Responses of seed priming with gibberellic acid on yield and oil quality of sunflower (Helianthus annus L.)

Surface sterilized seeds sunflower (Helianthus annus L.) were soaked in 0, 10⁻⁷, 10⁻⁵ and 10⁻³M aqueous solution of gibberellic acid (GA) for 4, 8, 12 and 16 hours (h) and sown in pots filled with 5 kg homogenous mixture of soil and farmyard manure in the ratio of 4:1. The plants were sampled at harvest for analysis of head diameter, seeds per head, 1000-seed weight, seed yield per plant, biological yield per plant, harvest index (HI), oil content and oil yield per plant, acid value, iodine value and saponification value at harvest. All attributes were found to be significantly enhanced by the GA seed priming with maximum stimulation followed by a 8 h soaking treatment with 10⁻⁵MGA. Moreover, the most of the attributes were stimulated by 70%, 123.49%, 44.76%, 41.38% and 14.93%, 63.34%, 111.76% and 1.64% over the control except the 1000-seed weight, biological yield per plant and iodine value.