Texas FFA Nursery Landscape Practice Exam

Which two synthetic root-promoting chemicals are most commonly used in rooting hormones?

1. IBA and AAN

2. ISO and OSB

3. IBA and NAA

4. CCA and ACD

The correct answer is: IBA and NAA

The correct answer is based on the common use of specific synthetic root-promoting chemicals in rooting hormones. Indole-3-butyric acid (IBA) and naphthaleneacetic acid (NAA) are the two most widely recognized rooting hormones used in the horticultural industry. Both of these substances are auxins, which are plant growth regulators that play a crucial role in stimulating root development. IBA is particularly effective for promoting root growth in cuttings because it promotes root initiation and elongation, leading to a higher success rate in propagation. NAA is also used for its effectiveness and is often favored for various types of woody cuttings as it helps facilitate the rooting process. The combination of IBA and NAA provides a powerful tool for horticulturists and gardeners who are looking to propagate plants efficiently. The other options do not accurately reflect the commonly used rooting hormones; they either consist of chemicals not recognized for their root-promoting properties or contain substances that are not typically associated with rooting hormone formulations. Understanding the correct terminology and substances involved in plant propagation is essential for effectively using rooting hormones in plant care and nursery practices.