School Science Lessons
2024-04-18
Pineapple Project
(PineProj)
Contents
Preface
1.0 Pineapple project
2.0 Plant parts
Bromelain
3.0 Soils for growing pineapples
4.0 Leaves
5.0 Roots
6.0 Flowering and forcing
7.0 Planning the pineapple garden
8.0 Planting material
9.0 Selecting plants for planting material
10.0 Planting
11.0 Pineapple growing
12.0 Keeping records
13.0 Fertilizers
14.0 Pests and diseases of pineapples
15.0 Weeds
16.0 Improving production
17.0 Pineapple varieties
18.0 Boron deficiency
18.0 Bromelain, C39H66N2O29
19.2.9.1 Pineapple jelly
12.0 Keeping records

1.0 Pineapple Project
Pineapple F180 variety, Daleys Fruit Tree Nursery
Dwarf Pineapple variety, Daleys Fruit Tree Nursery
Red Pineapple variety, Daleys Fruit Tree Nursery
Pineapple '73-50', Daleys Fruit Tree Nursery
Pineapple Project
Pineapple (Ananas comosus), evergreen, perennial herb, fast growing, fruit, large, yellow-orange, juicy, sub-acid, used fresh, canned, juice, propagation from ratoons, suckers, slips, crown,tuft of leafy bracts on the fruit, Tropical America, Bromeliaceae.
Ananas comosus is the only bromeliad, Family Bromeliaceae, that produces a fruit that can be eaten.
1.0 Show a ripe pineapple fruit.
Cut it into small pieces and taste it.
1.1 The scientific name for the pineapple plant is Ananas comosus.
Pineapples are in the botanical family Bromeliaceae, genus Ananas, species comosus.
Ananas is modified from the original South American name for the plant "nana", meaning fragrance.
The species name "comosus" means "long hair".
1.2 Pineapples are terrestrial herbs with very short stems bearing rosettes of long narrow leaves that may have spines.
The flowers of the dense terminal inflorescence stick together so that a fruit called a syncarp forms.
Above the inflorescence the main axis keeps growing to form a terminal crown of leaves.
1.3 The original pineapples from South Brazil and Paraguay spread to Central America and in the 16th century were taken to Asia and Africa by explorers.
Pineapples were introduced to the Pacific region in the 19 th century.
When Christopher Columbus brought the first pineapple to Spain in 1493, the Spanish thought it resembled a pine cone and called it Pine (pina), of the Indies.
The English called it an apple, because of its taste.
So the name "pineapple" is Spanish and English.
Commercial production of pineapples in order of amounts grown is as follows: Hawaii, Mexico, Cuba, Puerto Rico, Brazil, Nigeria, South Africa, Kenya, Taiwan, Philippines, Malaya, Australia.
2. Pineapples as food, pineapple chemistry.
Pineapples are high in sugar content.
When mature the yellow flesh of the fruit has 10 to 18% sugar and 0.5 to 1.6% acid.
The main food value is as a protective food, because pineapple contains useful amounts of vitamins A, B and C.
Pineapples can be eaten as fresh ripe fruit, peeled, sliced, cored and put into cans, crushed to make pineapple juice, used in cooking.
In some areas a pineapple wine is fermented.
Pineapples also contain bromelain, from the stem and juice, a mixture of protein-digesting and milk-clotting enzymes.
Chemicals in pineapples.
| calcium oxalate raphides | Furfural | n-Valeric acid | Vanillin | Bromelain | Cyanidin glucoside | Cyanin | Feruloylputrescine | Lutein.
3. Experiments.
* Add pineapple juice to milk.
The milk protein begins to coagulate and degrade as it reacts with the bromelain.
* Pineapple juice will also remove the gelatine emulsion surface on black and white photographic film!.
4. Pineapples will grow quite well on soils that are not very rich, but they grow better if given some fertilizers.
Pineapple plants can keep living through dry times.
Tops cut off fruit can be kept alive in the shade of a dry room for nearly a year.
5. A moderate rainfall of 1000 to 1500 mm is preferred for best growth, but pineapples grow well in heavier rainfall conditions, provided the soil is well drained and the area frost free.
The best environmental conditions are cool nights and sunny days.
2.0 Plant parts
| See diagram 60.2: Pineapple plant parts.
| See diagram 9.100.3: Pineapple fruit- coalesced berries.
The pineapple plant is a herbaceous perennial that grows to 1.5 m high and 1 m wide with a rosette of leaves around a terminal bud.
The sword-shaped leaves are long and pointed, arising in a rosette from a short stem.
Each leaf ends in a sharp spine and some cultivars have leaves with spiny margins.
The terminal bud produces a flowering stem that becomes an inflorescence of red purple flowers attached by a leaf-like pointed bract.
The pineapple has no seeds, because they develop fruit even if not pollinated and pineapple cannot self-pollinate.
Some wild pineapples do have seeds.
The pineapple fruit is a coalesced multiple fruit formed from the fusion of over 100 fruitlets embedded in an edible stem.
The ovary of each flower becomes a berry so all the berries squash together to form a single structure.
The tough waxy skin contains what remains of the pointed bracts and the flowers.
Dried herb is sold as pineapple fruit chips.
1. The plant consists of a main shoot and several side shoots.
The main shoot keeps growing straight up.
A shoot consists of a shoot apex or growing part and a stem.
The shoot apex, the "growing point", it is always growing upwards and never dies.
The fruit is formed in the stem when the shoot apex makes a flower bud instead of a leaf bud.
In the angle between the leaves and the stem are buds called axillary buds.
These buds may grow out into side shoots, suckers or slips.
The lower buds may grow into roots.
The phyllotaxy of the flowers and fruit based on contact parastichies (spirals coming out of their top), is 8 and 13.
In the most common variety from Hawaii, the Smooth Cayenne variety, there are two spiral arrangements:.
* Eight gently sloping spirals composed of every 8 fruitlets.
* Thirteen steeper spirals composed of every 13 fruitlets.
2. The fruit is coloured yellowish orange when it is ripe.
3. The butt is the main stem or stalk of the plant below the fruit.
4. The top is the small leafy shoot that keeps growing above the fruit.
This part makes the best planting material.
5. Suckers are large strong shoots, branches, from the main stem or butt.
The suckers come from axillary buds at the lower part of the butt.
Suckers may not grow at all if the plant has produced too many slips.
6. Slips are small leafy shoot branches that grow up from the upper part of the main stem or butt.
Slips come from axillary buds at the upper end of the butt, just underneath the fruit.
If the plant has too many slips, they take some food that could have gone into the fruit.
7. Roots grow from the bottom of the stem and the butt.
Also some roots may grow from the axillary buds low down on the stem.

3.0 Soils for growing pineapples
1. Pineapples grow well on some Pacific islands, but they will not grow well on coral soils.
Pineapples grow well in the lowlands and in the highlands to an altitude of about 1700 metres.
2. They grow best on the slopes of hills if the soils have come from volcanic, basaltic, rocks.
3. Most pineapple soils are not very rich; in fact most of them are poor soils that do not contain much plant food so pineapple soils.
need fertilizers.
4. Pineapples must have a soil with good drainage.
If the soil is badly drained the clay subsoil should be ripped up by tractors to loosen it.
5. The best place to plant pineapples is on a slope of about 40 degrees.
If the soil is flat, then the soil should be heaped up to make beds in line with the direction of maximum slope.
Because pineapples do not cover the ground well, rain may wash away the good topsoil.
To prevent this erosion occurring, pineapples should be planted only on flat or gently sloping land.
6. The best soils for pineapples are well drained, slightly acidic soils pH 4.5 to 5.5 with good drainage, high soil organic matter and.
high potassium, K.
Pineapples can tolerate high levels of Aluminium, Al3+, and Manganese, Mn2+.
Pineapples are very heavy feeders on foods in the soil, particularly nitrogen and potassium.
Plants that have been growing in the same area for a few years commonly have red leaves, because nitrogen is scarce.
Yields will start to decrease and fertilizer must be applied to increase the yields again.
Plant material applied as a mulch can also provide food for the crop.
If waste material from other crops is available, this can be spread over the ground as a mulch to keep down weed growth.
In some countries paper or black plastic is laid on the ground to prevent weed growth.
Perhaps the best method is to plant the pineapples under the shade of another crop, for example bananas, so that the weeds will be shaded.

4.0 Leaves
See diagram 60.4: Pineapple leaves.
1. The leaf is long, up to 100 cm, and ends in a point.
The leaf is curved upwards on the side facing the stem.
The back of the leaf is rounded.
Spirally-arranged sword-like leaves with pointed tips may be with or without spiny margins.
Two main varieties: 1. rough leaf variety has spines on leaves and good fruit, and 2. smooth leaf variety has spineless leaves and larger, but not so tasty fruit.
Unripe fruits may have a stinging effect on the tongue.
Some varieties have smooth leaves that contain water storing tissue.
Other varieties have spines.
You need gloves to handle the spiny leaves which may contain an irritant sap and cause dermatitis.
2. Cut across a leaf with a sharp knife to see that the thickness of the leaf has two parts:.
the dark green food-making part, and the lighter coloured water-storing part.
3. Look at a whole plant from the side to see the angle of the leaf to the stem is greatest with the lower leaves and smallest with the top leaves.
4. Find two leaves in line one above the other.
The pineapple leaves grow very closely together.
They are joined in a spiral to the stem.
Usually every 13th leaf is directly above another leaf lower down.
There are usually 5 spirals between the 2 leaves that are in line.
5. The older leaves of pineapples do not drop off as with many other plants.
6. Count the total number of leaves on one plant.
When the pineapple plant makes a fruit there are usually from 60 to 80 large leaves formed.
7. The largest leaves are usually found at the top of the plant.
The largest and most recent leaf to mature is called the "D leaf".
This is the highest leaf on the plant and it stands nearly straight up.
8. The leaves are made by the shoot apex, growing point.
Select a top that has been cut off a fruit.
Use a sharp knife to make a cut straight down through the middle of the top.
Look at half the top to see how the shoot apex makes the leaves.

5.0 Roots
Dig up one plant so the roots can be seen.
1. Most of the roots come from the bottom of the stem or butt.
Other roots often grow from the axillary buds of the lowest leaves.
These roots are called axillary roots.
2. Pineapple roots usually grow sideways for one to two metres and grow down about 85 cm.
3. Measure the thickness of some roots.
4. Dig up some roots growing at one side of a plant and see how far sideways they grow.
5. Dig a small hole straight down to find if there is a hard layer of subsoil there that might stop the roots going down.

6.0 Flowering and forcing
See diagram 60.6: Pineapple life cycle.
1. When the pineapple plant is big enough, the shoot apex makes flower buds usually when it has 60 to 80 leaves about 14 months after planting.
The flower is an inflorescence of 100 to 200 flowers with three fleshy sepals and petals, six stamens, and the ovary in 3 parts.
The fruit is a cylindrical, compound fruit formed by fusion of berry-like fruitlets.
The leafy shoot at the apex called the crown.
2. The making of the flower buds is called "flower initiation".
The flower buds turn into the fruit that is really a big flower.
The fruit is many individual berries fused to the central stalk.
So the "fruit" has leaves on top due to the continued growth of the stalk beyond where the berries are attached.
3. After 4 to 5 months post initiation the fruit is ready.
4. Suckers planted in November to December will start growing about December the next year.
The fruit will be ready during April to June the next year after that.
5. Suckers planted in March to April will initiate in April to June the following year.
The fruit will be ready in September to November.
6. If a field of pineapples can be made to produce a crop simultaneously, repeated labour harvests are avoided.
Growers learned to use ethylene, acetylene or the plant hormone auxin to bring all plants to flower together.
The process is called "forcing" or "closing out", or "induction".
Nowadays, the growth regulator ethephon, an ethylene releasing compound, is sprayed onto pineapple plants to promote uniform flowering.
Pineapple fruits usually mature at certain times of the year so that there are times when pineapples are not available in the markets.
By using these ethylene-releasing compounds or flowering hormones, pineapples can be made to fruit earlier than they would have naturally.
Also it can make all plants in one area fruit together so that operations like harvesting and de-suckering can be carried out more easily.
7. Apply forcing to plants when they look big enough to carry fruit, depending on the type of planting material and growing conditions.
If applied too early, small sized fruit will result.
Mix a few drops of the forcing solution with water then pour into the heart of the plant, e.g. fifty drops for half a bucket of water, 4.5 litres is enough for 75 plants.
After applying the forcing solution, fruit should be ready for harvesting from rough leaf pineapples in 22 to 24 weeks, and for smooth leaf pineapples in 26 to 30 weeks.
Ask an agriculture extension officer for help with forcing.
One recommendation is to use 0.5 Kg Ethephon, 80 Kg urea for absorption, Na2CO3 for pH increase to 9.0, 2 250 to 3 000 litres water per hectare.
Forcing with growth regulators is most effective during cooler seasons.
Hot weather is not good for good floral induction.
During hot seasons, when night temperatures are greater than 25oC, do not use nitrogen (N), fertilizer for four to six weeks before forcing to improve flower induction.
7.0 Planning the pineapple garden
| See diagram 60.7: Pineapple garden beds.
1. Plant pineapples early in the year where there is a little slope so that water will run away from the planting material.
Pineapples will not grow well if the soil in that place is too wet, or if there is bad drainage.
The soil on the slope may be a better red volcanic soil.
The slope must not be too steep, because rain washing down may cause soil erosion and the soil will be lost.
2. Build up beds 60 cm apart and 30 cm high with the plants at least 30 cm apart in the beds.
Pineapples can be planted in rows, or individually.
One system has two rows planted next to each other, 60 cm apart, and with 30 cm between plants within rows.
A distance of 1.8 metres is left between the centre of one double row and the centre of the next.
If bananas are also grown and if the spacing between these is about 4 m × 2 m, then there is plenty of room to plant double rows of pineapples between the rows of bananas.
To give 100 students a reasonable sized piece of pineapple (say 200 gm), once per week, about 800 plants would be required.
At the recommended spacing, using double rows, this would take an area of about 220 square metres, 22 m × 10 m.
If pineapples are grown under the shade of bananas, the area required to give a supply of bananas to 100 students was 30 m × 20 m.
If pineapple were grown in the spaces between these bananas, there could be enough room for about 850 plants.
Commercial production may use rows 60 cm apart within beds and plants 28 cm apart within rows, a total of 75 000 plants/Ha for the fresh pineapple market.
3. Before land is used for the next crop, all old pineapple plants must be dug up and burnt, because old plants may have diseases or pests, e.g. mealy bugs.
After marking out the pineapple garden area mark the corners of the plot with stakes.
A suitable garden may measure 65 m wide by 10 m long.
This would give us enough room to have five rows each about 10 m long.
After marking out the area, dig the area and form it up into separate gardens.
Pull out all the weeds.
New land must be well cleared then dug to a depth of 30 cm and any leaves or grass left to rot.
The crop does not cover the ground well so the soil is exposed to the sun and weed growth can be vigorous.
Weeds must be controlled so that a good crop can be obtained.
Weeding with a hoe or a grass knife is the usual method.
Chemicals that kill the weeds, but do not affect the pineapples can be used, e.g. Diuron, dissolved in water.
4. Sprinkle some mixed fertilizer over the soil on the beds.
A fertilizer mixture that contained nitrogen, phosphorus, potash, magnesium and some zinc and iron can be used.
After mixing the fertilizer well, spread over the soil at the rate of about 150 gm per square metre of bed.
Also spread some insecticide, e.g. heptachlor, over the soil to kill mealy bugs.
Take great care to avoid getting any of this chemical on the hands.
Ask an agriculture extension officer to show you how this must be done.
8.0 Planting material
See diagram 60.8: Pineapple plant.
Commercial pineapples are not grown from seed.
Commercial cultivars from Hawaii and the West Indies are self sterile.
The tiny flowers cannot be fertilized.
Pineapples are reproduced by vegetative propagation, using crowns, slips, or suckers.
The 5 types of planting material used are as follows:.
1. Tops or crown is the leafy vegetative shoot that grows on the top of the fruit.
Plants that grow from tops take longer to fruit than those grown from suckers and slips.
They are the best kinds of planting material, especially if they are large and come from a plant that had a big fruit.
Planted year round they 2 years to produce fruit or can be forced 9 to 13 months later.
Plant crop duration is 15 to 20 months in cooler areas and 11 to 14 months in warmer tropical areas.
2. Aerial suckers are leafy branches carried on the stem above ground level.
Plants grown from aerial suckers produce fruit more quickly than other sorts of planting material, and yield lots more fruit.
3. Suckers or ground suckers are leafy branches or side shoots that arise from axillary buds of the leaves on the stem at or below ground level.
Suckers are very good planting material.
They are usually the heaviest kinds of planting material, and may weigh as much as 1 kg each.
They grow faster and may make a fruit after 18 months.
They can make a second crop or ratoon crop of fruit.
However, suckers may not grow very strongly if there are many slips, because slips take all the food from the leaves.
Plants may have 6 to 12 slips, but plants with many slips will not sucker until the slips are removed.
Some plants never make any suckers.
Suckers take 17 months to produce fruit.
4. Slips are the leafy side shoots carried on the fruit stalk that come from axillary buds just below the fruit.
It is good if there are no more than four slips on each plant, and best if there are only two slips.
If there are too many slips on a plant, it is best to break them all off using a forked stick.
Also, cut the growing point or shoot apex so that this plant can never be used to supply planting material.
If it were used, the new plants would also make too many slips.
Plants from slips take 20 months to produce fruit.
6. The butt is part of the stem below the fruit.
This can be used as planting material, but it grows very slowly and is not often used.
Butts or ratoons are the stems of the plants that can be used for planting after the fruit is harvested.
The base of the stem and the fruit stalk are cut away and the leaves are removed.
Plants grown from butts are very slow to produce fruit and do not yield very well.
Propagation is by crowns and slips for commercial production and ground suckers and suckers for non-commercial production.
All this material needs to be prepared for planting by stripping off the leaves at the base to allow it to dry in the sun for a few days to help a vigorous root system get established.
9.0 Selecting plants for planting material
1. If the best plants are used for planting material, the plants will produce bigger fruit for better prices.
2. The food made by photosynthesis in the leaves goes up the stem to be used to make the fruit, slips and suckers.
Plants that make the best pineapples have a big fruit and no more than two slips.
Poor plants have six to seven slips and may not make any suckers.
So do not take planting material from plants that have four or more slips to each plant, because they will grow into poor plants where most of the food goes into making the slips,
and not into the making of fruit and suckers.
3. Look at many pineapple plants to find the following:.
3.1 some plants with only two or three slips and,
3.2 plants with many slips.
Find any suckers on these plants.
4. Select plants that make strong suckers quickly, because these will grow into a strong following crop.
Good planting material comes from a healthy plant with big well formed fruit.
The plant should have only two or three slips.
Tops are the best planting material, because they are nearly always the same size so they grow evenly and make fruit simultaneously.
The next best are big slips especially if the plan has few of them.
Planting material should all be about the same size and weight, otherwise the fruit will ripen at different times so you cannot send it away to be sold, because some fruits are not ripe.
Also, if you use a hormone to make the plants form a fruit some plants will be too small and the fruit will be too small to be sold.
10.0 Planting
1. Before planting, break off a few leaves from the bottom of the planting material and leave it in the shade for a few days.
Dig the surface of the garden lightly.
Lay out the planting material on the ground and check that each bed has only one kind of planting material in it.
Plant different kinds of planting material in different beds to see the difference in the way they grow.
2. All the planting material in any one bed should be about the same weight.
Discard and burn any poor planting material.
3. After planting, the soil must be pushed down firmly around each planting piece.
Water the planted pieces.
11.0 Pineapple growing
See diagram 60.11: Pineapple fruit.
1. After planting the stem grows up and the growing point, or shoot apex, makes new leaves.
2. When the shoot apex has 60 to 80 leaves it then makes a flower bud.
This is called "flower initiation".
3. The flower becomes a small pineapple fruit that grows bigger.
After four months the fruit is ready to pick.
4. The shoot apex at the top of the fruit then keeps on growing and makes the "top".
Axillary buds in the leaves growing from the butt turn into "slips" (high up), or "suckers" (low down).
When the fruit is still forming, use a forked stick to break off all the slips on plants with more than two or three slips.
5. Time to maturity differs with different planting materials.
Plants grown from aerial suckers produce fruit first, then ground suckers, then slips, then tops, with butts taking the longest time to maturity.
A crop from aerial suckers will produce fruit in a year.
6. Harvest as shell colour changes from green to yellow at base.
Pineapples are non-climacteric fruits, because they do not ripen after harvest.
Pineapple fruit quality is at its best only if the fruit matures on the plant.
They do not become sweeter if harvested earlier since there are no starch reserves to be converted to sugar.
The sugar content must come from the rest of the plant.
Pineapples do not store well and should be eaten soon after harvesting.
12.0 Keeping records
1.16 Records.
Keep the following records:.
1. Date of making garden.
2. Date of planting pineapples.
3. Height of plants each month and number of leaves made.
4. The number of months when the plant seems to have made a flower/fruit bud.
5. The number of months for the flower bud to turn into a ripe fruit ready to pick.
6. The number of months before the first slip is made.
7. The number of months before the first sucker is made.
8. Rainfall during the project.
9. Cost of items bought for the pineapple project.
13.0 Fertilizers
1. The most important plant foods are nitrogen, N, phosphorus, P, and potassium, K, so a mixed fertilizer should contain these substances.
However, it should also include other elements, e.g. zinc, Zn, and iron, Fe.
Fertilizers must be applied at the following times:.
1.1 Before planting, mixed fertilizer.
1.2 Three weeks after planting, ammonium sulfate spread down the middle of the bed between the planting materials.
1.3 Seven weeks after planting, a mixed fertilizer containing urea, iron sulfate, zinc sulfate.
At this time some Diazinon should also be spread on the soil to stop mealy bugs.
1.4 Twelve weeks after planting, a mixed fertilizer, NPK 10-1-15.
1.5 Twenty weeks after planting, same as for 7 weeks.
1.6 Thirty weeks after planting, same as for 7 weeks.
1.7 Thirty weeks after planting, a mixed fertilizer NPK 10-1-15.
1.8 Forty-four weeks after planting, ammonium sulfate only.
1.9 Forty-eight weeks after planting, mixed fertilizer NPK 10-1-15.
2. Ask an agriculture extension officer how much of these fertilizers to put on the soil each time.
If fertilizer is to be added, a mixture high in nitrogen and potassium should be used.
Four bags of urea (200 kg), and two bags of muriate of potash (100 kg), would be for a hectare of plants in a year.
For 500 m2, 10 kg of urea and 5 kg of muriate of potash would be sufficient.
This amount should be applied in three or four applications throughout the year.
14.0 Pests and diseases of pineapples
| See diagram 60.14: Mealy bugs.
| See diagram 60.12: Mealy bugs.
1. Ask an agriculture extension officer to help you decide what chemicals to use and how to use it.
Be very careful if students handle these chemicals as they are poisonous.
Dig up and burn all old pineapple plants at least six months before planting new material.
Treat the soil with a chemical like diazinon before planting pineapples.
Treat all planting material with recommended chemicals before it is planted.
Treat the soil around the growing crop with chemicals to kill the bugs.
Some bugs may live at the base of the leaves, but spraying the leaves does not stop the disease, because most of the bugs are under the ground.
2. The mealy bug (Dysmicoccus brevipes), causes mealy bug wilt, the most serious disease of pineapple.
However, mealy bugs are "ant-attended", so using a recommended insecticide to kill the ants helps control the mealybug.
All crowns and suckers could be treated with diazinon and let dry before planting.
The mealybug is a small white insect that can often be seen on the fruit or at the base of the leaves.
This small animal lives mostly under the ground and feeds on the roots.
It carries a disease called mealybug wilt virus that infects the pineapple roots.
This makes the roots stop growing, become soft and then rot.
If they are a problem in a particular area, planting material should be dipped in a solution of malathion, e.g. add 25 mL malathion + 50%, miscible oil to 10 L of water.
However, using insecticide against mealy bugs may destroy their natural enemies! 3. Pineapple wilt disease, caused by a fungus, can be treated in the same way as mealy bug.
If you look at the roots and you cannot see any mealy bugs.
However, if the roots are rotten, then it may be the root rot disease caused by the fungus.
It only grows in soils that do not have good drainage so doing anything to stop this disease may not be possible until the ground is cleared for the next crop.
Then either give the soil better drainage or leave this soil and move the garden to a better place.
Phytophthora causes top and root rot of pineapple.
Root rot caused by Phytophthora cinnamomi can be controlled by a pre-planting application of sulfur to lower the soil pH below 3.8.
Pineapple crop losses caused by root rot may soon be a thing of the past, thanks to new research on environmentally friendly biofungicides at The University of Queensland, led by molecular plant pathologist Dr Anne Sawyer, who targets the pathogens that cause infected pineapple plants to wilt and die.
She is developing biofungicides to combat pathogens that affect pineapple, avocados, and native Myrtaceae tree species.
These pathogens include Phytophthora cinnamomi, a fungal-like organism transmitted through soil that causes root rot.
“Phytophthora causes rotting of roots and anthocyanescence (reddening or purplish coloration) of foliage."
Dr Sawyer, with Professor Neena Mitter and Prof. Zhi Ping (Gordon) Xu, pioneered development of non-toxic RNA-based sprays, known as "BioClayTM", to prevent a range of agricultural diseases and threats.
“These new biofungicides are designed to improve fruit quality, boost production efficiency, and reduce the use of chemicals in food production,” she said.
“BioClay uses a gene silencing technology that is precise and specific in the way it helps plants defend against pathogens.
“It is an environmentally sustainable alternative to chemical pesticides and leaves no residue on the produce.”
15.0 Weeds
1. Weeds are any plants that are growing where you do not want them to grow.
Weeds have the following bad effects on pineapples:.
1.1 They take soil water from the pineapples.
1.2 They steal plant food from the pineapples.
If you put some fertilizers on the soil, some of these plant foods will be used by the weeds.
1.3 Weeds may also take light away from the pineapples by shading them.
1.4 Sometimes strong growing weeds may take living space from pineapples.
2. You can kill weeds by digging them out by hand.
This can be done in a small garden, but cannot be done if many pineapples are being grown.
3. Some weedicides can kill grown weeds.
Others are called pre-emergent weedicides, because they kill the weeds when they have only just come through the soil.
Weedicides like Bromacil, Ametryne and Diuron are pre-emergent weedicides.
16.0 Improving production
1. At the end of the project it is a good time to think of how production of pineapples could be improved, e.g. better selection of good planting material, because far too many poor plants are
growing, too many mealy bugs, too many weeds growing, not enough fertilizers used.
A very common mistake in pineapple growing is to leave the plants growing in the same position for many years.
After a plant has produced a fruit, it will not produce another one.
Instead, one or more of the sucker plants that grow out from the mother plant will carry a fruit.
If all the suckers are left on the other plant, only small fruit will be produced.
2. After a fruit has been harvested the mother plant must be cut off and only one sucker left.
The other suckers must be removed and soil heaped around the base of the remaining sucker so that the roots can obtain food easily from the soil.
This is called ratooning and will produce a ratoon crop.
Each plant propagated produces one fruit at the top of its stem.
This high quality fruit is called the plant's crop.
After the fruit is harvested, several suckers develop and one year later produces the ratoon crop.
The fruits are smaller and of lesser quality.
A second ratoon crop can develop after the first crop is harvested.
After that, the field is dug up and replanted.
When this has been done twice, that is when three fruits have been harvested from one planting, it is best to remove the crop and replant.
This is, because the fruit becomes smaller with each ratoon crop.
Large fruit will be obtained again after replanting.
3. It is best to plant the new crop on new ground and plant a different crop on the old area, or allow it to rest for a few years.
This helps to prevent a build up of weeds, insect pests and diseases in the area.
Planting can be done at any time of the year provided sufficient planting material is available and the soil is not too dry.
1. To improve pineapple production:
Know how to choose better planting material.
Take care with weeding and stopping pests and diseases.
Giving pineapples enough fertilizers of the right kind.
Handle fruit carefully.
2. Use the following:
digging tools, spades,
hoes for weeding and shaping beds,
fertilizers, as recommended by an agriculture extension officer,
chemicals for killing mealy bugs, as recommended by local agricultural officer.
flower-inducing chemicals or plant hormones, e.g. NAA, as recommended by an agriculture extension officer,
weedicides, as recommended by an agriculture extension officer.
17.0 Pineapple varieties
The first Australian pineapple varieties were introduced around 1858 from England.
The Smooth Cayenne variety was favoured, because it was a large soft flesh variety, high in acidity and grew easily under Australia's harsh conditions.
This variety was perfect for canning and through summer still had good eating characteristics as fresh fruit.
However, its inconsistency caused pineapple sales to stagnate and consumers to turn away.
So new varieties were bred in Australia:.
1. Rough Leaf variety has prickly leaves on the crown of this fruit.
Grown in tropical north Queensland, it has firm, attractive yellow flesh and an often preferred flavour when compared to Smooth Cayenne variety.
Production and availability of this fruit has declined, because of the increasing availability of new fresh fruit varieties.
2. Aussie Gold variety, a modern low acid variety originally from Hawaii, is best grown in spring and early summer.
It has a sweet aroma and may be chopped up and eaten fresh, perfect for snacking, fruit salads or fruit kebabs for kids.
3. Aussie Jubilee Australia, bred in Australia, is best grown from April through to October.
It is sweet and aromatic, low in acid, high in vitamin C and also higher in anti-oxidants than other varieties.
It is suitable for all occasions, as a fresh snack, in salads, will compliment any recipe and is best known for its aromatic flavour.
It is suitable for children being sweet, with low acidity and double the vitamin C of other pineapples.
4. Aussie Smooth Cayenne variety has the traditional pineapple flavour, with soft, juicy flesh, and perfect for summer juices, fruit salads, and has a sharper flavour for cooking.
It is higher in acid through winter and seasonally is best through summer when the acid levels drop.
It is still a popular variety in Australia as it has a dual use for both fresh market and canning.
5. Aussie Festival variety is the latest variety in the pineapple breeding programme.
It is said to taste like a Pina Colada with sweet coconut aromatics in the summer.
It is a large pineapple in the early stages of development, but is expected to be a favourite with consumers and farmers alike.
The good sized fruit and other traits mark Aussie Festival variety as a very promising summer season variety.
The time to harvest is three weeks later than other varieties, so it extends the peak summer harvest into February to April, when other pineapples are in short supply.
18.0 Boron deficiency.
Boron deficiency in soils: 1.1.0.
Boron deficiency in pineapple, causes fruitlets to separate and the gaps between them become corky.
Root growth is poor, but only when the deficiency is severe does the growing point die or the leaves show symptoms.
18.0 Bromelain, C39H66N2O29
Commercial: Carbohydrate moiety of bromelain, C39H66N2O29, Bromelain, Technical Grade,, a carbohydrate allergen
Bromelain, bromelin, glycoprotein, a branched amino hexasaccharide, antiinflammatory, mixture of proteolytic enzymes from the two sources are distinguished as fruit bromelain (acidic), and stem bromelain (glycoprotein), extract formerly listed as EC 3.4.22.4, antiinflammatory, irritant, used after bruising and surgery, used to treat burn tissue, used to chill-proof beer, used commercially as a meat tenderizer, may be used to treat indigestion.
It occurs in extract from pineapple stem in mixture of compounds.
It has protein-digesting and milk-clotting enzymes in fruit juice and stem, but ess bromelain in the fruit.
It is used to reduce inflammation, e.g. bromelain tablets used to treat black eye, but avoid bromelain if taking aspirin or blood-thinning anticoagulants or if allergic to pineapple.
Pineapple juice will remove the gelatine emulsion surface on black and white photographic film!
See diagram: Carbohydrate group of bromelain.
Experiment Add pineapple juice to milk.
The milk protein begins to coagulate and degrade as it reacts with the bromelain.
Preface
Before teaching this project, discuss the content of the lessons with an agriculture extension officer 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 an agriculture extension officer.
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.