Field experiment was conducted at Palatoo Research Farm, Amir Muhammad Khan Campus Mardan, The University of Agriculture Peshawar-Pakistan, during spring 2018. The experimental design was randomized complete block with split plot arrangement having three replications. The treatments were comprised of five sowing dates (March 3^rd, 10^th, 17^th, 24^th and 31^st) allotted to main plot and four different hybrids sunflower cv. (Hysun-33, Agsun-8251, S-278 and 5551-Agricol) allotted to sub-plot. Effects showed that sowing dates significantly affected yield and yield components of sunflower hybrids except days to emergence and physiological maturity. Among different sowing timings, March3^rdenhanced plant height (240.40 cm),early maturity (103), head diameter (18 cm), biological yield (8380 kg ha^-1), seed weight head^-1 (55.70 g), number of seedshead^-1(1087), 1000-seed weight (52.23 g), seed yield (2318 kg ha^-1), oil content (36 %) and oil yield (848kg ha^-1). However, delay in sowing timing(March 31^st)reduced the plant height (231cm), head diameter (16.45 cm),biological yield (7781 kg ha^-1),seed weight head^-1 (50 g), number of seeds head^-1 (992), 1000-seed weight (48 g), seed yield (2062 kg ha^-1), oil content (26.25 %) and oil yield (542 kg ha^-1). Among different hybrids Hysun-33 produced tallest plants (238 cm),larger head diameter (18cm), higher biological yield (8256 kg ha^-1), heavier achene’s weight head^-1 (54.70 g), moreseedshead^-1 (1102), maximum seed yield (2289 kg ha^-1), oil content (33.80 %) and oil yield (779 kg ha^-1). Interaction between sowing dates and sunflower hybrids was found significant for seed weight head^-1 and thousand seed weight (g).It was concluded from the study that sunflower hybrid Hyson-33seeded on March 3^rdshowed maximum yield and yield components, therefore recommended under the agro-ecological condition of Mardan region.

Keywords: Sowing timing, Sunflower hybrids, Sunflower yield,