The Effect of Natural and Chemical Compounds on Rooting Traits of Bougainvillea (Bougainvillea spectabilis L.)

Bougainvillea (Bougainvillea spectabilis L.) is an evergreen, difficult-to-root ornamental plant with plentiful applications in green spaces. One of the effective methods in plants propagation is the use of hormonal compounds such as indole butyric acid. Despite the positive effects of these hormones on rooting process, their chemical nature causing environmental risks. Thus, the use of alternative natural compounds with favorable influence to create environmental health and living creatures is important. This experiment was conducted to examine the impact of natural carbohydrate compounds and chemical hormonal compounds on the rooting traits of bougainvillea in the research greenhouse of Gorgan Agricultural Research Center and in the Horticulture Laboratory of Department of Plant Production, Gorgan University of Agriculture Science and Natural Resources, Iran in 2015-2016. The study was based on a Completely Randomized Design with six treatments (indole butyric acid (IBA), aspirin pills, LD pills, natural honey, grape syrup, and gum Arabic), each at four rates, and a control with five replications, each one including five cuttings. The natural and chemical treatments influenced rooting traits including rooting percentage, the number of primary and secondary roots, primary root length, root fresh and dry weight, and survival rate of the cuttings significantly at the 1% level. The treatments of 4000 ppm IBA and 10% grape syrup exhibited significant differences with other studied treatments, control, and displayed the best quantity and quality of the rooting. However, 20% gum Arabic and honey, 4 pills L-1 (320 mg L-1) aspirin, and 4 pills L-1 (0.72 mg L-1) LD were related to the best rooting of the cuttings as compared to other treatments and control. Given the effectiveness of natural compounds like grape syrup on the rooting of bougainvillea cuttings, because of the natural and non-chemical nature, their cost-effectiveness, organic and friendly environmentally it is recommended to use them.