- THE FLORICULTURE VEGETATIVE CUTTING INDUSTRY 161
requirements and duration of time in propagation and then position
similar performing species and cultivars next to one another in the prop-
agation area.
D. Cut Flowers
Three of the most important cut flower species, chrysanthemum, car-
nation, andRosa(roses), are cutting propagated. Terminal cuttings are
used for chrysanthemums and carnations. For cut roses, “stenting” is
most commonly used in which a leaf and bud of the desired scion is
grafted to an unrooted stem cutting of the desired rootstock. [The word
“stenting” is a contraction of the Dutch words “stekken” (to make a cut-
ting) and “enten” (to graft).] The graft union forms at the same time that
the rootstock forms roots, which is about 3 weeks.
As with geranium, chrysanthemums are susceptible to a number of
diseases that can be transmitted through propagation. Thus, chrysanthe-
mum stock plants should be generated from virus- and culture-indexed
plants, which are maintained through a rigid clean stock program.
As with poinsettias, chrysanthemum stock plants must be maintained
under long days (short nights) to allow continued vegetative develop-
ment and prevent flower initiation and development. However, if stock
plants are continually kept under long days, flower initiation may still
occur, which results in the formation of “crown buds”. These are ter-
minal flower buds that cease to develop into normal flowers. For this
reason, stock plants must be renewed frequently, up to four times a
year depending on the cultivar grown. Old shoots with a large number
of leaves are more likely to produce crown buds than younger shoots,
so frequent pinching or cutting harvest will prevent crown-bud forma-
tion. High productions temperatures (> 25 ◦C) and weekly application of
ethephon are two techniques that are used to inhibit flower initiation
under non-inductive photoperiods.
Unlike geraniums or poinsettias, production of cuttings for cut-flower
production takes place year-round due to continuous production of cut
flowers. Terminal cuttings 2.5–5.0 cm long are harvested and easily form
roots within 1–2 weeks. Chrysanthemum cuttings are quite durable and
can be propagated under a variety of systems, including mist, fog, tents,
and directly under plastics sheets or a spunbond polyester material.
If not propagated immediately, chrysanthemum cuttings are best
stored at temperatures as low as 0–1◦C (Rajapakse and Kelly 1995;
Rajapakse et al. 1996). Chrysanthemum cuttings generally tolerate
storage well, and some cultivars can be stored for up to 6 weeks at
0–3◦C (Druege et al. 2000). For those chrysanthemum cultivars that are