The effect of nitrogen fertilizer and bush density on seed yield and yield components of Azargol sunflower cultivar in Takestan region, Iran

In order to evaluat the effect of different levels of N and plant densities on seed yield and yield components of Azargol sunflower cultivar an experiment was conducted in the factorial based on randomized complete block design with four replications and treatments in the research farm of agricultural departmeant of Islamic Azad university Takestan branch during 005-006. The factors of the experiment were four N fertilizer levels including 50, 00, 50, and 00 kg/ha orea manure, and three levels of bush densities (5.5, 6.6 and 8. plant/m). Results showed significant effect of different levels of N on most studied traits. Bush height, grain yield, capitulum and stem diameters, thousand seed weight, and number of grain per capitulum were increased at 00 kg/ha nitrogen treatment, but the oil percentage was decreased. Oil yield was also increased in higher levels of bush density and 00 kg/ha fertilizer amount due to increased seed yield. The highest oil percent was obtained at 00 kg/ha N fertilizer level. The effect of bush density was not significant on oil percentage, but on height of plant, grain yield, oil yield, stem and capitulum diameters, thousand seed weight and the number of grains per capitulum. Stem and capitulum diameters, thousand seed weight and the number of grains per capitulum were increased in lower bush densities, but oil yield, oil percentage and grain yield were decreased. According to the results, it seems that 8. bush/m and applying 00 kg/ha N amount is suitable for cultivation of Azargol variety in Takestan and similar regions.