- THE FLORICULTURE VEGETATIVE CUTTING INDUSTRY 139
morning. Interestingly, lantana cuttings harvested during cool, winter
months (21/9◦C day/night) were not sensitive to chilling damage com-
pared to cuttings harvested during warm, summer months (31/20◦C
day/night), indicating that pre-acclimation might be possible. ForPlec-
tranthus coleoides, increasing storage duration from 0 to 14 d and reduc-
ing storage temperature from 12◦Cto1◦C reduced rooting percentages
(Kadner 2002). At 5 or 12◦C, over 90% of cuttings rooted after 7 d of
storage, whereas at 1◦C rooting declined below 90% after 5 d, due to
chilling damage, which appeared after 3 d of storage. At 5◦C, chilling
damage appeared after 6 d of storage. New Guinea impatiens and dou-
ble impatiens exposed to chilling temperatures, for example, 5◦C, in
the postharvest environment will exhibit leaf abscission due to ethy-
lene production (J.E. Faust, unpublished).
Cutting storage can sometimes improve subsequent rooting. Callus
formation along the base of the stem occurred during long-term hibis-
cus (Hibiscus rosa-sinensis) cutting storage (8 weeks), which enhanced
subsequent rooting (Kirk et al. 1996). Wang also noted that croton (Codi-
aeum variegatum) cuttings stored for 5–15 d at 15–30◦C had longer
roots, 4 weeks after propagation than those on unstored cuttings, indi-
cating that root initiation commenced during the storage period. Garrido
et al. (1998) noted that cold storage at 4◦C for up to 6 weeks increased
percentage of rooted cuttings rooting and decreased rooting time for
‘Solar’ carnation, but had no effect for ‘Master’ carnation. The applica-
tion of indole-3-butyric acid (IBA) to carnation cuttings prior to storage
induced callus and root formation during storage; the lower the storage
temperature, from 25◦Cto0◦C, the longer the cuttings had to be stored
to see callus or root formation (van de Pol and Vogelzang 1983). How-
ever, cuttings stored at 13◦C or higher for 9 or more days increased the
likelihood ofFusariumdevelopment later in production.
The presence of callus tissue on cuttings prior to storage can enhance
storability. Von Hentig and Knosel (1986) noted that unrooted poinset-
tia cuttings can be stored for a maximum of 10 d at 12–13◦C, whereas
callused cuttings could be stored successfully up to 4 weeks under the
same temperatures. In addition, callused cuttings have the advantage of
faster rooting than uncallused cuttings.
The role of light in storage has not been extensively studied, probably
due to the commercial impracticality of storing cuttings in a way that
they can receive light. Wang (1987) noted that the presence of light did
not improve rooting of croton cuttings after propagation. However, low-
light levels (e.g., 10μmol⋅m−^2 ⋅s−^1 ) during 3◦C storage greatly enhanced
the quality of chrysanthemum cuttings taken from cultivars that were
previously determined to be sensitive to storage, but had a limited effect
on cultivars that were tolerant of storage (Rajapakse and Kelly 1995;