Response of Growth, Yield and Yield Components of two Sunflower Varieties (Helianthus annuus L.) to Nitrogen Fertilization

Abstract

A field study was conducted at spring 2013 in the experimental farm of the Faculty ofAgricultural Science, University of Sulaimany at Bakrajo, to evaluate the response ofsome growth characters, yield and yield components of two varieties Flame and Sirenaand three Nitrogen fertilization on growth and yield sunflower (Helianthus annaus L.).The experiment comprised of two varieties of sunflower (Flame and Sirena) andNitrogen fertilization levels (0, 100 and 200) Kg (urea) ha-1. Arranged as Split-Plot inRandomized Completely Block Design with three replications. performances in termof plant height, leaves number and stem diameter were evaluated. The importantcharacter of yield, yield components and growth were also evaluated. The Nitrogenfertilizer levels were implemented in the main plots and varieties implemented in thesub-plots. The results showed no significant differences between varieties in growthcharacters with exception of stem diameter, while it was found to be significant on allyield characters with exception of disk diameter, there were no significant differencesof nitrogen levels on growth characters with exception of number of leaves plant -1,while it was found to be highly significant on all yield characters. The effect ofinteraction between varieties and Nitrogen levels were no significant for all growthcharacters, yield and yield components continue.The highest percentage of oil represented in the variety (Flame) under the treatment ofcontrol.