Response of different sunflower cultivars to various planting densities

In order to study the effect of plant density on yield and yield components of three sunflower cultivars, an experiment was conducted in 2006-07 at Cultural Experiment and Research Centre in Isfahan. A factorial layout within randomized complete block design with three replications was used. The experimental treatments were three cultivars of sunflower Sup. Armky-19 (Sup. A), S1 Re85 (SIR) and Sup. Prrog.sh-85 (Sup. P) and four plant densities (8, 10, 12, 14 plants per m(2)) in 60 cm interval rows. The results showed that the effect of plant density was significant on number of seeds per head, 1000-seed weight, grain yield, biological yield and harvest index. The effect of cultivar was significant on 1000-Seed weight, grain yield, biological yield, harvest index and oil percentage. Sup. A cultivar had obtained the highest seed yield (3383 kg/ha), biological yield and harvest index (25.64%). The 12 plants per m(2) had obtained the highest number of seeds per head, seed yield, biological yield and harvest index. Also, Sup. A cultivar with 12 plants per m2 had high oil percentage. It seems that under Isfahan condition, 12 plants per m2 with Sup. A cultivar were suitable.