Relationship between agronomic characteristics and plant density in dual purpose oil-confectionery type sunflower

To study the effect of row spacing and plant density on agronomic traits of dual purpose sunflower; cultivar Lakomka two years' study from 2014 was carried out as a factorial experiment based on RCB design with four replications in Khoy. The experimental treatments included row spacing at two levels (60 and 75 cm) and five plant densities (30, 45, 60, 75 and 90 thousands P ha-1). According to the results there were no significant difference between 60 and 75 cm row spacing for any of the studied traits; however plant density had significant effect on all of the traits. Phenological stages accelerated and head diameter decreased but plant height and oil content increased as plant density increased. Seed weight decreased from115 g to 84 g while oil content increased from 36% to 39% as plant density increased from 30 to 90000 P.ha-1. The highest seed and oil yields (4132 and 1611 kg ha-1) were observed in plant density of 75000 P.ha-1. The regression analyses revealed that oil content, plant height and seed number, are the most effective traits for predictor of oil yield. The results of this study indicated that plant densities of 75 and 45000 P.ha-1 are optimum densities for production of cultivar Lakomka with higher oil yield and as confectionary use in Khoy, West Azarbaijan.