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Copyright 2005, Board of Trustees, University
S GULF COAST RESEARCH & EDUCATION CENTER
.... IFAS, UNIVERSITY OF FLORIDA
5007-60TH Street East
Bradenton, FL 34203
Bradenton GCREC Research Report BRA1985-17 May 1983
GUIDELINES FOR PRODUCTION OF EPISCIA
B. K. Harbaugh, J. F. Price and W. E. Waters
Many floricultural crops are not suited for production in the summer months
because. of high temperature and humidity in greenhouses. Episcia cupreata,
or flame violets, are an exception to the rule. They thrive in high tempera-,
tures that usually.cause scheduling and flower quality problems with traditional
flowering greenhouse pot plants. The following guidelines summarize experiments
performed on Episcia over several years at the Gulf Coast Research and
.. Education. Center, Bradenton,. FL.
Episcia--are subject -to -chilling injury when exposed to 50F for only a
few hours. Chilling injury can be detected when water-soaked areas appear
on leaves .These areas become, brown or black, depending on the level and
duration of the cold temperature, and- the tissue dies within several days.
Colder temperatures or longer durations will kill the, plant. Heating require-
ments make Episcia unacceptable for production in most of the continental
US, .except during the summer.
Optimum growing temperatures range from 700 to 90* F.. This range is relatively
easy to achieve because shade is necessary to provide optimum.light intensity,
and this helps to-reduce greenhouse temperatures during hot summer months.
The optimum light intensity for Episcia production is 1,500 to 2,000 footcandles
(17 to 22 klux). Lower light intensity causes excessive stem elongation
(spindly plants), fewer flowers, and diminished general quality and appearance
of plants. Higher light intensity results in stunted plants with bronze
leaves.and few flowers and stolons.
Several media, rates and types of microelements, and media pH's were evaluated.
Results indicate that most amended commercial media would be satisfactory
for growing Episcia. Our media was a volume- mix of 5 Florida peat, 3 builders
sand, 3 vermiculite and 1 perlite amended with 5 pounds per cubic yard
dolomite, 3 pounds per cubic yard hydrated lime,. 2? pounds per cubic yard
single superphosphate and 2 pounds per cubic yard Perk (a micro element
mix). Any medium giving similar physical properties and containing calcium,
magnesium, phosphorus and .microelements should be satisfactory.
Nitrogen and potassium requirements with amended soil mixes as given abovc;
can be satisfied with a 200 to 250 ppm nitrogen and 150 ppm potassium solution
applied at a rate of 50 milliliters (1.7 ounces) per 4-inch pot per week.
Thus, a balanced fertilizer, such as 10s0:10 o:. 20:0:20, would provi.,
an adequate nitrogen:potassium ratio, since potassium is 83% of the K20
represented on fertilizer labels.
Fertilizer concentrations commonly used for many ::lozicultural crops, such
as chrysanthemum and poinsettia, cause salt injury ta Episcia, Although
some cultivars tolerate fertilizer rates higher tha: 200 ppm nitrogen,
many cannot, especially in the early propagation stige. Salt injury symptoms
first appear on newly expanding leaves of the terminal shcet. These be-.-me
water-soaked,' then necrotic and finally cease rowing. Other symptoias
include a marginal leaf necrosis that appears similar to chIlling injury.
The necrosis from salt injury is distinguished. -rom chilliLi injury in
that the latter.develops randomly over the plant or leaf. We believe that
salt injury has often been erroneously diagnosed as a disease problem.
As the terminal shoot dies from salt injury, the p.ant appears to have
a black-stem rot.
Plantlets produced on stolons are used for propagation. The older plantlets
are the largest.. successive, younger plantlets, forming on the stolon are
progressively.. smaller. The size differential affects the length of time
needed to produce marketable plants. Episcia grown in 4-inch pots are
marketable when the plants are 8 to 10 inches in diameter (2 to 2? times
the pot diameter). Our results show that plantlets forced in 4-inch pots
are marketable in 4 to 6 weeks with initial plantlet sizes ranging from
41 to 5 inches in diameter, 6 to 7 weeks with 3h to 4k-inch diameter plantlets
or 8 to 9 weeks with 2- to 3-inch diameter plantlets. An additional 10
days to 2 weeks is necessary if unrooted plantlets are used.
Unrooted plantlets can be potted directly into 4-inch pots, or they can
be rooted in a propagation bench and then transplanted. Sand, vermiculite.
light soils or artificial soil mixes work fine for propagation, but -it
is critical to use a propagation medium that is low in soluble salts.
The misting cycle is not critical. If humidity is -low, a propagation house
with 10 seconds of mist every 30 minutes is satisfactory. Rooting is rapid
during summer months (high temperatures of 700 to 90 F) and requires 1
to 2 weeks depending on the age and size of plantlets (older plants root
Mealybugs are a major problem on Episcia, but several insecticides can
control them. Mealybugs don't fly, and once the infestation is controlled,
proper sanitation should reduce the need for further insecticides.
In our experiments, Orthene 75 SP (acephate) and Temik 10G (aldicarb) did
not damage flowers on 'Acajou' and 'Frosty' cultivars. Open flowers treated'
with Ethion 4EC (ethion), Metasystox-R 2 EC (oxydemeton-methyl), Vydatl
2L (Oxamyl) and Thiodan 3EC endosulfann) were spotted, but none of thC
insecticides caused phytotoxicity on foliage. Flower buds were unaffected,
and new flowers developed following insecticide treatment.
Southern armyworms were occasionally found feeding on Episcia foliage.
However, they were controlled with Lannate 90 SP (methomyl).
The guidelines presented so far were developed for production of Episcia
in 4-inch pots, which make very attractive potted plants suitable for mass
marketing as flowering houseplants. Episcia also look excellent in hanging
baskets with the stolons draping over the side of the basket. Two plants
in a 6-inch diameter basket, three in an 8-inch basket or four in a 10-inch
basket will grow similarly to Episcia grown in 4-inch pots. To grow multiple
plants in a pot, increase the volume of fertilizer to 50 milliliters of
solution per plant per week. For example, use 100 milliliters for a 6-inch
basket with two plants, rather than 50 milliliters for a 4-inch pot with
Other production requirements are the same for plants produced in hanging
baskets as for those in 4-inch pots.
Since Episcia can only survive in warm temperature, care tags advising
consumers of the temperature requirement are very important and should
be included when selling the plants. Also, shipping and retail outlet
personnel must be informed that chilling injury to the foliage or the entire
plant will occur at 50*F or below. The potential acceptance of Episcia
will depend on how plants are handled in transit as well as growers following
proper cultural practices.
Episcia may find a niche in floricultural operations that produce crops
year-round. Episcia plants offer consumers a variety in their choice of
indoor plants with long-lasting color, and give growers a crop they can
easily produce during summer months.