126 J.E. FAUST, J.M. DOLE, AND R.G. LOPEZ
industry from potential biological threats being imported from abroad.
For example, the European Union does not allow the importation of
the solanaceous species such as petunia and calibrachoa from Africa
and Central America (Official Journal of the European Communities
2000). As a result, many petunias and calibrachoa cuttings are pro-
duced in Israel for the European market. Another example is with sweet
potato (Ipomoea batatas), of which there are many ornamental culti-
vars that cannot be imported into the United States due to the threat of
sweet potato weevil (Cylas formicarius) and the sweet potato scarabee
(Euscepes postfasciatus) to the commercial sweet potato crop. Trans-
portation of sweet potato cuttings across some state lines within the
United States can also be problematic due to sweet potato weevil quar-
antine zones (National Plant Board 2015). Additionally, internationally
transported plants must undergo inspection at a port-of-entry before
shipments can be delivered. Offshore geranium-production facilities
are also inspected by the crop-protection services of the importing coun-
tries to verify that sanitation protocols are being properly implemented.
The vegetative cutting industry is now an economically important
segment of floriculture (Fig. 3.1). More than 4.3 billion cuttings are pro-
duced annually in over 400 ha of greenhouses by the 10 largest cut-
ting suppliers for the international floriculture industry (Drotleff 2014).
The most important ornamental plants include: calibrachoa (Calibra-
choa×hybrida), carnation (Dianthus caryophyllus), chrysanthemum
(Chrysanthemumspp.) New Guinea impatiens (Impatiens hawkeri),
poinsettia (Euphoria pulcherrima), petunia (Petunia×atkinsiana)and
zonal geranium (Pelargonium×hortorum) which are grown as cut flow-
ers, flowering potted plants, or bedding plants. The objective of this arti-
cle is to review the vegetative cutting industry from cutting production
on stock plants, through the postharvest environment, into propagation
which results in rooted cuttings that are that then grown into mature
plants for retail sales.
II. STOCK-PLANT PRODUCTION
Stock plants are plants that are solely grown for the production of
unrooted cuttings, the most common of which are shoot-tip cuttings.
These cuttings most often consist of 2–5 cm long stems that include the
shoot tips and several leaves. The cuttings are generally harvested on a
weekly basis from the top of the stock-plant canopy.
Single-node cuttings are often harvested for species that are vining
in habit, for example, thunbergia. For these species, the vining shoots