| Material Information
||Relationships of dolomite and superphosphate to production of Calathea
||AREC-A research report
||2 p. : ; 28 cm.
||Conover, Charles Albert, 1934-
Poole, R. T ( Richard Turk )
Agricultural Research and Education Center (Apopka, Fla.)
||University of Florida, IFAS, Agricultural Research and Education Center-Apopka
||Place of Publication:
||Calathea -- Growth -- Florida ( lcsh )
Dolomite -- Testing -- Florida ( lcsh )
Superphosphates -- Testing -- Florida ( lcsh )
||government publication (state, provincial, terriorial, dependent) ( marcgt )
bibliography ( marcgt )
non-fiction ( marcgt )
||Includes bibliographical references (p. 2).
||Statement of Responsibility:
||C.A. Conover and R.T. Poole.
||AREC-Apopka research report ;
The publications in this collection do
not reflect current scientific knowledge
or recommendations. These texts
represent the historic publishing
record of the Institute for Food and
Agricultural Sciences and should be
used only to trace the historic work of
the Institute and its staff. Current IFAS
research may be found on the
Electronic Data Information Source
site maintained by the Florida
Cooperative Extension Service.
Copyright 2005, Board of Trustees, University
RELATIONSHIPS OF DOLOMITE AND SUPERPHOSPHATE TO PRODUCTION OF CALATHEA
C. A. Conover and R. T. Poolel
University of Florida, IFAS
Agricultural Research and Education ;entqreApop a nna-- D
AREC-A Research Report RH-8 -IdulviC- LIilRA
JAN 28 1985
Calathea insignis and Calathea makoyana are two of the more common
calatheas grown by the foliage industry. Howeve l[.A.6jtWiaftatiffothL
foliage plants (2), these calatheas sometimes de re- p--ei'es-with--margin 1
or tip necrosis attributed to fluoride toxicity. The appearance of symp-
toms is most often related to periods of high light and/or temperature
(3), but also has been observed during cooler, darker periods of the year.
Two experiments were initiated September 17, 1981 when 5 to 7 eye
divisions of each cultivar were potted per 15 cm pot in a potting medium
composed of 3 sedge peat:l mason sand v/v. Both cultivars were placed
in a glass greenhouse where they received 1500-ft-c light maximum and a
temperature range of 650F minimum and 90oF maximum. Five days after
potting, plants were drenched with Vydate to preclude any possibility of
nematode contamination from divisions. Plants were fertilized at time
of potting and each 3 months thereafter with 14-14-14 Osmocote at a rate
of 4 g/pot. Treatments were factorial combinations of dolomite at 0, 5
and 10 1bs/yd3 and single superphosphate at 0, 5 and 10 lbs/yd3 and were
replicated 6 times.
Growth of both species was similar and the experiments were termin-
ated April 19, 1982 after 7 months. Plants were graded for size, color,
leaf size and leaf necrosis which was reflected in an overall plant grade.
Grade of Calathea insignis was best when plants did not receive either
dolomite or superphosphate (Table 1). Overall, best plants at every
dolomite level were produced without superphosphate and the poorest plants
were produced without dolomite at the highest superphosphate level.
Best Calathea makoyana were produced without dolomite and at 0 or 5
Ibs superphosphate/yd (Table 2). Poorest plants were grown with the
highest dolomite level without superphosphate and the highest superphos-
phate level without dolomite. These results are not nearly as clearcut
as with Calathea insignis and were partially due to increased chlorosis
associated with higher dolomite levels. Previous research (1) has shown
that elevated dolomite levels are responsible for Fe deficiency chlorosis
in Calathea makoyana, and this may have been partially offset by micro-
nutrient contaminants in superphosphate.
Professor and Center Director and Professor, Plant Physiology, Agricul-
tural Research and Education Center, 2807 Binion Road, Apopka, FL 32703,
Results of these experiments show that best growth of the two
calathea species tested were obtained without addition of dolomite (pH
without dolomite in these experiments ranged between 5.2 and 5.5). How-
ever, dolomite is necessary if superphosphate is utilized in the potting
medium, or if fluoride is present, since it can be responsible for
chlorosis and necrosis of Calathea. These data would indicate that
fluoride which is present in superphosphate at 1 to 2% reduced grade,
could be partially compensated for by addition of dolomite and that
Calathea makoyana is more tolerant of fluoride than Calathea insignis.
1. Conover, C. A. and R. T. Poole. 1982. Influence of nitrogen source
and growth tissue nutrient content of three foliage plants. Proc.
Fla. State Hort. Soc. 95:151-153.
2. Poole, R. T. and C. A. Conover. 1976. Fluoride and foliage. ARC-
Apopka Research Report RH-76-2.
3. Poole, R. T. and C. A. Conover. 1981. Influence of maximum air
temperatures and irrigation frequencies during high temperature
periods on growth of four foliage plants. HortScience 16:556-557.
Table 1. Interaction of dolomite and single superphosphate on
quality grade of Calathea insignis.
Dolomite Single superphosphate (Ibs/yd3)
(lbs/yd3) 0 5 10
0 4.3 3.1 1.8
5 4.1 3.5 2.1
10 3.7 3.3 3.4
z = poor quality, 3 = good quality, 5 = excellent quality.
Table 2. Interaction of dolomite and single superphosphate on
quality grades of Calathea makoyana.
Dolomite Single superphosphate (lbs/yd3)
(1bs/yd3) 0 5 10
0 4.2 4.3 3.0
5 3.6 3.4 3.8
10 2.3 3.4 3.6
z1 = poor quality, 3 = good quality, 5 = excellent quality.