See this interesting comment of the document from Hartmann and Kester's Plant Propagation book:
http://aggie-horticulture.tamu.edu/faculty/davies/pdf%20stuff/ph%20final%20galley/Chap%209%20-%20M09_DAVI4493_08_SE_C09.pdf
By the way, a book of high academic level, a propagation bible!!
In the page 42 of 65 (319 of the total document):
Auxin Suppression of Bud-Break of Cuttings
Application of auxins to stem cuttings at high concentrations
can inhibit bud development, sometimes to
the point at which no shoot growth will take place even
though root formation has been adequate. Application
of auxins to root cuttings may also inhibit the initiation
and development of shoots from such root pieces.
Basally applied IBA increased rooting but inhibited
bud-break of single-node rose stem cuttings. IBA was
translocated to the upper part of the cutting, where it
inhibited bud-break and increased ethylene synthesis of
the cuttings (272).
Early bud-break and shoot growth of newly
rooted cuttings are important in the overwinter survival
of Acer, Cornus, Hamamelis, Magnolia, Prunus, and
Rhododendron (305). These species need to put on a
growth flush (after rooting but prior to winter dormancy)
so that sufficient levels of carbohydrates are
stored in the root system to ensure winter survival.
Hence, there is concern about auxin-suppressing budbreak
and growth of rooted cuttingsāand reduced