EFFECT OF NITROGEN LEVELS ON YIELD, YIELD COMPONENTS AND SEED QUALITY OF SUNFLOWER HYBRIDS

Two experiments were conducted in 2001 spring and fall seasons. The first experiment was carried out at the farm of College of Agricultre/Abu-Ghraib and the second at Ishaki Research Station Baghdad. A split-plot arrangement in a randomized complete block design was used with four replications. Main plots were five levels of nitrogen (0, 120, 160, 200 and 240 kg Niha) and sub plots five sunflower hybrids (AS 6310, 44403, Golidor, Iraq flower and Eureflor). The results showed that there was a significant effect among nitrogin levels and the characters studied except oil content. Application of 240 kg N/ha gave the highest yield, yield components, oil yield and protein percentage, As an average they were 5.667 and 4.950 t/ha seed and 2.355 and 2.107 t/ha oil in spring and flail respectively. The different hybrids showed differences as regards all characters studied. The Iraq flower hybrid gave the greatest yield of seeds (4.443 and 4.504 t/ha) and oil yield (2.078 and 2.019 t/ha) In spring and fall. respectively. Interaction between seed weight and oil percentage in both seasons was significant.