School Science Lessons
Breadfruit Project
012-05-12 SPwp
Please send comments to: J.Elfick@uq.edu.au
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
1.0 Origin
2.0 Climate and soil
3.0 Tree and stem
4.0 Leaf
5.0 Roots
6.0 Male flower
7.0 Female flower
8.0 Pollination and germination
9.0 Fruit and seed
10.0 Cultivars
11.0 Seedlings
12.0 Suckers and cuttings
13.0 Planting
14.0 Harvesting
15.0 Fertilizers and shade
16.0 Pests and
diseases
17.0 Breadfruit as a food
18.0 Other uses
Introduction
To teach this project you should have access to seedlings growing during
the wet part of the year. Make a small shaded seed bed for growing the seedlings,
and the cuttings.
1.0 Origin
Breadfruit, Artocarpus
altilis (communis), Family Moraceae (mulberry family) comes from Papua New
Guinea, Indonesia, Malaysia and Western Micronesia. Migrating Polynesians
and Hawaiians brought it to Oahu Island, Hawaii. Seeded breadfruit may have
been taken from the Philippines to Mexico and Central America by Spanish
navigators. Later, in 1772 the French navigator Sonnerat in 1772 may have
brought seeded breadfruit from the Philippines to the French West Indies.
Following famine in Jamaica, in 1787, the British navigator Captain Bligh
collected potted breadfruit plants from Tahiti but the plants used too much
water leading to the famous "Mutiny on the Bounty" when the crew destroyed
the breadfruit plants. However, in 1791 he collected over 2000 different
kinds of the plants and later took them to Jamaica where the seedless varieties
later grew well. These varieties were later planted in the West Indies, Central
America and northern South America. Jamaica and St. Lucia are now the main
producers. In New Guinea, only the seeded type is grown for food and in Haiti
the seeded variety is more common. The pulp of this large green fruit is
used in the same way as potato and it stores well when dried or frozen.
The seeded (kluwe) are originally from Java, Indonesia, but also growing
abundantly in Suriname.
2.0 Climate and soil
Breadfruit is suited to the hot and humid tropical lowlands. Although it
is said that breadfruit need a temperature range of 16°-38°C, an
annual rainfall of 200-250 cm, and a relative humidity of 70 to 80%. it can
grow in dryer areas if irrigated. Similarly although it is said that the
breadfruit tree must have deep, fertile, well-drained soil, in the Pacific
islands the seedless breadfruit grows on sandy coral soils, and seeded types
grow on coral limestone islands. In Papua New Guinea, the breadfruit tree
grows wild along waterways and in freshwater swamps. Perhaps each variety
needs an environment with particular conditions. Some varieties are even
salt tolerant.
3.0 Tree and stem
1. The breadfruit tree, Artocarpus altilis (A. communis, A.
incisus) belongs to the mulberry family, Moraceae and is monoecious.
The normal, "wild type" has seeds and little pulp but it is still cultivated
in some regions, e.g. Papua New Guinea. The "cultivated" seedless type is
more widely grown, but sometimes seeds occur in seedless cultivars. The common
name is usually a translation of "bread" and "fruit", e.g. "fruta de pan"
in Spanish, "fruit a pain" in French. Some names distinguish the seedless
variety from the seeded variety, e.g. "suku" and "kulur" in Malaysia. In
the Philippines, the seedless variety is "rimas" and in Hawaii is "ulu".
In some classifications, the seedless variety is called var. apyrena
and the seeded variety, known as the breadnut, is called var. seminifera.
In the Southern hemisphere the breadfruit produces its fruit twice a year,
in the period March to June and again in the period August to November. A
good tree can produce more than one or two hundred fruit a year. Breadfruit
does not normally grow wild by itself and it must be planted by man
2. The breadfruit tree is fast growing and the largest may reach 26 m in
height, with a straight trunk to 6 m, 0.6-1.8 m in width and be buttressed
at the base. The spreading branches may have lateral foliage bearing branches
or long slender branches with leaves only at their tips. The young twigs
are green in colour but soon become brown and woody. There are two kinds
of marks on the small stems. The stipule scars are made when the stipules
fall off. They are just below each leaf. There are many small brown marks
on the stem, lenticels, that are breathing holes so that air can go inside
the stem. All parts of the tree, including the unripe fruit, have a milky,
sticky latex.
4.0 Leaf
See diagram 52.1: Leaf | See diagram
52.2: Stipule
1. Leaves are spirally arranged on the branch. The buds are 10-20 cm long
covered with big, conical, light green stipules. Later, the stipule drops
off leaving an obvious stipule scar on the branch.
2. The leaves may be evergreen on the wet tropics or deciduous in countries
with a monsoon. In high rainfall islands, the leaves stay on the tree. In
islands with a dry season, the leaves may drop off each year.
3. The leaves, are ovate, up to 20-90 cm long and 20-50 cm wide, and leathery.
They are entire at the base then deeply cut into 5 to 11 pointed lobes. The upper
surface is bright green and glossy on the upper surface with conspicuous yellow veins. The underside is dull
yellow to pale green, rough below with minute, stiff hairs. The leaf has
a short stout petiole 3-5 cm long and a strong midrib.
3. When a leaf is broken off a milky sap comes out, the latex.
5.0 Roots
1. Vegetative propagation is used so all the roots are adventitious roots
with a dense occurrence of feeding roots close to the surface of the soil.
2. Dig up some feeding roots. Also get some bigger roots about 2 cm thick,
because this is the size used to make root cuttings.
6.0 Male flower
See diagram 52.3: Male flowers | See diagram 52.4: Male inflorescence | See diagram 52.5: Male inflorescence
Flowers are tiny and similar to Jack fruit.
1. The breadfruit tree makes a multitude of tiny flowers, male and female.
The female flowers form first.
2. The thousands of small male flowers grow closely together on a drooping,
club-shaped spike. The flowers are 10-30 cm long, 2-4 cm thick, on stout
peduncles (flower stalks) and are soft like a sponge. They are first pale
yellow and then become brown. Each flower has a single small dark stamen
that makes the male pollen. After the male flower comes out of the stipule,
it takes early two weeks before the pollen is ready for fertilization when
the wind blows the pollen onto the female flowers.
3. Examine a male flower. In the Southern Hemisphere this can only be done
in early March or early August. Note the size of the small flowers and the
dark stamen coming from each flower.
4. Pollen forms two weeks after the flower opens, and the wind blows the
pollen to the female flowers.
7.0 Female flower
See diagram 52.6: Young fruit
1. The female flowers are massed in a rounded green head, about 6 cm long
and 4 cm wide, and stand stiffly on stout peduncles. The female flowers appear
about two weeks after the male flowers have first opened. The female flowers
are tightly packed together and embedded in the receptacles with tubular
calyx. From each flower comes the sticky part, the 2-lobed stigma which protrudes
above the calyx, on a narrow style. Three days after the female flowers open,
the stigmas can receive the pollen from the male flowers. At first the female
flowers are small and held straight up. As the flower grows and turns into
the fruit, the stalk bends down.
8.0 Pollination and germination
1. About 15 days after the inflorescence appears the male flowers shed pollen
to be carried by the wind to the female flowers. Hand pollination improves
the fruit set.
2. To observe how long it takes for one flower to grow to full size tie
a piece of coloured cloth around one flower to identify it.
9.0 Fruit and seed
See diagram 52.7: Mature fruit
1. The whole inflorescence, all the flowers, develops into a compound fruit,
a syncarp. The fruit is usually ovoid 9-45 cm in length and 5-30 cm in diameter.
Fruit can be oblong, cylindrical, ovoid, rounded or
pear-shaped. The thin fruit rind has a pattern of irregular, hexagonal
faces in "smooth" fruits or have a sharp, black point or green pliable spine
about 3 mm long on each face. Some fruits have a harsh rind like sandpaper.
The rind is usually green at first then yellow or yellow-brown when ripe.
When fully ripe, the fruit is somewhat soft, the interior is cream coloured
or yellow and pasty, also sweetly fragrant. When green, the fruit is hard
and the inside is white, starchy and fibrous. The fruit is seedless or nearly
seedless with a large central core surrounded by many aborted flowers which
form a moist pulp. When ripe, the fruit is softer, the inside is cream coloured
or yellow, pasty, and with a distinctive sweet smell.
2. The seeds are irregularly oval shape, rounded at one end, pointed at the
other, about 2 cm long, dull brown with darker brown stripes. The seedless breadfruit
is low in protein so the seeded breadfruit is more value as food. The seeds
soon lose their viability if they become dry.
3. In the centre of seedless fruits is a cylindrical core. Some fruits are
covered with hairs bearing brown, abortive seeds about 3 mm long. The fruit
is borne singly or in clusters of two or three at the branch tips. The fruit
stalk, pedicel, is from 2.5-12 cm long.
10.0 Cultivars
See diagram 52.9: Leaves of different varieties
1. Collect leaves of several varieties and take them into the classroom.
2. Describe each variety of breadfruit using the same descriptions as below.
3. The South Pacific Commission has published descriptions of about 160 varieties
from the South Pacific islands. One variety from each class of Samoan varieties,
classified by leaf shape, is described as follows:
Class I: Leaf entire (no toothing or division) or with 1 -3 lobes.
The "Tamaikora" fruit is gourd-shaped (constricted around the middle) 11.5
cm long, 7.5 cm, wide, and with many seeds. It can be eaten raw when ripe
but is highly perishable. The tree grows to 12-13.5 m in height.
Class II: Leaf dissected at the apex
The "Temaipo" fruit is round, 9 cm long and seedless. It can be eaten raw
when ripe.
Class III: Leaf moderately deeply dissected at apex
The "Uto Kuro" fruit is round, 12.5 cm long and does not deteriorate quickly.
Class IV: Leaf moderately deeply dissected on upper half
The "Tamaikora" fruit is oblong, 18-23 cm long, 12.5-16.5 cm wide, seeds
sparse, pulp eaten raw when ripe. The tree grows to 23-26 m in height and
bears 2 crops per year.
Class V: Leaf moderately deeply dissected, shape of leaf base variable
"Uto Wa" fruit is oval, 15-19 cm long, 12.5-14 cm wide.
Class VI: Leaf deeply dissected
"Uto Matala" fruit is round, 7.5-10 cm long and is especially fine when boiled.
The tree bears 3 times a year.
Class VII: Leaf deeply dissected, apex pointed
"Balekana Ni Samoa" fruit is round, 12.5-14 cm long, seeds sparse. It is
the best of all Samoan varieties.
Class VIII: Leaf deeply dissected, wide spaces between lobes
"Savisavi Ni Viti" fruit is oblong, 16-20 cm long, 10-15 cm wide, seedless,
and is especially good when boiled.
4. Some varieties from Tahiti are described as follows:
The "Havana" fruit is oval to round. The rind is yellow-green and spiny.
The pulp is golden yellow, moist, pasty, and separates into loose flakes
when cooked quickly over fire to become very sweet with excellent flavour.
The core is oval, large, and with a row of abortive seeds. The fruit is very
perishable, so it must be used within 2 days. Fruit borne in 2"s and 3"s.
It is said to be one of the best breadfruits.
The "Maohi" fruit is round and 15 cm wide. The rind is bright yellow-green
with patches of red-brown, rough, with spines, and often has much exuded
latex. The pulp is cream-coloured and smooth with very good flavour when
cooked slowly. The core is large. Fruit is borne in 2"s and 3"s. This tree
is a heavy bearer and is the most common breadfruit of Tahiti.
The "Paea" fruit is ellipsoidal, 28 cm long and 23 cm wide. The rind is yellow-green
and spiny. The core is thick with a row of brown, abortive seeds. The pulp
is bright yellow, moist, and separates into flakes when roasted for one hour
on an open fire. Formerly, "Paea" was reserved for chiefs only.
The "Pucro" fruit is spherical or elongated and large. The rind is yellow-green
with small brown spots, very rough, spiny, and thin. The pulp is light yellow
and smooth, of excellent flavour. It cooks quickly and is said to be one
of the best breadfruits.
"Rare Autia" The fruit is round, 15 cm across. The rind is dull green with
red-brown markings. The pulp is light yellow when cooked and separates into
chunks of excellent flavour. The core is large with small abortive seeds.
This cultivar is so superior it was restricted to royalty and high chiefs
only.
11.0 Seedlings
See diagram 52.8: Nursery
1. The seeded breadfruit is always grown from seeds, which must be planted
when fairly fresh as they lose viability in a few weeks. Pick a ripe fruit.
Leave it for three days until it is soft. Take out the seeds. Put the seeds
on the floor in a dry, shady place and leave them for one day until they
are dry. Then plant the seeds in the top of the seed bed and cover them lightly.
Water the seeds. Keep the seeds watered each day. They will soon sprout.
When the seedlings are two months old and between 15 and 20 cm high, they
can be dug up and transplanted. Build a small shelter for a seed bed and
put good soil in this place.
12.0 Suckers and cuttings
See diagram 52.10: Cuttings
1. The seedless breadfruit can be propagated by transplanting suckers from
the roots. Suckers can be induced by uncovering and injuring a root. Pruning
the parent tree will increase the number of suckers. Each sucker should be
root-pruned several times for months before taking it up for transplanting.
2. Root cuttings 3-6 cm thick and 20 cm long should have the ends dipped
in potassium permanganate solution to coagulate the latex, planted close
together horizontally in sand in the shade and watered daily, After about
6 weeks, calluses form and after about 2 to 5 months, roots form. Then transplant
the cuttings to pots, at a slant, and water daily for several months or until
the plants are 60 cm high. Allow a period of full sun before the final transplanting.
2. Dig up some pieces of root about 2 cm thick or a little less. The pieces
must be 20 cm long. Make sure to mark the top end. Make a sloping cut across
the bottom end, as you see in the diagram. Plant the cutting in a covered
seed bed in good soil and some compost. The cutting should be planted sloping,
not straight up. The cutting must be watered often. The cutting can be planted
out when it is about 15 cm. Plant the cutting with the top end out of the
soil.
3. Breadfruit scions can be grafted or budded onto seedlings of jack fruit
trees
13.0 Planting
See diagram: 52.11 Planting
1. Breadfruit is ultra-tropical and will not survive temperatures below 4oC. Growth stops and trees decline when temperatures drop below 16oC or above 35oC. Trees need lots of water, high humidity and deep, well-drained soil.
2. Plant young breadfruit trees in holes 40 cm deep and 0.9 m wide, 7.5-12
m apart in plantations, about 80 trees per hectare. Prepare the holes by
burning trash in them to sterilize the soil. Mix insecticide with the soil
to protect the roots and shoots from grubs. Trees grown from root suckers
should bear fruit in 5 years and be productive for about 50 years. Apply
seasonal standard mixtures of NPK. When the trees reach bearing age, in addition
apply 2 kg superphosphate per year to increase the size and quality of the
fruits.
3. The hole for the plant must be 60 cm by 60 cm and 150 cm deep. Some growers
put tin cans full of water in the bottom of the pit, then soil, then logs
and coconut husks until the hole is 3/4 full, then compost and good black
soil. Plant the young breadfruit in this good soil with the green shoot pointing
straight up. Most breadfruit plants do not tolerate salt spray from the sea.
14.0 Harvesting
Fruiting occurs continuously on and off all year long.
In the South Pacific, the tree usually fruits continuously with two or three
main fruiting periods. So fruit in all stages of development are present
during the year. In Hawaii, breadfruit are most abundant from July to February
and in the Bahamas June to November. However, in most places some fruits
may mature at other times during the year. Harvest breadfruits when maturity
is indicated by small drops of latex on the surface of the rind and the fruit
is still firm. If harvested by breaking the fruit stalk with a stick, some
bruising or splitting may occur. If harvested by catching by hand, the leaked
latex may cause some irritation. The yield varies from 25 to 200 fruits per
year, 15-30 tonnes per hectare depending on the variety, climate and fertilizing
procedures.
15.0 Fertilizers and shade
See 9.14.0: Composting
1 The young breadfruit will grow much better if it is given some plant food.
After planting in the it, some mixed fertilizer should be put on the soil
around the base of the young plant but not too close to it. The fertilizer
can be made by mixing together: 60 g of IBDU, 60 g of superphosphate, 30
g of potassium nitrate, 5 grams of coconut trace elements. This is the amount
to put around one tree. This fertilizer should be put on the plant every
three months. When the tree has grown bigger and has started to bear fruit,
the following fertilizer mixture can be put on the soil every six months.
200 g of IBDU, 200 g of superphosphate 100 g of potassium nitrate 15 g of
coconut trace elements. Mix some fertilizer and put it around the young plant.
Give older plants a larger amount of mixed fertilizer.
2. In a very hot climate young plants should be given some shade from the
hot sun, but some sun must shine on the plants. Make sure that if you shade
plants you give them fertilizer.
16.0 Pests and diseases
1. The main insect pests are soft scales, mealy bugs and ants. Fungus diseases
include soft rot of fruit caused by Rhizopus artocarpi that can be
controlled by Bordeaux mixture. Rosellinia kills young trees and Fusarium
causes die back, Pythium causes root rot. Phytophthora attacks
the fruit, Phomopsis, Dothiorella and Phylospora cause
stem end rot. Fruit flies can damage ripe fruits.
2. Some growers prune branches that have borne fruit and would normally die
back to stimulate new shoots and keep the tree from growing too tall for
convenient harvesting.
17.0 Breadfruit as a food
1. Most varieties of breadfruit are purgative if eaten raw so they must be
boiled twice and the water thrown away before using them for food. However,
some cultivars can be eaten without cooking. Some cultivars contain the sterol
cycloartenol. Fresh fruits are baked or boiled and served with garnishes.
Breadfruits are also used in making many other dishes, from soup, to chowder,
to custards and even bread. Unripe
fruits are roasted or pickled and used as vegetables
2. Breadfruit
can be used like a potato or winter squash; it can be baked, boiled, fried,
or roasted. Some cooks soak it in water overnight before peeling it. It can
be cooked without peeling. Baked or roasted breadfruit is good with butter,
salt and pepper. Breadfruit may be eaten ripe as a fruit or eaten under-ripe
as a vegetable when it is picked while still starchy and boiled or roasted,
sometimes stuffed with coconut before roasting. The pulp may be sliced and
fried in palm sugar syrup until brown. Ripe fruits can be baked whole or
steamed. Breadfruit soup can be made by boiling under-ripe slices. The pulp
of ripe breadfruits can be combined with coconut milk and baked to make
a breadfruit pudding. Breadfruit can be prepared as a sweet pickle. Overripe
breadfruit can be used to make chips like potato chips or fries.
3. In some Pacific islands the fruits are peeled, the pulp mashed with sea
water, sometimes baked or left raw, then left to ferment for some time in
pits lined with banana leaves. The food called poi is made from boiled firm
fruits, pounded to a paste with added water then strained through a cloth
before eating.
4. The fruit can be preserved by being cut into slices, cooked and dried
in the sun or dried over hot stones in a fire pit or dried in a copra dryer.
5. Dried fruit has been made into flour and combined with wheat flour or
boiled to make porridge. Breadfruit flour contains 4.% protein, 77% carbohydrates,
and 330 calories per 100 g. Cassava flour contains, 1% protein, 84% carbohydrates,
and 347 calories per 100 g. Two enzymes occur in breadfruit, papayotin and
artocarpine.
6. The fallen male flower spikes can be boiled as vegetables or candied
by cooking in syrup. The seeds can be boiled or roasted before being eaten
like chestnuts. Under-ripe fruits can be cooked for pig feed. The leaves
can be eaten by livestock. The fruits can be kept under sea water until needed
also ripe fruits fallen from the tree can be put into polyethylene bags and
kept in refrigeration temperatures down to 12°C. Partly roasted fruits
can be transported by sea. Canned breadfruit is exported to Europe.
7. Cook breadfruit when it begins to ripen. When fully ripened it is mushy to eat.
18.0 Other uses
The latex was formerly used as birdlime to catch birds and for caulking
canoes. The yellow grey wood with markings is light in weight, not hard but
strong, elastic and usually termite resistant. It is used for house construction,
furniture, partitions, surfboards and drums. The bark fibre can be used to
make clothing, tapa cloth. Roasted leaves are used in local medicines.
produces in 4 years
History
These teaching materials were originally written and illustrated by Mr J.
A. Sutherland, Faculty of Education, University of New England, Armidale,
Australia and later edited by Dr J. Elfick, School of Education, University
of Queensland, Brisbane, Australia.