Enhancement of seed germination of yarrow with gibberellic acid, potassium nitrate, scarification, or hydropriming

Poor germination and the length of time required for the growth of seedlings appropriate for planting in the farm affect the cultivation of medicinal plants such as yarrow (Achillea millefolium L). This study investigated the abilities of different concentrations of gibberellic acid (GA(3)) and potassium nitrate (KNO3), mechanical scarification, and hydropriming to improve seed germination and dormancy release in yarrow. Seeds were germinated on filter paper in Petri dishes and supplemented with 0, 100, 200, 400, or 800 mg L-1 GA(3;) 0%, 0.2%, 0.5%, 1.0%, or 2.0% w/v KNO3; 0, 24, or 48 h of hydropriming; and mechanical scarification. Seed priming with GA(3) (800 mg L-1) or 1% KNO3 at 48 h priming time improved the mean daily germination. Application of 1% KNO3 had the highest seed germination around 91%. Use of 0.5% KNO3 in 48 h priming time increased seedling length approximately 52% compared with unprimed seeds. Combinations of scarification and hydropriming increased germination. The use of priming with KNO3 at 48 h priming time was effective in improving seed germination.