Effect of Hydrogen Peroxide, Ascorbic Acid and Indolic-3-Butyric Acid on Root Induction and Development in Cuttings of Bougainvillea spectabilis

Bougainvillea (Bougainvilleaspectabilis) is used for planting in the landscape because of their beautiful and colorful flowers. The easiest and cheapest technique to propagate this plant is by cuttings; however the cuttings of this plant are not easily rooted and require the special treatments, including the use of auxin. For this purpose, an experiment was performed in Completely Randomized Design with 15 treatments and four replications and the characteristics such as root and shoot length, root and shoot number, root fresh and dry weight, and the rooted cuttings percent were evaluated. The results showed a statistically significant difference among the used treatments. The use of 400 mg/L indolic-3-butyric acid (IBA) for 24 hrs dipping led to improve rooting parameters particularly the rooted cuttings percent. However, the use of 1000 mg/L IBA for 20 s quick dipping also had satisfactory results, which can be introduced as a suitable treatment due to the reduction of application time and labor costs. Adding substances similar to ascorbic acid (AsAc) and hydrogen peroxide (H2O2) also improved some traits such as the root length, root fresh weight and the number of shoots. In general, the use of high concentrations of IBA (2000 mg/L), which are used by quick dipping with the use of pre-treatment with AsAc and H2O2 can lead to improve rooting traits in bougainvillea cuttings. When the cost of the plant growth regulators is important, the use of the low-concentration of IBA (400 mg/L) by long-term dipping (24 hrs) can be effective for Bougainvillea cuttings.