School Science Lessons
Papaya Project
Updated: 2009-04-14
Please send comments to: J.Elfick@uq.edu.au
See: Interesting Websites
See:
Pests of Papaya, Queensland Department of Agriculture
(website)
Preface
Before teaching this project, discuss the content of the lessons with
a field officer of the Ministry of Agriculture and get advice on
planting
material, planting distances, site for planting, approved mulch,
composting,
and control of pests and diseases. Use only the procedures,
agricultural
chemicals and insecticides recommended by the local field officer of
the
Ministry of Agriculture. If you cannot control insects by hand-picking,
ask the Ministry of Agriculture to recommend a chemical spray. All
insect
sprays are dangerous. Show the students how to use them safely. Do not
get the spray onto your hands. Do not breathe in the spray. Wash your
hands
well after using spray. Keep the spray container in a safe place where
students cannot get it. Spray on a day of no wind but if you must spray
when there is a wind, spray down wind. Make sure the spray does not
blow
on other people.
Table of contents
Aim of the project
1.0 Introduction to a papaya project
2.0 Prepare to plant seed
3.0 Make a seed nursery
4.0 Care for young plants
5.0 Chose and prepare the land
6.0 Study the plant before transplanting
7.0 Prepare to transplant
8.0 Transplanting
9.0 Study the flowers
10.0 Study variation between plants
11.0 Care for the papaya garden
12.0 Culling and pollination
13.0 Pests and diseases
14.0 Harvest and profit
15.0 Papaya recipes
16.0
Understanding the records
17.0 Papaya varieties, "Paiola"
17.1 Papaya varieties, Babaco, mountain papaya
Aim of the project
The aim of this papaya project is to teach how to grow papayas
as a managed crop to provide a regular supply of fresh fruit or cooked
vegetable in their diet. These teaching notes tell you how to start a
papaya project and how
to look after the papaya plants to get plenty of fruit to
eat. Most people have seen papayas growing and they may ask why they
should
study them at school. There are three reasons:
1. The papaya is a useful addition to the diet because
a ripe fresh papaya contains lots of vitamin A and some vitamin C. If
picked
when hard and green it can be cooked like marrow and pumpkin. It can be
made into a tasty jam.
2. These teaching notes can be used to teach how to look after
a papaya crop in the
modern way, i.e. to increase the yield by controlling energy loss.
You can do this by paying careful attention to selection of seed, where
and how you plant seed, plant nutrition, pests and
diseases, looking after the papaya garden, and harvesting the crop.
3. Although most people have seen papayas growing, they may not
understand the plant that has a very interesting structure and life
history.
Study of this plant will broaden knowledge of their natural
environment.
1.0 Introduction to the
papaya
project
See diagram 58.1: Papaya with fruit
Planting Out
Decide whether to plant the papaya seeds into a seed bed
or into containers such as tins. Plants in a seed bed are easy to look
after but the plants may die after transplanting. Plants in tins can be
easily transplanted but they are harder to look after because they must
be watered regularly
for
10-12 weeks. Use both seed bed and tins to compare the results as in an
experiment.
You will need the following:
1. Large ripe papayas for seed
2. About 20 kg of lime or dolomite if your soil is very acid, ask
the agriculture field
staff. The soil pH should be 6.0-6.5.
If you wish to add fertilizer, you will need:
2.1 about 10 kg mixed fertilizer with a high content of phosphorus,
e.g. NPK 12-15-10
or NPK 9-25-25 or superphosphate.
2.2 About 10 kg of urea or ammonium sulfate.
3. Keep a crop diary and record the following:
3.1 When planting seed, germination, transplanting, culling, hand
fertilizing, picking
3.2 When and how much harvest, cost of seed, fertilizer, materials
for a nursery
3.3 Income from selling papayas
4. The papaya or pawpaw, Carica
papaya, is a member of an unusual
plant family, Caricaceae, that comes from South America. Papayas are
grown
in most tropical countries.
1. You need a ripe papaya fruit in the
classroom. Cut it in half
lengthways.
Also you need male and female papaya trees growing near by.
2. Keep one half, then cut up the other half and eat it. Note the
structure of the half papaya fruit. The fruit
can
be eaten fresh when ripe, or boiled when still green and eaten when
unripe
like a marrow. Some people eat the young leaves and flowers as a
vegetable
and eat the seeds for medicine. The white milky latex in the unripe
fruit
and leaves contains an enzyme call papain that can digest meat. It is
like
the action of pepsin in our stomach, so meat can be cooked in papaya
leaves
to make it more tender.
3. See the separate male and female papaya trees growing near by. See
the male or female flowers are on separate plants. Usually only the
female
plants produce fruit. Sometimes the male flowers become bisexual and
produce
some long thin fruit. There are some bisexual dwarf varieties, e.g.
variety
Solo from Hawaii.
4. The plant has shallow roots, a soft stem and big leaves. It should
be grown in well drained moist soil. It should be sheltered from strong
winds.
2.0 Prepare to plant seed
1. Select a papaya that has a good size and shape, growing in a group
of trees that all have good fruit. Leave this papaya on the tree until
the day before you want to use it,
2. The papaya garden planned in the Teaching Notes will have 20 mature
trees at 2 metres x 2 metres - a total area of 48 square metres. This
will
require 50 seeds planted at 15 cm and 50 seeds planted in 50 iron tins.
If you think that this is too big you cut the number of seeds planted
and
mature plants by half to provide 2 rows, each with 5 trees.
3. If you want to add fertilizer, you will need five matchboxes of
NPK 12-15-10 or 9-25-25 or 9-25-25 or phosphate sprinkled over the seed
bed, and a teaspoon of fertilizer in each tin.
4. Ask each student to bring to the lesson an opened clean tin with
four holes punched in the bottom and their name scratched on the
outside.
The tins can be jam tins or fish tins or drink containers
1. Show the papaya you have selected for
seed. The best
papaya seed comes from a large smooth fruit growing near by. Select a
papaya
from group of trees that all have good fruit.
2. Papaya seed must be used fresh or cleaned then sealed in an
airtight
jar. Put copper oxychloride in the jar to protect the seed from attack
by fungus.
3. You can plant seed 1. in a seed bed 15 cm apart and 1 cm deep
and 2. in tins. Both need shade. Papayas are often attacked by
nematode
worms in the soil, so planting seed in clean sand in tins may be the
best
method.
4. Line the tins with paper or leaves. Fill the tins with a mixture
of clean sand and dried crushed leaves or grass.
3.0 Make a seed nursery
See diagram 58.3: Papaya nursery
1. You will need: 1.1 Spades, forks, hoes, bush knife, rake, string,
tape measure. 1.2 Fresh papaya seeds. 1.3 Uprights, sticks and palm
leaves for a nursery.
2. If you want to use fertilizer, bring one fish tin of mixed
fertilizer
or superphosphate, a matchbox and a spoon.
3. The papaya seeds will take 3-4 weeks to germinate, and be ready
for transplanting in 10 - 12 weeks.
4. See the arrangement of seeds planted in the seed bed.
1. Select a small piece of land about 2 x 1
metres, with good topsoil
in a well drained position.
2. Dig up the soil to make a fine even seed bed. You can improve the
soil of the seed bed by adding sand and crushed dry leaves. Water well.
3. Fill the tins with a mixture of clean sand and crushed dried
leaves.
Water well. Scratch your name on the
tin.
4. Plant the seeds in the seed bed 1 cm deep in rows 15 cm apart and
cover with sand and dried leaves. Water again. Press down with a flat
board.
Plant one seed in each tin one cm deep. Water well.
5. Build four uprights, cross sticks and a light shade of palm leaves.
6. Water the seeds in the seed bed or tins every day. The plants will
germinate in 3-4 weeks. They will remain 10-12 weeks in the nursery
before
they are big enough for transplanting when more than 10 cm high.
7. If fertilizer is to be used, add five matchboxes of mixed
fertilizer
or superphosphate to the seed bed, or a teaspoon of fertilizer
to
each tin.
4.0 Care for young plants
1. Give this lesson near the nursery when the seeds have germinated.
2. Check that you can do the percentage germination calculation as
follows:
If you plant 50 seeds in the seed bed and 42 germinate to form
seedlings
then the percentage germination is as follows:
42 / 50 x 100 = 84% in
seed bed
If you plant 50 seeds in the tins and 47 germinate to form seedlings
then the percentage germination is
as follows:
47 / 50 x 100 = 94% in tins.
In this calculation the
conclusion is
that it is better to plant in tins to get good germination.
1. Examine the germinated seeds in the
nursery and
count them - number germinated in seed bed, number germinated in the
tins.
Let them dig up germinated seeds from the seed bed (not from the tins).
Keep the dug up seedlings wet.
2. Number of seeds germinated seed bed, tins percentage germinated:
Number germinated in seed bed x 100 = (call this "% seed bed")
Number planted in seed bed
Number germinated in tins x 100 = (call this " % tins")
Number planted in tins
Is there any difference between % seed bed and % tins?
5.0 Chose and prepare the land
See 6.9.14 Composting
1. You will need bush knives, hoes, forks, spades, string, tape
measure
or rule, sticks.
2. Go to a place where old papayas are growing;
a second place where the soil is badly drained or it is windy; and a
third
place that you have selected as suitable for the papaya garden.
3. Dig a hole in the place you have selected to show the soil profile.
1. At the first place, ask them whether it is
a
good place to grow papayas. At the second place, ask
the same question. At the third place, ask why it
is
a good place for a papaya garden. Examine the soil profile. The
soil
must be well drained.
2. Mark out the land 6 metres x 8 metres, and mark the four corners
with sticks. Then clear the land and hoe and fork it lightly. Mark each
2 metres x 2 metres position with a stick then dig a hole next to the
stick.
3. Put wood ashes or 1 tin of mixed fertilizer or superphosphate in
each hole.
6.0 Study the plant before transplanting
See diagram 58.6: Transplanting
1. Dig up some smaller plants, wash the roots and bring them to the
class.
2. Diagram F represents the general arrangement of parts of a plant
before transplanting. Be able to draw accurately
from
a living specimen using the diagram as a guide to understanding the
structure.
the shoot is the stem, buds and leaves
the axil is the angle between the stem and the leaf
the terminal bud may increase the length of the stem or form flowers
the axillary bud may remain quiet or it may form a lateral shoot (a
branch or
it may form flowers
the thickened parts of the stem called nodes produce leaves and
axillary
buds
the smooth parts of the stem between the nodes are called the
internodes
1. Draw Diagram IF on the chalkboard. Revise
the parts of a plant.
2. Draw the plants and label the drawing using your diagram.
3. Note length of plant in cm and number of nodes and internodes.
7.0 Prepare to transplant
1. Plants are ready for transplanting when they are more than 10 cm
high.
2. Transplanting experiment: seed bed or tins. You should plant around
10 holes in the papaya garden from plants in the seed bed and plant
around
10 holes from plants in the container tins. Papayas may die after
transplanting
and this experiment will show which is the best method.
3. Transplant on a dull wet afternoon.
1. Sequence for transplanting:
1. Dig four transplanting holes around
each fertilizer hole and fill them with water.
2. Water plants in
nursery.
3. Select plants from nursery.
4. Do not damage roots when
transplanting.
5. Level of soil up the stem in a papaya garden should be no higher
than
in a nursery.
6. Remove one leaf from each transplant to reduce water
loss through leaves.
Why do you transplant four plants quite close around each fertilizer
hole? (Because you will be keeping only 1 plant of each four when you
select
the largest male or female plant.)
8.0 Transplanting
1. You will need: Trowels or spades, watering can. If you want to
fertilize you will need about 3 tins of ammonium sulfate or urea.
2. To develop interest in these plants, make a transplanting map:
S John T Leah S Ben T Gaduna
S Raka T Mica S Dulci T Kori
S Mary T Judy S Uwa T Noris
S Esau T Lima S Poni T Hilton
S Boio T Odi S Rodi T Ulissiwaro
3. Have some mulch ready.
1. Dig four transplanting holes around each
fertilizer hole in the
papaya garden and fill them with water.
2. Water plants in nursery
3. When planting around the S holes, select four
plants each from the seed bed, dig them up very carefully and
transplant
them no deeper than in the nursery.
4. When planting around the T holes, select four
tins with healthy plants. Take the tins to the garden. Open the bottom
of the tin. Plant no deeper than in the tin.
5. Water all 80 transplants in the garden.
6. Place mulch around each plant, but not touching the plants.
7. If you want to use fertilizer, put 3 matchboxes of ammonium sulfate
or urea in each fertilizer hole.
9.0 Study the flowers
See diagram 58.9: Papaya flower
1. Papaya plants are unusual because most of them produce either male
or female flowers. You cannot tell which sort of flower will be formed
until the immature flowers have formed.
2. Female plants produce the large female flowers only, near the trunk
close to the base of the hollow leaf stalk. In the female flower each
petal
is separate and there are no stamens.
3. Male plants produce only male flowers. Many small flowers are found
hanging down on long branches. Some plants, e.g. a variety from Hawaii
called Solo, are bisexual having male and female parts.
10.0 Study variation between plants
See diagram 58.10: Papaya stem and leaf
1. There are 3 reasons why plants are different from each other:
1.1 They may have different genes. These are messages carried in the
pollen and ovules (in the
ovary) which are combined when a seed is formed. The genes tell the
plant what
characters to have, e.g. tall or short, white flowers or red flowers,
large fruit or small fruit.
1.2 They may be growing in different environments that affect their
growth, e.g., different
climates, soils, methods of crop management.
1.3 They may be different ages or at different stages of maturity.
2. Plants that grow from seed that had unlike parents will be unlike.
These plants will have a mixture of the characters of the parents.
Plants
that grow from seed that had like parents will be like each other and
like
the parents. Plants that are like their parents and each other over
many
generations are called a pure line.
3. In agriculture you look for good characters such as size of fruit,
amount of fruit, resistance to disease, consumer preference, and then
try
to produce a pure line that will have all the good characters.
3.1 Old axillary buds above the leaf scars and axillary buds in the
terminal cluster.
3.2 A stem is not branching unless the terminal bud has been cut off.
3.3 Wood is spongy or hollow.
3.4 The lamina of the leaf has tooth shaped lobes
3.5 The petiole of leaf is long and hollow.
4. You can produce better papayas by controlling
pollination. This can be done by:
4.1 finding a group of healthy papaya trees producing good fruit,
4.2 deciding which male plants fertilized them,
4.3 cutting down all other male trees,
4.4 for the next generation cutting down all male and female trees
not grown from the seed of
good papayas.
5. Imported seeds in packets are pure lines but they may not be
suitable
for tropical countries.
Locally produced seed will probably not be pure lines but they will
have good characters for
tropical countries.
6. Study of variation means looking at the different characters of
plants and deciding which are good and which are bad characters.
7. If you can find plants with good characters and use them only as
parents you can start producing pure lines for tropical countries. Do
not let plants with good characters be fertilized by pollen from plants
with bad characters.
8. Studying variation in plants is important to allow us to describe
accurately the different characters of plants and to decide which are
good
and which are bad characters.
9. Select some papaya plants outside the project
for study in this lesson.
9.1. Draw and label a stem.
9.2. Draw and label a leaf.
9.3. Draw the root of a small plant. Label: primary root, lateral
roots,
note depth of roots, note depth of roots in the soil, note any damage
by
pests or disease.
9.4. Draw and describe some characters of the plants selected for study
in
the classroom. They should be different from the plants in your
project.
The characters could be:
10.1 Fruit, diameter of middle fruit in bunch, diameter of largest
fruit, number of fruit on tree,
taste, colour, diseases
10.2 Habit, size of tree after 3 years, any branching
10.3 Stem, colour, diameter, any diseases
10.4 Leaves, shape, number in spiral, number in terminal cluster,
diseases
10.5 Flowers, shape, colour, size and number of parts of
male / female / bisexual flowers.
10.6 Root, depth, diseases.
10.7 Consumer preference, which fruits do people like and why.
11. Are there are other kinds of papayas growing near by or in the
villages?
What are the characters of these papayas and why do
people like them?
11.0 Care for the papaya garden
1. Make regular visits to the papaya
garden to see how the plants they transplanted are growing. Record
anything unusual.
2. Give an extra lesson on the need for careful
observations. Give a prize for the first report of flowers forming.
1. Always keep the garden free of weeds and
rubbish.
2. When the first flowers appear cut down excess male plants and
female
plants leaving 2 male and 18 females, each 2 metres apart. Two males
should
be on a windy side of the garden. Extra female plants can be cut back
to
height of 60 cm and left for a reserve if bigger ones die.
3. You can pollinate female flowers if you open the buds of male
flowers
and brush pollen on to the stigmas. This is called hand pollination.
When
stigmas go brown and die, pollination is successful and fruit will
form.
4. First harvest when the plants 9-12 months old. Then can harvest
for 4-6 years. If tree grows too tall, cut the top off in the dry
season
and it will form branches. You will need to prop up the branches.
5. Harvest by cutting stalk with a sharp knife. Do not bruise fruit
or get white latex on the skin.
12.0 Culling and pollination
1. Culling refers to cutting down the unwanted male and female plants.
Unwanted plants should not be pulled out unless diseased. They should
either
be cut across at ground level if no longer wanted or cut across 60 cm
above
the ground to be kept as replacement plants.
2. First select two male plants on the windy side of the papaya garden
so that the pollen can blow over all the female plants. Later you can
pollinate
by hand to make sure that all the female flowers will produce fruit.
3. Then cut across at ground level all the remaining male plants.
Leave only the tallest female next to each fertilizer hole. Cut the
other
females down to 60 cm.
4. Cut down all the other male plants in the school grounds.
5. You will need axes or bush knives.
1. Check the wind direction. Cut down all
male trees except two so
that wind can blow pollen from the two towards the female plants.
2. Cut down excess female trees to height of 60 cm.
3. Pick some male flowers still in the bud - peel back the petals
and brush the pollen on to the female flowers.
4. Draw a plan of the 20 plants left in the papaya
garden in their notebooks and show where the male and female plants
are.
13.0 Pests and diseases
See: Fungi, bacteria,
viruses
1. Pests and diseases may include:
1.1. Virus infection of leaves
1.2. Mildew fungus on fruit and leaves
1.3. Fungus rotting roots
1.4. Nematodes attacking roots
1.5. Fungus rotting fruit
1.6. Little red spiders
1.7 Fruit spotting bug
2. Plants that are well looked after and healthy can withstand most of
these pests and diseases. Do not allow any diseased tree to remain in
the
school grounds.
3. Viruses are so small that nobody knows whether they are living
or non-living things. When a virus causes a disease there is usually no
cure for it except for the plant to be very healthy and be stronger
than
the virus.
There are two forms of virus disease:
3.1 Dieback. When starting from the top the leaves become shrivelled
and fall off.
3.2 Yellow crinkle caused by Mycoplasma spp. At first, clear
spots appear on the leaves. Then the
younger leaves at the top
become yellow and curled. This disease is probably carried from
infected
tomato plants by
sucking insects.
The only cure for these virus diseases is to cut the tree down at soil
level, burn it, and let one of reserve trees grow up. Also pull up and
burn any tomatoes affected with yellow crinkled young leaves.
4. Fungi are the fur-like growths found in most rotting things. They
can digest plants like animals can and they can reproduce themselves by
letting lots of powdery spores blow into the air. A fungus can usually
be killed by a special chemical called fungicide.
There are three forms of fungus disease.
4.1 Root rot fungus can attack the roots in wet soils. The leaves from
the older leaves will
collapse down and wilt and the plant dies. This fungus can enter the
roots easily when
nematode worms attack the roots. Nematode worms are the small white
S-shaped worms
pointed at both ends. There is no treatment for this disease except
to drain the
soil. If the plant dies, pull it out with the roots and burn it but
do not replant.
4.2 Powdery mildew fungus attacks the leaves when cold winds are
blowing.
The name of this
fungus is Sphaerotheca. It
first appears as little dots under the
leaves
which turn into yellow
patches and then the leaf looks burnt and dried out. This can be
treated
with sulfur dust.
4.3 Fruit rots are difficult to control because the fruit is usually
infected when green and the rot develops when the fruit ripens. Watch
the
fruit closely for signs of fruit rot and pick the fruit
immediately any sign of rot appears. Rotten fruit should be burned.
Some types of papayas
are more easily attacked by fruit rot than others so when visiting
village gardens look out for
papayas not affected by disease.
4.4 There are various insects and mites, tiny spiders, which may attack
a papaya. If little red spider mites are found under the leaves, you
can
treat with sulfur spray. The fruit spotting bug attacks the leaf
stalks
and young fruit causing the fruit to drop. This can be treated with
insecticide.
1. Visit the papaya garden and look for any
signs of disease.
Take notebooks to the garden and write reports
there.
2. When some pests or diseases are found, draw
and describe the disease.
14.0 Harvest and Profit
1. In modern agriculture you are very interested in measuring the
yield
of our crop so that you can know how to increase the yield and make
more
profit.
2. Harvest the crop in a regular way, e.g. every Tuesday afternoon.
Do the harvesting properly by cutting the
fruit
stalks with a short knife and throwing away and burning any bad fruit.
3. The harvested fruit should be counted, measured and weighed. Sell
some papaya so that you can estimate the returns for the whole crop.
1. Show how to harvest papayas correctly
and what to do with bad fruit.
2. Record:
2.1. Number of papayas harvested.
2.2. Weight of papayas harvested.
2.3. Estimated returns (money that could be received from selling
harvest).
(If you do not actually sell the papaya you can still calculate or
estimate
the returns as if all were sold.)
3. Returns - production costs - establishment costs = Profit.
Calculate the value of estimated returns
What is the value of establishment costs, e.g. tools?
What is the value of production costs, e.g. seed, fertilizer,
insecticide,
razor blades?
What is the estimated profit?
4. In some countries the average commercial papaya plant produces
15-20 fruits
each year weighing 75 kg. What do your papaya plants produce?
15.0 Papaya recipes
1. Papaya is usually eaten when ripe as fresh fruit. Sometimes people
wrap meat in papaya leaves and cook by steaming over hot stones
underground.
The papaya can also be cooked as a vegetable and you should try out
some
of these recipes to show new ways of using this fruit.
2. The white juice in the skin of unripe papayas contains the enzyme
papain that irritates the skin of some people. Be careful to wash your
hands after touching the white juice.
3. Boiled papaya. Cut a green papaya into pieces and cook with salt
in the same way as cooking pumpkin or marrow.
4. Baked papaya with filling
1 large green papaya, cut in halves and seeds taken out to leave 2
shells
2 tablespoons of cooking oil
½ cup finely chopped onions
½ kg minced beef or I tin of fish
four tomatoes, peeled and chopped
1 teaspoon of finely chopped fresh hot chillies
1 teaspoon salt
pepper
Heat oven to temperature for baking
Heat cooking oil in large frying pan, drop in onions and cook for 5
minutes until soft but not
brown. Stir in beef or fish and cook lightly until pink colour gone.
Stir in tomatoes, chillies, salt, pepper and cook quickly until mixture
is about solid.
Spoon mixture into papaya shells. Place shells in an oven in roasting
tin. Put some boiling water into roasting tin. Bake for 1-1½
hours
until the papaya is soft.
5. Papaya jam
2 small ripe papayas
1 kg sugar
Cut papaya into 2 cm cubes. Place in a heavy saucepan and add 3
tablespoons
of water or lime
juice. Heat to boiling quickly then reduce heat to simmer for 30
minutes
until most of the liquid is gone. Stir frequently with a large spoon.
When
it is like a jelly pour into jars and seal.
6. Papaya chutney
1 green papaya
½ litre malt vinegar
1/4 kg sugar
½ cup raisins
1 teaspoon chopped ginger root
1 teaspoon chopped fresh chillies
5 teaspoons salt
Peel the papaya, discard seeds, cut into 2 cm cubes. Place papaya and
vinegar into a heavy saucepan. Bring to boil and cook briskly for 10
minutes,
stir occasionally. Now stir in sugar, raisins, ginger, chillies and
salt.
Simmer for 45 minutes until the papaya is tender. When thick enough
pour
into jars and seal.
7. Papaya and pepper sauce
½ cup of fresh chopped chillies
5 tablespoons chopped onions
2 tablespoons peeled finely chopped unripe papaya
1 teaspoon mustard
½ teaspoon salt
3 tablespoons vinegar
Put chillies, onion, papaya, mustard, salt and vinegar into small
saucepan.
Boil quickly and stir constantly. Cool before using.
(h) Pickled papaya
1 small green papaya, pealed and cut into 2 cm cubes
½ cup of chopped chillies
1 piece of ginger 21
1 tablespoon of salt
4 cups vinegar
Place all ingredients into cold vinegar and leave in a jar with a tight
cap for some days before eating.
8. Papaya and fish soup
(Some people say that this soup is very good for mothers breast feeding
their children)
1 whole fish
1 green papaya, peeled and cut into 2 cm cubes
1 small piece of ginger
Place in large saucepan, bring to boil and simmer for up to ½
hour.
17.0 Papaya
varieties, "Paiola"
Paiola is a papaya hybrid developed and promoted by the Malaysian
Agrifood Corporation (MAFC). "Paiola" is the commercial name for the
hybrid from the word papaya and the expression of "oo la la"
meaning "nutritional" in Polynesian. Paiola variety is small, like the
size of a palm, with golden yellow skin and sweet and deep crimson
flesh. It can also be kept a week longer than ordinary papayas.
17.1 Babaco,
mountain papaya
Babaco, Carica pentagona,
a naturally occurring hybrid of C.
stipulata and C. pubescens
from Ecuador is grown commercially in New Zealand, Israel and
southern California. It grows in a cool frost-free subtropical climate.
The five-sided, rounded at the stem end and pointed at the apex fruit
sets parthenocarpically so it has no seeds. However, The fruit is
juicy,
slightly acidic, low in sugar and with its own special flavour
Even
the skin is edible. It keeps well and the plants are very productive
and easy to grow. It is so compact that it can be grown in a
greenhouse. The mountain papaya Carica
pubescens has many seeds and is regarded as an inferior fruit
so is better cooked than fresh. It is more cold tolerant than Carica
papaya.
History
These teaching materials were written by Dr J. Elfick in the Solomon
Islands for the Australian Development Assistance Bureau.