Effect of Delayed Planting Date on Phenological Traits, Grain Yield, and Some Fatty Acids of New Sunflower Hybrids

In order to evaluate the planting date delay on phenological traits, yield components, grain yield, and linoleic and linolenic fatty acids of new sunflower hybrids, an experiment has been conducted as split plot in a randomized, completely block design, with four replicates at the field of oilseed section of seed and plant Improvement during 2014-2016 growing season. The treatments include seven sunflower hybrids (Barzegar, Farrokh, Haysan 36, Qasem, Shams, Azargol, and Haysan 25) on three planting dates (15 days after harvest of autumn (wheat), July 1, July 15, and July 30, respectively). The experimental results show significant effects of planting date on all traits except number of seeds per head and linolenic acid at the level of 1% and on the percentage of oil and linoleic acid at the level of 5%. The studied hybrids are significantly different in all traits except linoleic and linolenic fatty acids. The latest experimental hybrids include Barzegar and Azargol hybrids and the earliest hybrid is Farrokh. The highest grain yield is obtained from the date of the first sowing at the rate of 2840 kg / ha and in the case of delayed sowing the yield is reduced to 41%.