School Science Lessons
Banana Project
Updated: 2008-07-16
Please send comments to: J.Elfick@uq.edu.au
See also: Interesting websites
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.
Contents
Contents
1. Introduction to the Banana Project 11. Planting
2. Leaf 12. Care for plants
3. Growth of leaves 13. De-suckering
4. False stem 14. Fertilizing
5. Corm 15. Pests
6. Roots 16. Diseases
7. Inflorescence (Flowers) 17. Fruit bunch
8. Choosing a site 18. Harvesting
9. Preparing ground 19. Costs, returns and profits
10. Planting material -
1. Introduction to the Banana Project
See Diagram 51.1: Village banana plant and cultivated banana | See diagram 51.1.1: Banana plants
Bananas can be grown on atolls but it needs special care to make them grow well. The aim of this project is to show how to increase the yield of bananas and grow bananas for profit. You will need examples of village and cultivated bananas or use the diagrams. There are hundreds of different kinds of bananas but in this it is important that you teach the difference between traditional (wild) bananas and cultivated bananas, Musa acuminata.
Bananas are probably the second most important staple food on atolls after sweet potato. Bananas with a high sugar content are usually eaten raw. Those with a high starch content, sometimes called plantains, are usually cooked. Bananas are also healthy food because they contain Vitamin A. A banana may contain more potassium, calcium, phosphorus, iron, Vitamin A, thiamin, riboflavin, Niacin, and ascorbic acid than an apple! Very ripe bananas are easily digested which helps sick people and they are an excellent weaning food for babies when they stop drinking their mother's milk. The male banana flower can be boiled and eaten as a vegetable. The stems and leaves can be used for plates, wrapping, umbrellas and cattle feed. The fibres can be used to make a cloth called batik.
What are the different kinds of bananas used at home? Are all bananas the same? What are the different types of village bananas? What are the different uses of village bananas?
There are two main kinds of bananas - traditional and cultivated. Traditional bananas grow wild and are easy to grow. Cultivated bananas were introduced from other countries. They are harder to grow but they produce more fruit. Cultivated bananas may be quite different from traditional or village bananas. They may be genetically different. They may have higher yield than village bananas if they are fertilized and cared for properly. Can you see some differences between traditional and introduced bananas?
Traditional bananas Cultivated bananas
Many hundreds of varieties Few varieties (cultivars), e.g. Cavendish, Gros Michel, Lady Finger
Can grow on poor soils Need good soils
Are easy to grow Can be difficult to grow
Get less pests and diseases Get more pests and diseases
Better taste Not so tasty
Some have no fruit All have big fruit
Some have red juice None have red juice
Some fruit contain seeds No fruit contain seeds
Leaves stiff and grow upright Leaves hang down
Smaller plant, not last long Larger plant, lasts long time
Smaller fruit bunch, some upright Larger fruit bunch, all hang down
Leafy bracts over fruit red underneath Leaf bracts over fruit yellow underneath
Few black marks on false stem Many black marks on false stem
Canal through the petiole closed Canal through petiole open
2. Leaf
See diagram 51.2: Leaf
You will need a banana leaf in the classroom, or take students outside to see a banana plant.
Draw a whole banana leaf and include the following four parts:
A large flat leaf blade, the lamina, that has many small veins that run close together
Thick strong middle of the leaf, the midrib
A strong leaf stalk, the petiole, that holds the leaf up to the sun
Thick elongated part of the leaf stalk, the leaf sheath. The end of the leaf sheath is the leaf base.
A leaf will stop it making food by photosynthesis if:
strong winds blow the leaf off the plant.
the leaf is eaten by insects or other animals
the leaf is killed by a disease
a creeper or vine grows over a leaf and stops the sun shining on it.
The leaf edges may tear or break in a strong wind. This does not hurt the leaf much. When a leaf is old, it may have many tears in it.
3. Growth of banana plant
See diagram 51.3: Growth of banana plant
You will need a banana plant in the classroom, or take the students to see a banana plant.
The banana plant needs 8 - 9 green leaves before it will make the flowers that turn into the fruit. New leaves are made as the older leaves die and hang down.
Note the number of leaves on a banana plant. Record the length and width of some big leaves.
The banana "tree" is really a collection of big leaves. The leaf stalks, petioles, of the leaves wrap around each other to form a false stem, pseudostem. The real stem and roots are underground. The youngest leaf grows up through the middle of the plant. At first it is rolled up, called a candela, but later it opens and hangs down. Later, a flowering stem, inflorescence, grows up from the underground item. The flowering stem grows out the top in the middle of the plant, turns down and produces flowers and fruit. After the flowering stem appears, no more leaves can grow. From the underground stem buds grow to form new shoots, suckers. Suckers grow to form the next "trees".
4. False stem
See diagram 51.3: Leaf bases
You will need an old banana stem that has died or a stem from which the bunch of fruit has been cut. Use an axe or a bush knife to cut off a piece of this stem about 30 cm long. Be careful! Spiders and other animals that can bite you may be living in the false stem!
The "stem" is really a collection of leaf bases wrapped around each other so it is called a " false stem ", pseudostem. It is the "trunk" of the "tree".
Draw the cut end of a stem. See the leaf bases wrapped around each other.
Take off the leaf sheaths or leaf bases one by one until you can see there is no stem inside. You may see a small hard piece of the flower stalk in the centre.
5. Corm
See diagram 51.5: Corm
You will need a corm of an old banana plant
The true stem of the banana plant is an underground stem, a rhizome. The thick part is the corm. The corm makes shoots that grow into branches or other corms. New plants come from these shoots.
The branches and suckers grow very close together to form a clump, a rootstock with many shoots. It is difficult to see the shape of the corm so cut off a piece of corm by putting a spade or a bush knife between a strong sucker and the side of the main plant. Wash it and cut off some roots.
Compare your cut piece of corm with the diagram. Suckers grow from the dormant buds called "eyes" on the corm. Note that each sucker formed is higher than the corm it came from so you should plant suckers deeply in the soil. If the land is sloping, the suckers are usually formed on the uphill side. If left alone, generations of banana plants will gradually move up a hill.
6. Roots
Just before the class, you will need to cut off a piece of corm with roots.
The roots of the banana plant are shallow, not deep in the soil. The plant can be easily blown over by a strong wind. Do not dig deeply close to the plant because you may cut the shallow roots. Cutting off weeds with a bush knife is better than trying to dig them out deeply and damaging the roots.
Roots near the surface of the soil may become dry if there is no rain. So use as mulch dead leaves and dead grass on top of soil to keep the surface soil moist.
Dig around the growing corm to find some shallow roots.
7. Flowering stem
See diagram 51.7.1: Inflorescence | See diagram 51.7.2: Flowers - male | See diagram 51.7.3: Flowers and fruit | See diagram 51.7.4: Banana berry
You will need a banana plant with fruit on it. If there is no fruit ready to see, teach this later when the fruit bunch is growing up.
The axis of the flowering stem, inflorescence, is called the stalk.
The flowers are covered by purple bracts, small leaves or leaf scales that lift then shed as the flower grows. The flowering stem before the bracts have lifted is called a bud.
Individual flowers appear and develop from bisexual flowers to male or female flowers by losing their male or female organs. The female flowers develop into the clusters of seedless fruits without need of pollination.
The male flower is at the end of the stalk, with a thin leaf-like covering, is called the "bell" or "flower" or "navel".
The female flowers further up the stalk become banana fruit.
When the fruit is very small, it is angular and does not have much stored food inside.
The usual stage for cutting for transporting some distance to market or for export is green fruit with the angles still just showing. When the angles have disappeared, the fruit is at the " round full bunch" stage and should be eaten soon.
8. Choosing a site for the banana project
You should discuss the site for a banana project with the school principal, local community and a filed officer of the Ministry of Agriculture. Prepare to first take the students to several unsuitable places then take them to see the place you have already chosen for planting the bananas.
The place you choose for the banana project should have the following properties:
Be near the school, on flat land or land sloping towards the North
Water table is not too deep because you will plant about 1 metre above the water table
Sunny all day, not shaded by big trees
Sheltered from strong winds, e.g. sheltered but not shaded by buildings or trees
Annual rainfall more than 1200 mm during 12 months
Deep soil with plenty of plant nutrients, not sandy soils or clay soil
Soil pH between 5 and 6
Land that has not grown bananas for two years to avoid by pests and diseases left behind by the old banana plants. Do not use land that has wild bananas growing on it or where there are dead banana plants.
Clear the bush two months before planting but leave some trees on the windy side as a windbreak, or plant Leucaena.
On the flat land the bush should be burnt but this may cause soil erosion from rain on sloping land so leave some plant cover there. Plant a cover crop to protect the soil and shade any grass and weeds, e.g. cowpea, pigeon pea, velvet bean, Crotalaria and Pueraria.
Plant at least 4 m apart, but planting distances depends on the fertility of the soil and on the size of the variety. Ask the Ministry of Agriculture for advice on planting distance. Plants should be grown closer on fertilized or richer soils and further apart on unfertilized or poorer soils.
Examples of planting distances:
Variety Distance apart on the square
Dwarf Cavendish 2 m
Giant Cavendish, Mons Mari, Williams 3 m
Lady Finger 4 m
In some places you are not allowed to plant bananas near houses or dormitories because some people say they attract mosquitoes.
On atolls, the side of an old pit for swamp taro (Cyrtosperma sp.) is a good place or you can dig a special planting hole in another place. You may find a suitable place sheltered by coconuts, or by a house, or by bushes on the lagoon side of an atoll. The exposed windy side of an atoll near the ocean is not a good place.
9. Preparing ground for planting
See diagram 51.9: Make planting holes
You will need digging tools, bush knives, compost, fine black soil, dead leaves, coconut husks. Get advice from the Ministry of Agriculture about using chemical herbicides for preparing ground, e.g. glyphosate weedicides.
Clear the land around the planting places, cutting down weeds and bushes. The ground should become "clean weeded" no weeds at all.
Dig the holes about 3 m apart and 60 cm or 2 spade blades deep and wide.
Fill the bottom of the planting hole with coconut husks and dead leaves and some fine sand. They must push the sand down into the spaces between the husks so the soil is quite firm.
Fill with rotten compost and legume cover crops such as cowpea or Crotalaria. If you leave the holes open, make sure that people do not fall into them.
On top of this put a small heap of compost mixed with fine black soil. The planting material will be planted into this soil and compost mixture. Add some pig manure or sprinkle a matchbox full of mixed fertilizer.
10. Planting material
See diagram 51.10: Planting naterial
You will need a large plant to show how to cut off the different kinds of planting material. Try to obtain planting material from agricultural officers. The planting material must be clean. It should not have any holes or spots on it due to insects or disease.
The different kinds of planting material, sets:
1. Pieces of corm called a "bit". Each bit must have a bud called "an eye". Bits must be planted in the soil the same way up as it was when cut off. Bits grow slowly.
2. Suckers are offshoots from the parent corm. Suckers with thin narrow leaves like swords, "sword suckers", can be used for planting. Suckers with broad leaves, "water shoots", are useless for planting and should be removed and burnt.
Small suckers, "peepers", can be used for planting material but they must include a piece of corm at the bottom.
3. The best planting material are large suckers up to 1 metre high and at least 15 cm across.
Use as many large suckers as you can get. To transplant larger suckers, cut off all but six of the large green leaves.
Trimming the suckers
Use a large with a sharp knife to remove the roots so that you can see the white corm. Use a small knife to cut out any red brown spots or tunnels caused by pests. Work quickly because the cut corm will darken in the air so you cannot see the spots.
Get a whole banana plant and identify the different kinds of suckers. Cut suckers away from the mother plant by pushing a spade or knife down between the sucker and the main stem. Draw the different kinds of planting material.
Store the planting material in a shady, dry place, e.g. under a house. Leave the suckers there for four days until the cut surface of the corms have healed over. If the sucker is planted soon after it is cut off, the corm may rot and die.
11. Planting
See diagram 51.9: Planting
Plant one sucker first as demonstration then students plant the other suckers. Bananas are usually planted at the beginning of the wet season but can be planted all year round. The bunch of fruit will be ready for harvest in about 12 months. The first crop after planting is called the plant crop. Later crops from the suckers are called ratoon crops.
Make a hole in the heap of good soil and compost in the middle of the planting.
Hold the top of the sucker when you have put it in the hole. The bottom of the sucker should be 12 cm below the soil surface. Fill in the soil around the sucker. Put more soil around the stem.
Put dead leaves on top of the soil all around the sucker. Make sure there is a hole at the top of the planting place so that rain and water will run down to the sucker.
Tread on the soil around the sucker to make the soil firm.
Water the soil around the sucker.
12. Care for plants
See diagram 51.3: Generations 1 to 3
Encourage students to visit the banana project each day and note any problems. Get advice from the Ministry of Agriculture about using chemical herbicides for weeding, e.g. glyphosate weedicides.
Take the students to see some growing bananas. Show them different ways to care for bananas and ask them why they should be done. In some places it is not the custom of the people to do all these things. The people may feel that the plants can look after themselves. However, commercial banana growers say that in the first three to four months, bananas need lots of care, soil moisture and fertilizer for the best growth and fruit production. This will increase the weight of the first bunch and how many "hands" the banana will have.
Weeds compete for water, nutrients and light. Weeds may allow pests and diseases to be near the bananas and attack them. For the first year of growth chip away weeds and grass between the plants with a hoe. The ground in the banana project should be weed free but if the manual weeding is done carelessly the roots of the bananas will be damaged.
Plant a cover crop to control weeds.
You can also use clean mulch to control weeds, but make sure that there are no insect pests in it.
Watering and Mulching
Keep a mulch around the plants to prevent water loss by evaporation. Give the plants water especially when they are young and when there is no rain. Mulching retains moisture, cuts down on weed growth, and helps the plant absorb the fertilizer better. Make mulch by chopping the older banana leaves, banana stalks and plants harvested and cut down. The composted banana leaves and plants will add potassium to the soil.
Thrashing is the cutting down of all dead leaves because they may have pests and diseases living in them. Cut them down with a bush knife and burn them. Cut with an upward stroke of the bush knife.
Propping is to place a prop under the stalk of a hand of fruit because sometimes the bunch is too heavy for the plant. Place the prop after the last hand of fruit has formed.
De-belling means to cut off the male flower or bell 100 cm from the last hand because it makes the bunch much too heavy and may attract birds. Bunch covers
Bunch covers are made of blue plastic. They let the fruit ripen evenly and protect the fruit from insects, flying foxes and birds. Cut a hole in the bottom to let the water out.
13. De-suckering
See diagram 51.13.1: Stool | See diagram 51.13.2: Sucker
The best way to teach the importance of this procedure is to take students to see stands of bananas that have been de-suckered and stands that have not been de-suckered. Alternatively you could set up a trial where you divide your banana project into two and de-sucker only half the bananas to show the difference in yield.
If the banana plant is just left alone, it will soon be surrounded by many suckers. These suckers will compete with the mother plant for water and plant food and so the fruit formed by the mother plant will be very small. All the useless suckers should be cut out before they get too big. If you do this, you will have a "stool" or group of bananas that never has more than four plants in it:
one large plant one bearing fruit
one smaller plant but the next to bear fruit
one medium-sized sucker, and
one small sucker.
To make sure that have only one or two strong suckers for the next generation, allow only one new sucker to grow every three months. Two strong sword suckers should be selected to bear fruit for the next crop. One of these can be allowed to grow for the new crop called the follower crop. The other can be cut out for planting in another project. The other suckers should be cut out after they are more than 30 cm tall.
Use a sharp knife to cut the unwanted suckers off at ground level, scrape out the remains of the sucker and pour in a teaspoon of kerosene. It must be done when the suckers are very small. Cutting the tops of the suckers is useless because they will just grow again. The whole sucker and its bit of corm must be cut away from the mother plant. De-suckering must be done each month.
Some village people refuse to de-sucker their bananas because they may not bother about it or they believe that they should not like to kill things if there is no need to do so. How would you explain to villagers about the need for de-suckering? You could say that having lots of suckers is like having too many chickens feeding from one small tin.
14. Fertilizing
See also 6.9.15.0: Fertilizing the soil | See also 6.9.14 Composting
You will need fertilizers or coconut husks for mulch. Ask the Ministry of Agriculture for advice on fertilizing bananas because suitable application of fertilizers depends on climate, variety and soil type.
Bananas need heavy applications of fertilizer near the surface of the soil because of its shallow roots. Quick growth during the first 3 months to get the largest possible leaf area is necessary for high yield. However, top dressing with fertilizer after 6 months is not desirable. Each plant needs about 2 kg of mixed fertilizer each year, but this must be put on a little at a time, not all at once. In some places, farmers feed the bananas NPK 6-2-12 each week and feed magnesium every two months. The fertilizer must not be put too close to the plant. It should be spread out evenly in a circle 1 metre wide around the stem of the plant.
Sprinkle 0.25 kg of mixed fertilizer on the ground around each banana plant. There is no need to dig it in, just sprinkle it over the leaf mulch. If you do not have any fertilizer, put many coconut husks on the soil around each plant. Put the husks with the cup upwards. Husks contain some potash plant food and the rain will wash this wash this into the soil. Put some pig manure around the plants if there is no fertilizer, but the fertilizer is best to use
Pull out any weeds that are growing near the plants.
What are the advantages of using fertilizers? Why is it not the custom of the people to use them? Can you do a field trial to compare the yield of banana plants with fertilizer with the yield of plants without any fertilizer?
15. Pests
See diagram 51.15: Insect pests
Ask the agriculture field officer about pests and diseases of bananas in your area and show the agricultural officer any infected plants from your banana project.
Look for signs of pests and diseases in the school banana project and in other banana projects.
Banana Root Nematode, burrowing nematode, worm or eel worm, Radopholus similis.
This nematode worm lives in most banana growing regions. The tiny worms make red brown tunnels in the banana roots and corm. A fungus, Fusarium oxysporum, infects the tunnels causing root rot or blackhead disease. The roots rot and weaken the plant that may topple over in strong wind after the heavy fruit bunches have formed.
For control of Banana Root Nematode:
Select clean land and keep land clean of weeds, dead leaves and trash.
Select clean suckers for planting material.
Plant in land that has a well grown cover crop, e.g. cowpea, pigeon pea, velvet bean, lablab, Crotalaria, Pueraria, Calopogonium. Do not plant bananas near crops that may have nematodes in their roots, e.g. corn (maize), sugar cane, Siratro, green panic grass.
After trimming the suckers put the planting material in hot water at 55oC for 20 minutes, dry in the sun, then plant straight away. It is not easy to judge how long to keep the planting material in the hot water to kill any nematodes but not cook the corm.
Treat planting material with a chemical that kills nematodes, nematicide, e.g. DBCP.
Treat infected soil with a nematicide.
Banana weevil borer, banana root borer, "banana beetle", Cosmopolites sordidus
Banana weevil borer is the most serious pest of bananas in the South Pacific. The weevils are about 3 cm long, with a long snout, and are brown black in colour. They cannot fly. They live rotting false stems lying on the ground. At night they burrow into the corm above ground and lay white eggs which hatch out larvae. The white larva bores many round tunnels in the corm that let in fungi that can cause the whole corm to rot and the plant dies.
s of control of Banana weevil borer
Select clean land and keep land clean of weeds, dead leaves and trash.
Select clean suckers for planting material.
Make a weevil trap.
Cut a piece of corm and place it, cut side down, on a small stone. Weevils will live under the piece of corm. These weevils can then be collected every few days and killed. Banana scab moth, Nacoleia octasema
The larvae feed on young female flowers leaving a scab and may attack the fruit in the bunch. Control by clearing away any dead plant material around the plant base.
16. Diseases
See diagram 51.16: Diseases
Ask the agriculture field officer about pests and diseases of bananas in your area and show the agricultural officer any infected plants from your banana project.
Look for signs of pests and diseases in the school banana project and in other banana projects.
Most diseases are caused by fungi that can live in the air as tiny spores, or be carried on diseased leaves. They can usually infect the plant in the rainy season when the spores germinate and the fungus can then grow into the leaf through the stomates. Another pathway of infection occurs when fungi and bacteria enter holes in the leaves, stem, corn and roots made by insects, nematode worms or other animals.
s for control of diseases include:
Select clean land with no wild bananas.
Keep land clean of weeds, dead leaves and trash.
Select clean suckers for planting material.
Plant in land that has a well grown cover crop.
Keeping the project clean of weeds, dead leaves on the ground, dead leaves hanging down from the plants.
Control rats and flying foxes.
Leaf Spot diseases
Leaf spot diseases Black Sigatoka disease, Sigatoka Leaf Spot disease and Black Leaf Streak disease caused by Mycosphaerella fijiensis, M. musicola, occurs in most banana growing regions. They cause the bananas to produce less fruit by destroying the leaves. Sigatoka disease starts as yellow streaks that darken to form elliptical brown spots. The whole leaf might die. The disease spreads rapidly if the banana project is not clean weeded and useless suckers not removed. Badly infected leaves should be removed and burnt. Fungicide spraying and use of fogging with mineral oils will help to prevent this disease. Other leaf spot diseases do not cause much damage, e.g. Cordana leaf spot Cordana musae, leaf speckle Mycosphaerella musae.
Wilt diseases
Panama disease, fusarium wilt is caused by the soil fungus Fusarium oxysporum. The fungus enters through the roots especially if damaged by nematodes. The plant cannot take up water and the leaves wilt. The cut stem has a fishy smell. There is no sanitary control or chemical control available, but the "Cavendish" clones are highly resistant to this wilt.
Bacterial wilt, moko disease is transmitted above the ground by insects or infected knives. It is similar to Panama disease except that it shows yellow lamina near the petiole. It can be controlled by burning diseases plants and disinfecting knives with formalin.
17. Fruit bunch
See diagram 51.17: Bunch
The fruit bunch appears at the top of the plant when it is about nine to ten months old. About 70 days after this the fruits begin to grow, and the bunch starts to get heavier. Two things need to be done when the bunch begins to develop:
A long piece of wood should be used to put under the stalk of bunch to support it. If this is not done, a strong wind may blow the plant down.
The large bud of the male flowers should be cut off about 15 to 20 cm below the bottom of the last flower, and this should be done two weeks after the first hand of flowers opens. If it is done earlier than this, the plant will lose too much sap. If it is done too late, much food will be sent down to this part that is not needed.
18. Harvesting
See diagram 51.18: Packing
1. You need a flowering stem with bananas.
Fruit develops about two months after the flowering stalk has pushed up. The flowering stem has grown up through the middle of the false stem turned down, and started to form two rows of flowers at each node, female flowers and later male flowers. The cluster of female flowers at each node will produce a hand of bananas. The male flowers are sterile and soon fall off leaving a bare stem. The end of the stem continues to grow even after the fruit has formed. Each cluster of female and male flowers is enclosed in a colourful bracket that is like a protective leaf. The young bracts at the end of the stem enclose each other to form a cone called the bell. The older bracts further up the stem turn back then an off. Leave 45 cm of the stalk above the fruit. This is used for carrying the bunch easily. It also holds some water that the fruit can use after cutting. Never leave the fruit in the hot sun. Always handle fruit very carefully to stop bruising and marking the fruit. Never let sea water touch the fruit. Bananas ripen best when they are picked green. If they are to be used for the home, cutting them down when they are fat is best, round and light green in colour. If they have to be taken in a truck or a boat to market, cutting them down when a little younger and the fruit are still a bit angular and not round is best.  The fruit ripens best in a dark, cool place. Take great care should be taken in harvesting bananas. If the fruit has to be packed into boxes, the hands must be removed and packed neatly in layers in the box, first one way, then the other. A little bit of stalk must be left on each hand so that the fingers of each hand stay together.
2. "Banana language"
"finger" - single banana fruit
"finger stalk" - stalk attaching the finger to the hand
"hand" - cluster of bananas from a single flower group at a node forming a section of the bunch
"bunch" - the whole flowering stem (inflorescence) bearing hands of several fingers of fruit
In marketing, a bunch may be called a "stem".
A bunch is ready to harvest when the fruit is full and round, the remains of the flowers should break off the end of the fruit when rubbed with the fingers. The fingers are plump, green and almost ready to turn yellow. Note the date when the first petal opens. Twelve weeks later, the fruit should be ready to be cut down. Use a bush knife to cut the bunch stalk high up to leave a long "handle". If the bunch is too high up, cut partly through the middle of the false stem to make it bend. Hang up the bunch by the false stem in a shady place for ripening. Show the students how to cut down a bunch and hang it in the shade to ripen fully. Cut down the tree after harvest.
2. The first generation tree will bear fruit once only then die to the ground so after harvesting there is no point in keeping the first generation tree. Cut the first generation tree down near to ground level and care for the follower crop in the same way as for the first generation crop. Show the students a flowering stem with bananas. Explain the different parts of the stem and the way the bananas are formed from the female flowers. Are the bananas ripe?
3. Cut open a banana. Note the six-sided fruit. Squeeze the banana and note the three parts of the fruit wall. The three rows of black spots are the remains of the seeds.
4. Bananas may have originated in Malaysia but in 327 BC Alexander the Great took some back Europe. Arab people took them to Africa and Spanish or Portuguese people took them to North America.
5. Bananas are a good source of dietary fibre, Vitamin C and potassium. A plain banana is less than 1% fat and 364 kilojoules per 100g.
When harvested when the fruit is mature but still green the banana is mostly starch and about 1% sugar. As they ripen the starch converts entirely to sugar.
If not to be eaten immediately, choose bananas with green tips. Solid yellow bananas are almost ready to eat and bananas with brown specks on the skin should be eaten immediately. Keep bananas at room temperature away from direct sunlight. Ripe bananas can be stored in the refrigerator to extend their shelf life. The skin will turn black but the flesh will be unaffected. The ideal refrigeration temperature is about 13oC. If stored below 10oC the thawed, spoilage increases because of increase phenol levels from breakdown of cell membranes. To assist ripening of green bananas put them in a paper bag with an apple or pear. If using fresh bananas in fruit salads squeeze lemon juice over them to prevent browning. Use very ripe bananas in muffins or  cakes.
6. In Australia, about 95 per cent of the bananas are the Cavendish variety, named after the British Lord cavendish who grew them in Kew Gardens. The red-tip or eco-bananas are a variety of Cavendish grown with a minimum of chemicals and the ends dipped in hot red wax. The smaller, sweeter Lady Finger bananas represent 4 per cent of the market. A similar variety is called Goldfinger. An interesting variety called Ducasse has superior flavour to other varieties and keeps its shape during cooking. However, the soft skin is speckled with a grey-white mould and by the time the banana is ripe the skin is black.
banana leave can be used for wrapping fish, meat or chicken to be steamed, poached, grilled or barbecued. The blossom can be eaten after peeling off the outer leaves. It can be cooked in curries or soups. Plantains, cooking bananas, have high concentration of starched so they must be cooked.
19. Costs, returns and profits
See 6.9.20.0: Understanding the records
Financial records terminology
"Returns" refers to the money you receive for a crop.
"Costs" refers to the money you pay for things to produce the crop. Costs are divided into production costs and establishment costs.
"Production costs" refers to the costs of items used in producing a crop, e.g. seeds, fertilizer, insecticide, tractor hire and cost of paid labour. Production costs include cost of planting material bought, cost of tractor hire, cost of fertilizer used, cost of insecticide used.
"Establishment costs" "Establishment costs" refers to the cost of items needed to produce the crop that lasts a long time and can be used to produce other crops, e.g. nursery, tools, fencing materials, buildings. Assume that items of establishment costs will last for five years. So for any one year, divide the establishment costs by five. "Profit" is how much money left when you take costs away from returns. Keep the following records:
A farm diary to record the dates and details of work done on the banana project.
Establishment costs, i.e. items purchase to do the work, but can be used again, e.g. spades.
Production costs, e.g. costs of freight charges, fertilizers and spray chemicals.
Returns, i.e. the date and how much money received when bananas are sold.
Profit
Profit = Returns - Production Costs - Establishment costs/5 Calculate the profit for the Banana Project after one year.
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.