Benzyl adenine, indole acetic acid and gibberellic acid at different concentrations were sprayed to study their effects on growth, chemical components and volatile oils of sweet basil in 2018 and 2019 seasons
Plant height, number of leaves/plant, average leaf area, and herb fresh and dry weights/plant greatly improved with the applied treatments especially with IAA treatments followed by GA3 treatments. However, the number of lateral branches/plant and stem diameter were increased with BA treatments especially with 10 ppm than 5 ppm. Generally, the second cut was superior in the studied vegetative growth parameters than the first cut.
The highest values of N, P, K, Fe, and Mn were recorded with BA at 10 ppm, whereas higher Zn values were recorded with BA at 5 ppm. Active ingredients including total phenols, total flavones, total chlorophyll, and L- ascorbic acid greatly increased with IAA at 50 or 100 than the other treatments or the control. However, volatile oil percentage and volatile oil content/plant were high in IAA at 50 or 100 ppm followed by GA3 at 200 ppm. The second cut was superior to the first cut in promoting volatile oil percentage and volatile oil content/plant in both studied seasons. The main components in volatile oil were 1,8-cineole, linalool, á-trans-bergamotene, germacrene D and á-muurolol. The highest values of linalool, the main component in the volatile oil of sweet basil (50.90%) was recorded by IAA at 100 ppm.