Title: Papaya growing in Florida
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00084304/00001
 Material Information
Title: Papaya growing in Florida
Series Title: Papaya growing in Florida
Physical Description: Book
Creator: Lawrence, Fred P.
Publisher: Florida Agricultural Extension Service, Institute of Food and Agricultural Sciences, University of Florida
 Record Information
Bibliographic ID: UF00084304
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 228503840

Full Text
Circular 296


A^ in Florida

Florida Agricultural Extension Service
Institute of Food and Agricultural Sciences
University of Florida, Gainesville



Fred P. Lawrence

The information contained in this leaflet has been taken from
Circular 133A by Roy W. Harkness, Associate Chemist, Sub-Tropical
Experiment Station.

Papaya growing in Florida has been seriously
curtailed because of virus diseases. Apparently
several viruses may occur separately or in com-
bination in affected plants. Symptoms vary, but
usually the first is in irregular mottling of the
youngest leaves. Some areas become more trans-
parent or yellow than normal and the general
effect is to lighten the color of the leaves. Later,
mottling or distortion will spread to all new
leaves, irregular greasy-appearing streaks may
form on the leaf petioles and stem, and the fruit
will develop spots that usually become irregular
rings less than an inch in diameter. These
characteristic rings may be considered positive
identification. These rings do not always develop,
but at other times they may occur before mottling
of the leaves can be detected. Most plants are
badly damaged by these diseases and practically
stop growing. Infected plants will start produc-
ing fruit with objectionable flavor within two or
three months after symptoms are visible. How-
ever, some infected plants may seem to be only
mildly affected as long as good growing conditions
exist, but they may fail to recover from adverse
conditions such as flooding, low fertility, extreme
drought or cold weather.

The papaya is very sensitive to frost, although
it is not as limited in range as some tropical
plants. It will be severely damaged by exposure
to 310F. temperature but a large plant may not
be killed until exposed for a considerable time
to somewhat lower temperatures. Papayas have
been grown in backyards as far north as St.
Augustine but commercial plantings are all lo-

cated in more nearly frost-free areas. Even in
the vicinity of Miami there is sufficient frost
every few years to cause severe damage if frost
protection is not supplied.
The papaya thrives on almost any type of soil,
provided there is adequate drainage. Large
amounts of fertilizer are required on poor soil
but, when well fertilized, high sandy or limerock
soils will produce large crops of good quality
fruit. On a rich soil, such as the muck of the
Everglades, tremendous crops are produced but
the fruit is likely to be of poor quality.
Low, marshy ground, or land subject to periods
of overflow, should be avoided for growing pa-
payas. Water standing around the crown roots
for 48 hours is likely to prove fatal to the plant.
Papaya plants may be "male", "female" or bi-
sexual". Sex of the plant can be determined only
when flowers are produced. Male plants are easily
recognized by the long hanging panicles on which
the flowers are produced in clusters. These plants
ordinarily do not bear fruit. Female and bisexual
plants have flowers which are clustered at the
base of the leaf next to the stem. Female plants
have flowers that lack stamens so they must re-
ceive pollen from other plants in order to pro-
duce fruit. Bisexual plants have complete or
perfect blossoms with both a pistil and 10 stam-
ens but there is frequently a tendency for plants
of the bisexual type to revert to either the male
or female form. Bisexual plants that are, more
male than female may have flowers with pistils
only during the late winter and spring months,
so the plants will be barren a large part of the
year. Bisexual plants that are more female than
male will have blooms with less than 10 stamens.
When two or more stamens are missing the fruit
will be more or less misshapen and may have a
crease on one side. Rotten spots frequently form
in these creases before the fruit reaches maturity.
Yield from the bisexual plants in a good strain
of papayas will average nearly as high as from
the female plants. Most markets prefer the cylin-
drical shape and small seed cavity characteristic
of bisexual fruit rather than the nearly round
fruit produced by the female flower.
The only practical method of propagating pa-

paya is by seed. Seeds should be started in small
pots so the seedlings may be set in the field with-
out disturbing the roots. Cups made of felt paper
may be used but many growers use quart cans
with the bottom cut nearly out. When ready to
set in the field the soil is thoroughly moistened,
the bottom of the can is turned back, and the
soil is pushed out as a solid cylinder.
A mixture of sand and muck or any other good
high organic potting soil is satisfactory for grow-
ing seedlings. Small papaya seedlings are subject
to damping-off, so sterilization of the soil is a
wise precaution. If soil sterilization is impracti-
cal, damping-off may be minimized by providing
the seedlings with good aeration, avoiding excess
When using seed from fruit hand-pollinated
with bisexual pollen, two seeds to a pot are
enough. With other seed there will usually be a
considerable proportion of male plants so it is
desirable to plant about five seeds to a pot and
thin to three plants. These three plants are al-
lowed to grow until they blossom. The male and
other surplus plants should then be removed,
leaving one bisexual or female plant in a hill. If
no bisexual plants are present, about one male
plant per 20-25 female plants should be left for
The seedling pots should be watered frequently
enough to prevent the top inch of soil from be-
coming dry but not enough to saturate the soil.

Papayas should be planted 8 to 10 feet apart
both in the row and between rows, since the
leaves of vigorously growing plants will spread
more than 5 feet from the trunk. For convenience
in harvesting and spraying, a 15- to 20-foot drive-
way should be left every four or five rows. The
ground should be thoroughly loosened to a good
depth before planting. In the rocky soils of
Dade County the ground should be scarified quite
deeply and if the ground has stood for a year or
more after scarifying it should be dug up again.
In compact soil on low ground, careful arrange-
ments should be made for drainage between rows.
Plants should not be set any lower in the
ground than they were in the container. A hand-
ful of a mixed fertilizer such as 5-7-5 should be

placed in the hole around the plant and close to
it but not actually against the roots. After filling
the hole, a mulch of grass, peat moss, shavings
or other material should be placed around the
plants to help conserve moisture and prevent
growth of weeds around the small plants. In dry
weather the plants should be watered frequently
until they are well established.
In cooler parts of the state plants should be
set in the field in March or April to give them
the longest possible period without danger of
frost. In warmer sections, plants may be set out
at any time, but by planting in March or April
it is possible to get fruit by November or Decem-
ber. If planted after July 1, the plants go through
the winter season without fruiting and would
probably require 10 months or more to produce
fruit. If planted in late summer, however, they
probably would not be damaged much by a hurri-
cane in the fall and would produce fruit for a
time before the next hurricane season.
Papayas require quite large amounts of fer-
tilizer. The actual amount required depends on
soil conditions, rainfall, etc., but the following
schedule will serve as a rough guide. Beginning
a couple weeks after the plants are set in the field
a standard mixed fertilizer such as 5-7-5 with
more than 25% of the nitrogen from organic
sources and containing 3 units of available MgO
is used. This should be applied twice monthly,
starting with 1/4 pound per hill and increasing
gradually until at the end of six months the
rate is 1 pound. In addition to that, 5 to 10 pounds
of organic fertilizer such as chicken manure,
commercial sewage sludge or tobacco stems may
be put around the plants when small. In any
fertilizer program it should be remembered that
a heavy rain may wash out most of the soluble
nitrogen and potash. On the other hand, too high
concentration of fertilizer materials may be ob-
tained if repeated applications are made when
there is no rain or irrigation.
In general, best results are obtained by keeping
the plants growing vigorously at all times. Usu-
ally either nitrogen or water is the limiting factor
in growth. As the plants get older other elements
also must be present to maintain healthy plants

and good quality fruit. If the bottom leaves turn
yellow, a nitrogen deficiency is indicated. A grad-
ual yellowing of all the leaves may indicate lack
of water. It is desirable to keep the bottom leaves
green as long as possible because the growth of
the plant and the flavor and sugar content of the
fruit are directly dependent on the leaf surface.
In applying fertilizer, care should be taken to
spread it over the whole feeding area of the roots.
Papaya roots usually extend out farther than the
height of the plant.
Under Florida conditions it is frequently pos-
sible to double the papaya crop by irrigation.
Young plants are not extremely sensitive to dry
weather when first set in the field. But when
flowering starts, a week or so of dry weather
may cause them to drop their blossoms for a
considerable time. Older plants become somewhat
resistant to drought but will not produce full
crops in dry weather. On shallow soils such as
Dade County limestone, water may be needed
every five or six days. Extending the interval
to 10 days in warm dry weather might result in
as much damage from drought as no irrigation.
When properly cared for, and if free of virus
diseases, the papaya plant will continue bearing
good crops for at least two years after the first
fruit is obtained. Since virus diseases have be-
come prevalent, papayas sometimes produce no
marketable fruit and they seldom produce it for
more than a few months after infection. No
way is known to avoid the diseases, or to control
them, but if the plants are heavily watered and
fertilized, they are more likely to produce a crop
before they become infected. After they are
infected, plants do not respond favorably to
water and fertilizer, so all that can be done is to
salvage the fruit already formed.
For additional information on papayas, ask
your county agent for Circular 136A, "Papaya
Insect Control".
June 14, 1967-

(Acts of May 8 and June 30, 1914)
Agricultural Extension Service, University of Florida
United States Department of Agriculture, Cooperating
M. O. Watkins, Director

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs