Fruit Facts from
the
California Rare Fruit Growers, Inc.
Papaya
Carica papaya L.
Caricaceae
Common
Names: Papaya, Papaw or Paw Paw (Australia), Mamao (Brazil), Tree Melon.
Related Species: Babaco (Carica pentagona), Mountain Papaya (C. pubescens), Chamburo (C. stipulata).
Origin:
The papaya is believed to be native to southern Mexico and neighboring
Central America. It is now present in every tropical and subtropical
country.
Adaptation:
Papayas have exacting climate requirements for vigorous growth and
fruit production. They must have warmth throughout the year and will be
damaged by light frosts. Brief exposure to 32° F is damaging and
prolonged cold without overhead sprinkling will kill the plants. Cold,
wet soil is almost always lethal. Cool temperatures will also alter
fruit flavor. Papayas make excellent container and greenhouse specimens
where soil moisture and temperature can be moderated.
Description
Growth Habit:
The papaya is a short-lived, fast-growing, woody, large herb to 10 or
12 feet in height. It generally branches only when injured. All parts
contain latex. The hollow green or deep purple trunk is straight and
cylindrical with prominent leaf scars. Its diameter may be from 2 or 3
inches to over a foot at the base.
Foliage:
The leaves emerge directly from the upper part of the stem in a spiral
on nearly horizontal petioles 1 to 3-1/2 feet long. The blade, deeply
divided into 5 to 9 main segments, varies from 1 to 2 feet in width,
and has prominent yellowish ribs and veins. The life of a leaf is 4 to
6 months.
Flowers: The
five-petalled flowers are fleshy, waxy and slightly fragrant. Some
plants bear only short-stalked female flowers, or bisexual (perfect)
flowers also on short stalks, while others may bear only male flowers,
clustered on panicles 5 or 6 feet long. Some plants may have both male
and female flowers. Others at certain seasons produce short-stalked
male flowers, at other times perfect flowers. This change of sex may
occur temporarily during high temperatures in midsummer. Male or
bisexual plants may change completely to female plants after being
beheaded. Certain varieties have a propensity for producing certain
types of flowers. For example, the Solo variety has flowers of both
sexes 66% of the time, so two out of three plants will produce fruit,
even if planted singly. How pollination takes place in papayas is not
known with certainty. Wind is probably the main agent, as the pollen is
light and abundant, but thrips and moths may assist. Hand pollination
is sometimes necessary to get a proper fruit set.
Fruit:
There are two types of papayas, Hawaiian and Mexican. The Hawaiian
varieties are the papayas commonly found in supermarkets. These
pear-shaped fruit generally weigh about 1 pound and have yellow skin
when ripe. The flesh is bright orange or pinkish, depending on variety,
with small black seeds clustered in the center. Hawaiian papayas are
easier to harvest because the plants seldom grow taller than 8 feet.
Mexican papayas are much larger the the Hawaiian types and may weigh up
to 10 pounds and be more than 15 inches long. The flesh may be yellow,
orange or pink. The flavor is less intense than that the Hawaiian
papaya but still is delicious and extremely enjoyable. They are
slightly easier to grow than Hawaiian papayas. A properly ripened
papaya is juicy, sweetish and somewhat like a cantaloupe in flavor,
although musky in some types. The fruit (and leaves) contain papain
which helps digestion and is used to tenderize meat. The edible seeds
have a spicy flavor somewhat reminiscent of black pepper.
Culture
Location:
Papayas like to be warm with both sunshine and reflected heat, so the
hottest place against the house where nothing else seems happy is an
ideal location. They also like to be as free from wind as possible,
although this is not as critical as their need for sun. Papayas can be
grown successfully in shade, but the fruit is rarely sweet. They are
best planted in mounds or against the foundation of a building where
water can be controlled.
Soils:
Papayas need a light, well-drained soil. They are easily killed by
excess moisture. The soil needs to be moist in hot weather and dry in
cold weather. Since this is the opposite of California's rain pattern,
in addition to good drainage, plastic coverings to prevent over-wetting
in winter may also be worthwhile. Papayas do not tolerate salty water
or soil.
Irrigation:
Watering is the most critical aspect in raising papayas. The plants
should be kept on to the dry side to avoid root rot, but also need
enough water to support their large leaves. In winter the plant prefers
to remain as dry as possible. A plant that has been injured by frost is
particularly susceptible to root rot.
Fertilization:
The fast-growing papaya requires regular applications of nitrogen
fertilizers but the exact rates have not been established. Feed monthly
and adjust according to the plant's response. They can take fairly hot
organic fertilizing such as chicken manure if used with deep irrigation
after warm weather has started. Phosphorus deficiency casuses dark
green foliage with a reddish-purple discoloration of leaf veins and
stalks.
Pruning: Papayas
do not need to be pruned, but some growers pinch the seedlings or cut
back established plants to encourage multiple trunks.
Frost Protection:
Papayas need warmth and a frost-free environment, but can often
withstand light freezes with some kind of overhead protection. This can
be provided by building a frame around the plants and covering it with
bedding, plastic sheeting, etc. when frost threatens. Electric light
bulbs can also be used for added warmth. Potted specimens can be moved
to a frost-secure area. Prolonged cold, even if it does not freeze, may
adversely affect the plants and the fruit. Mexican papayas are more
hardy than Hawaiian varieties.
Propagation:
Papayas are normally propagated by seed. To start a plant, extract the
seeds from ripe papayas and wash them to remove the gelatinous
covering. They are then dried, dusted with a fungicide and planted as
soon as possible (the seeds loose their viability rapidly in storage).
Plant the seeds in warm (80° F), sterile potting mix. Seeds should be
planted in sterile soil as young papaya seedlings have a high mortality
rate from damping off. Potting soil can be sterilized by mixing 50-50
with vermiculite and placing in an oven at 200° F for one hour. Under
ideal conditions the seeds may germinate in about two weeks, but may
take three to five weeks. Gibberellic acid can be used to speed up
germination in some seasons. Seedlings usually begin flowering 9 - 12
months after they germinate.
Seedling papayas do not transplant
well. Plant them in large containers so the seedlings will have to be
transplanted only once, when they go into the ground. Transplant
carefully, making sure not to damage the root ball. To prevent damping
off, drench the potting mix with a fungicide containing benomyl or
captan. Set the plants a little high to allow for settling. A plastic
mulch will help keep the soil warm and dry in wet winter areas, but
remove it as soon as the weather becomes warm. Plant at least three or
four plants to insure yourself of having females or plant
hermaphroditic plants.
Papaya plants can also be grown from
cuttings, which should be hardened off for a few days and then propped
up with the tip touching moist, fertile soil until roots form.
Semihardwood cuttings planted during the summer root rapidly and should
fruit the following year.
Pests and diseases:
Thrips, mites and white flies as well as In red spider and fruit
spotting bugs are potential problems in some areas. The plants may also
be attacked by mildew, anthracnose, root rot and various virus diseases
Fruit flies often ruin the fruit in Florida and Hawaii. Nematodes can
attack the roots and are often a factor in the decline of individual
plant. Gopher damage can be avoided by planting in wire baskets. Papaya
plants should probably be replaced every 4 years or so.
Harvest:
Papayas are ready to harvest when most of the skin is yellow-green.
After several days of ripening at room temperature, they will be almost
fully yellow and slightly soft to the touch. Dark green fruit will not
ripen properly off the tree, even though it may turn yellow on the
outside. Mature fruit can be stored at 45° F for about 3 weeks. Papayas
are often sliced and eaten by themselves or served with a myriad of
other foods. They can also be cooked to make chutney or various
desserts. Green papayas should not be eaten raw because of the latex
they contain, although they are frequently boiled and eaten as a
vegetable. In the West Indies, young leaves are cooked and eaten like
spinach. In India, seeds are sometimes used as an adulterant in whole
black pepper.
Cultivars
Kamiya
A selection from Waimanalo. Solo type. Small to medium-sized fruit.
Distinct, blocky shape, very short neck. Deep yellow-orange skin and
flesh, firm, juicy, very sweet. Dwarf, high-yielding plant. Fairly
recent release from the University of Hawaii.
Mexican Red
A rose-fleshed papaya that is lighter in flavor than Mexican Yellow.
Medium to very large fruit. Generally not as sweet as Hawaiian types
Mexican Yellow
A very sweet and flavorful, yellow-fleshed papaya. Medium to large
fruit, can grow up to 10 pounds. Generally not as sweet as Hawaiian
types.
Solo
Fruit round and shallowly furrowed in female plants, pear-shaped in
bisexual plants. Weight 1.1 to 2.2 pounds. Skin smooth, flesh firm,
reddish-orange, very sweet, of excellent quality. Produces no male
plants, only bisexual and female in a 2 to 1 ratio. Introduced into
Hawaii from Barbados in 1911. Named Solo in 1919.
Sunrise (Sunrise Solo)
Pear-shaped fruit with a slight neck. Averages 22 to 26 ounces
depending on location. Skin smooth, flesh firm, reddish-orange, sweet,
sugar content high. Quality similar to Solo. Seed cavity not as deeply
indented as other Solo strains, making seed removal easier. Plant
precocious, maturing fruit about 9 months after transplanting, at a
height of about 3 feet.
Sunset (Sunset Solo)
Solo type. Small to medium-sized, pear-shaped fruit. Orange-red skin
and flesh. Very sweet. Dwarf, high yielding plant. Originated at the
University of Hawaii.
Vista Solo
Medium to large fruit depending on climate, 5 inches wide, up to 18
inches long. Skin yellow, flesh orange to yellow-orange. Hardy, compact
Solo type producing high quality fruit. Needs fairly hot weather to
develop sweetness. Self-fertile. Originated in Vista, Calif. by Ralph
Corwin.
Waimanalo (Waimanalo Solo, X-77)
Fruit round with a short neck, average weight 16 to 39 ounces. Skin
smooth, and glossy, cavity star-shaped. Flesh thick, firm,
orange-yellow in color, flavor and quality high, keeps well.
Recommended for fresh market and processing. Fruits of female plants
rough in appearance. Average height to the first flower is 32 inches.
Further
Reading
• Maxwell, Lewis S. and Betty M. Maxwell. Florida Fruit. Lewis S. Maxwell, Publisher. 1984. pp. 21.
• Morton, Julia F. Fruits of Warm Climates. Creative Resources Systems, Inc. 1987. pp. 336-346.
• Ortho Books. All About Citrus and Subtropical Fruits. Chevron Chemical Co. 1985. pp. 64-66.
•
Popenoe, Wilson. Manual of Tropical and Subtropical
Fruits. Hafner Press. 1974. Facsimile of the 1920 edition. pp. 225-240.
• Samson, J. A. Tropical Fruits. 2nd ed. Longman Scientific and Technical. 1986. pp. 256-269.
|
© Copyright 1996-2001, California Rare Fruit Growers, Inc.
|