application of %50 poultry manure %50 animal manure. Highest percentage of grain oil (52.45%) was obtained by applications of 15 t.ha-1 poultry manure 20 t.ha-1 of animal manure, as compared to the control (30.13 percent). The highest oil yield (1784.57 kg.ha-1) was also belonged combined application of 75 kg N ha-1 50 kg P ha-1 and 15 t.ha-1 poultry manure 20 t.ha-1 animal manure. Thus, integrated application of organic and chemical fertilizers (75 kg N ha-1 50 kg P ha-1 and 15 t.ha-1 poultry manure 20 t.ha-1 animal manure) improved both grain yield and its oil content of sunflower more than their individual applications.