Effect of different gibberellic acid (ga3) doses on lavandula(Lavandula angustifolia Mill) essential oil content and components

This study was carried out during flowering season of 2017 to determine the most suitable harvest time after GA3 treatment that results in significant improvement of essential oil contents and components of lavender (Lavandula angustifolia Mill.). The experiment was carried out by applying control treatment, 200, 400 and 600 mg/l GA3 followed by harvest of flowers giving an interval of 24, 30, 36, 48, 54, 60, 72, 78 and 84 hours after spray (9 harvest times). The study was conducted using split plots randomized complete block design with 3 replications. Essential oils; Water-vapor distillation method was used by the clevenger apparatus and the components were determined by GC-MS. The results of the study showed that the amount of essential oil in lavender flowers ranged 6,20-8,20%. The highest amount of essential oil was obtained from the flowers that were sprayed 400 mg/l GA3 and harvested after 54 hours of spray. More than 50 components were identified, the most important among those were linalool, terpinene-4-ol, camphor, borneol, 1,8-cineole and lavandulol. It was concluded that the components affecting the quality of essential oil react differently depending on the doses of GA3 and the harvest times. The amount of linalool from the essential oil components ranged 34,49%-38,75%. The results depict possibility to change the amount of specific intended essential oil components depending on the harvest time. As a result; 400 mg/l GA3 was applied to obtain a high rate of essential oil. The results emphasize harvest after 48 hours in the morning after application of GA3.