162 J.E. FAUST, J.M. DOLE, AND R.G. LOPEZ
sensitive to storage, low PPF (10μmol⋅m−^2 ⋅s−^1 ) during 3◦C storage can
greatly enhance cutting quality.
VI. FUTURE DIRECTIONS
A. Automation
Stock-plant production and cutting propagation require labor-intensive
production methods; thus, there is considerable opportunity for auto-
mated systems to reduce production costs. Mechanical shearing pro-
vides the most obvious potential for reducing labor during stock-plant
production. However, the challenges for mechanical shearing include
the increased risk for spreading pathogens from one plant to another,
so this technique tends to be limited to species that are resistant to
high-risk viral and bacterial pathogens, such as poinsettia. Although
even with poinsettia production, mechanical shearing is limited to
highly stable cultivars that do not readily mutate when axillary buds
are wounded during the shearing process.
The variation in growth habit amongst floriculture species prohibits
the possibility of designing a universal cutting-harvest system. The pro-
cess of shearing is limited to species that produce upright shoots that
develop at the top of the stock-plant canopy. Chrysanthemum fits this
model and is the most likely candidate for development of automation
systems.
The prototype for mechanical shearing is currently used for miniature
rose production where shearing is used to pinch the plants that will
eventually be sold as flowering potted plants. In this system, shearers
pass over the crops, and the shorn shoots are captured on a conveyor
belt and collected for manual processing of the shoots into single-node
cuttings that are propagated to start the next crop.
Variation amongst the large variety of species and cultivars used in
the floriculture industry has limited the use of automation. So for now,
most businesses seek out low-wage countries for stock-plant produc-
tion rather than aggressively pursue automation. In the near future,
automation systems for stock-plant production will be limited to high-
volume, low-pathogen-risk species that possess an upright stem orien-
tation, such as chrysanthemum and poinsettia.
On the propagation end, the major potential automation possibili-
ties focus on the labor-intensive process of “sticking,” or inserting the
cutting into the propagation medium. Robotics are currently in use for