Francisco Figueroa

Rooting hormons are best to employ to estimulate cuttings to develope roots. If the Musa basjoo, or any other plant, has already its own roots, or is starting to grow them, then rooting hormons like Indolbutiric Acid, IBA, etc could cause the destruction of fine roots, these hormons although exist in the nature are fitotoxic in the concentrations we use and they are also carcinogenic, so they must be handled with protection and carefully.
By the other hand, if the rooting compound is just a rich soil with stimulants, aminoacids and nutrients for the plant, they can be of much help to stablish and increase the rootsystem when planting a plant already with roots, and foster rooting in cuttings which can root without much complications.