Abstract

This research was conducted in plastic house that belong to the Nursery of Duhok university located on the Zanko campus between the months of February to June, 2022.To study the impact of various Indole Butyric Acid concentrations (IBA) at (0, 1500, 3000 and 4500) mg L-1 on the capacity of hard wood stem cuttings to root of four different cultivars of Bougainvillea includes: Flame, Ambiance, Imperial Delight and Lady Marry Baring. The results indicate that the growth is affected by cultivars and the greatly elevated majority of growth characteristics may be the result of Flame cultivars cuttings compared with other cultivars. Among all IBA concentrations the maximum rooting percentage (62.86%), roots number per cutting (14.81 root cutting-1), longest root (12.50 cm), stems number per cutting (2.00 stem cutting-1), longest shoot length (18.06 cm) and plant weight (14.04 g) were observed under 3000 mg L-1 IBA concentration. In contrast, the combination of different cultivars and varying IBA concentrations resulted in a significant increase across all parameters. Notably, the highest rooting percentages of 86.60% and 86.13% were showed in the cuttings of Imperial Delight cultivars treated with IBA concentrations of 3000, 4500 mg L-1, respectively.