School Science Lessons
Food Gardens 2
2019-02-04
Please send comments to: j.elfick@uq.edu.au

Websites
Table of contents
Preface
9.12.0 Crop care, fertilizing, mulching, watering, weeding, harvesting
9.10.0 Multiplying plants, vegetative reproduction, seeds, sexual reproduction
9.8.0 Planting crops

9.12.0 Crop care, fertilizing, mulching, watering, weeding, harvesting
Crops and farming (Websites)
9.12.0 Crop care
9.12.3 Fertilizing, top dressing and side dressing
9.12.8 Harvesting
9.12.4 Hoeing
9.13.0 Mulching soil
9.12.7 Plant protection
9.12.6 Staking
9.12.2 Thinning
9.12.5 Watering and drainage
9.12.1 Weeding, weed control

9.10.1 Cuttings
9.10.1 Cuttings
9.89 Commercial rooting powders for stem cuttings
9.90 Leaf cuttings
9.88.1 Plant growth regulators
9.91 Root cuttings, phlox, hollyhocks, wild cherry
9.92 Stem cuttings, top cuttings, geranium, poppy, fuchsia, chrysanthemum, blackcurrant.

9.10.6 Grafting
9.10.6 Grafting
9.93 Bud grafting, orange, rose, fruit trees, apple, pear, plum
9.94 Whip and tongue grafting, citrus fruit and ornamental trees.

9.13.0 Mulching soil
9.13.0 Mulching
6.36 Mulch saves water (Primary)
5.38 Mulch garden soil (Primary)

9.10.0 Multiplying plants
9.10.0 Vegetative reproduction
9.10.1 Cuttings
9.10.2 Division
9.9.0 Seeds, sexual reproduction
9.10.3 Stooling
9.10.4 Layering
9.10.5 Marcotting, air layering
5.16 Planting material
9.97 Roots from plant parts

9.8.0 Planting crops
Horticulture (Websites)
9.8.0 Planting crops
3.3 Digging the ground
9.8.6 Companion planting
9.8.2 Grow your own seed
9.8.1 Imported seed
9.8.5 Interplanting
9.8.4 Pot plants
9.98 Potting mix
9.8.3 The four methods of planting:
9.8.3.1 Direct planting of seeds and cuttings
9.8.3.2 Planting in a seed bed.
9.8.3.3 Planting in seed boxes
9.8.3.4 Planting in a plant nursery
3.4 Planting methods, direct planting, seed beds, seed boxes
3.5 Planting seeds
9.8.7 Transplanting

9.9.0 Seeds
Plant nurseries, fruit trees, seeds (Commercial websites)
5.27 Germination test (Primary)
9.9.0 Seeds
9.9.2 Depth of Sowing
5.14 Seed, Parts of a bean seed
5.15 Seed germination
5.28 Seed sterilization

3.3 Digging the ground
Teach the students to explain the importance of digging the ground.
Digging the ground before planting allows seeds to germinate easily and quickly, allows roots to penetrate the soil easily, improves the
plant nutrients in the soil, and helps to control weeds and insects.
Good preparation of ground does need hard work, but later the crops will grow better and less work will be needed to look after them.
If beds and ridges run North-South, then all the plants in one row get the same amount of light.
Their shadows fall on the inter-row area and not on each other.
Do the practical work of preparation of ground soon after the lesson.
You may need other lessons to teach about raised beds or ridges.
1. Teach the students the need for good preparation of ground,
1.1 to loosen the soil so roots can grow easily,
1.2 to make a fine even seed bed so seeds will germinate easily and quickly,
1.3 to control weeds and insect pests by digging them up,
1.4 to improve the soil by mixing in dead plants and compost.
This will increase plant nutrients in the soil and make the soil easier to dig.
1.5 to form the soil into raised beds or ridges so it is ready for planting.
2. The steps in preparing the ground are:
2.1 turn the ground over to a depth of 15-20 cm.
Work backwards using spades for turning and hoes for breaking up clods of earth.
Dig out a trench and put the soil near.
6. Turn the soil one into the trench, then turn 2, 3, 4, five and put the trench soil into 6.
Dig in compost or other fertilizers.
Use rakes and hoes to make the soil fine and flat.
7. Each student is given a small part of the garden to dig up and keep clear of weeds until sowing.

3.4 Planting methods, direct planting, seed beds, seed boxes
Teach the students to explain the importance of three methods of planting.
The three main methods of planting:
1. Direct Planting of seeds and cuttings.
The soil should be prepared and fertilized two weeks before planting.
Planting must be done at the correct depth and correct spacing.
The seeds must look fat and healthy.
They should be planted in furrows or holes, singly or plant two seeds per hole and destroy the smaller seedling.
Cuttings may be planted singly but there are many different methods.

2. Seed bed.
This consists of a seed bed of specially mixed soil sheltered by a leafy roof.
The soil is a mixture of two buckets of sieved good soil and one bucket of rotten compost.
The mixture should be sterilized to kill weeds, pests and diseases by heating in a drum oven.
Seedlings may need thinning out and the plants should be hardened by not watering, and by gradually removing the roof a few weeks
before transplanting.
Select the strongest plants for transplanting on a dull afternoon and water the transplants well.

3. Seed boxes.
The boxes are about 24 x 24 x 15 cm and are kept on shelves in greenhouses, with a roof of sticks or leaves or artificial shade,
e.g. "Salon".
The soil in the seed box is sterilized before the seeds are planted.
They are planted in regularly spaced holes.
Very tiny seeds are usually mixed with a little dry sand before sowing.
The sand spaces the seeds well.
Another way is that small seeds may be sprinkled along a shallow drill, and when the cotyledons have just opened the seedlings are
transplanted into a second box with regularly spaced holes in the soil.
This is called pricking out.

Other methods include the use of pressed plant matter called Jiffy Seven pots.
They are stood in a shallow tray to take up water and can be transplanted without damaging the plants.
Another technique is to collect beer cans, half fill with soil mixture and use one for each seed.
Hardening off and transplanting is the same for both types of seed beds.
Seeds and other planting material can be planted in:
1. Long deep grooves in the raised bed or field called furrows.
Use a hoe to make them.
2. Short shallow grooves in the seed bed called drills.
Use a rake handle to make them.
3. Hills or mounds to allow drainage for sweet potato, maize and pumpkins.

3.5 Planting seeds
Teach the students to sow seeds correctly
The depth of sowing of seeds is usually printed on the packets of imported seeds.
For your own seed the best rule is that the seed should be sown at a depth of at least two cm, or at a depth of three times the width
of the seed, but not more than 8 cm.
You can set up some interesting trials comparing the germination of seeds soaked and unsoaked, and at different depths in the soil.
If seeds are sown too shallow they may be uncovered by the wind, eaten by birds or rats, or the roots will not grow properly.
If seeds are sown too deeply, the plant may become exhausted and be unable to push above the soil.
Sometimes students will dig up sown seed of plants, e.g. peanuts and eat them.
This is a problem of student discipline but it can be quite dangerous if the seeds have been treated with fungicide.
If they are direct planting, always dig the soil one month before planting seeds.
About two weeks before planting, dig in rotted compost, wood ashes or fertilizer.
Ask an agricultural officer which fertilizer is suitable.
For thinning, small weeds can be dropped into the furrow close together, then later the weaker ones can be destroyed to leave the
stronger ones growing at the recommended spacing.
Another method of thinning is to plant a group of seeds in shallow holes at the correct distance, and when the plants are three cm high
destroy all plants except the biggest ones.
The advantages of sowing seeds direct into the soil are that it saves time and does not damage the roots during transplanting.
1. Explain to the students that there are two dangers for a seed
1.1 The seed may dry out.
Then it may not germinate because it has no water.
We can stop this danger by covering the soil very lightly with some powdered animal manure or leaf mould.
It also helps if we mix some sand with the topsoil because this sand will keep the soil open and let rain in.
1.2 The other danger is that seed may get too wet.
Then it may be attacked by a fungus called the "dampening off" fungus.
We can stop this fungus by putting sand in the top soil.
This sand will let much rain drain away quickly.
The general rule about sowing seed is to plant it shallow.
Planting too shallow is better than too deeply.
2. Draw a diagram on the chalk board of seed planted correctly and incorrectly, too deep, too wet, too dry.
3. Take the students to the garden to practise the correct planting of seed.
4. Give each student 10 seeds to plant.
After planting ask the students to describe how they planted their seeds.
Record on the chalk board how many seeds grew for each student.

5.14 Parts of a bean seed
See diagram 9.113: Soaked bean seed
Two days before the lesson put some bean seeds in water.
Use enough seed for each student.
Also, have one dry bean seed ready for each student.
Leave the bean seeds in water in the classroom so the students can observe the seed coats swell and become wrinkled, then later
become smooth when the insides of the seed swells.
Give each student a dry bean seed.
See the hard shiny seed coat, the scar where the seed was originally attached to the fruit, the tiny hole (micropyle) at the end of the scar
to let water and air in.
The baby root (radicle) grows out through this hole.
Give each student a bean seed soaked in water.
The soaked seed is larger and softer because water has gone through the tiny hole.
When the water goes into the seed coats, they are first wrinkled and later smooth when the whole seed swells.
Cut open the seed coat with a finger nail or razor blade and see the baby plant inside.
The two main parts in halves are the cotyledons swollen with stored food.
Between the cotyledons is the baby shoot (plumule) and the baby root (radicle).
Tell the students to draw their seeds or draw the diagram.
Seed coats (outside), scar, hole (micropyle)
Baby plant (embryo)
Baby plant shoot (plumule)
Baby plant root (radicle)
Seed leaves (2 cotyledons) (store of food).

5.14 Seeds, revision questions
What are the two things you can see when you look at the seed coat? [Scar and hole called micropyle]
What are their functions? [The scar was where the seed was attached to the ovary wall.
The micropyle lets water and air in, and the radicle (first root) grows out through the hole.]
What are the three parts of a newly formed seed? [Baby plant (embryo) seed coats, food store in the cotyledons]
What are the three parts of a baby plant? [The shoot called the plumule, the seed leaves called the cotyledons, the root called the
radicle]
When you put a bean seed in water why does the seed coat first become wrinkled? [Because water soaks into it and makes it swell.]
Why does the seed coat later become smooth? [Because water then soaks into the inside of the seed, which swells and pushes out the
wrinkles.]

5.15 Bean seed germination
See diagram 9.113.2d: Bean seeds germinating
Two weeks before this plant 5-10 bean seeds at different levels as the diagram.
This can be done behind a piece of glass or in a glass aquarium, but keep the seeds in the dark.
Before the lesson, dig up germinated bean seeds at different stages of germination.
In the type of germination in the diagram, called epigeal germination, the cotyledons come out of the ground.
In the other type of germination, hypogeal germination, the cotyledons remain below the ground.
Show the students the seeds at different stages of germination.
Seeds are alive but they breathe very slowly.
When a seed is placed in the damp ground and water enters the hole the seed becomes very active, breathes more quickly and a new
plant starts to grow.
This is called germination.
The baby plant uses the stored food in the seed until it can produce green leaves and make its own food.

Stages in germination of a bean seed:
1. The seed swells and the radicle (baby plant root) grows out the hole in the seed coat.
2. The stem below the cotyledons grows into a loop.
3. This stem straightens and the cotyledons and the first leaves are pushed up out of the ground.

Conditions for good germination are as follows:
1. Water,
2. Air to let the baby plant breathe,
3. Healthy seed,
4. Correct depth of planting,
5. Correct variety kind of seed for tropical countries.

The problem of poor germination is usually caused by sowing seeds too deeply, or over-watering or under-watering.
If the seed is planted too deeply, the tiny developing plant exhausts the food supply in the endosperm
long before the shoot and leaves have broken through the soft surface and it dies.
The general rule is to plant a seed at a depth that equals twice its width.
Water newly-sown seeds with a mixture of one fifth of a teaspoon of Epsom salts in a litre of water to aid the germination process.
The magnesium in the salts will help stimulate the enzymes
that make the food in the endosperm more readily available to the young seedling.
Small seeds should be only lightly covered with soil, but larger seeds will be planted at a greater depth.
The surface of the soil dries out more quickly than it does a few millimetres deeper.
So small seeds that are surface-sown should be kept moist while the larger seeds should be given a good soaking at planting time
and then watered again only after they break through the ground.
If you water the larger seeds too much, they will rot in the moist soil.
The seed of many vegetables and flowering annuals are F1 hybrids, where the plant breeders have combined two different strains each
with desirable characteristics.
However, F1 hybrids usually do not set seed or the seeds are not viable.
To select tomato seed for planting, squeeze the pulp and the seeds on absorbent paper, e.g. a paper towel, and spread it evenly over
the paper.
Remove as much pulp as possible and lay the remainder in the sun for two weeks to dry the germination inhibiting enzymes.
Lay the paper towel with seeds uppermost on seed raising mix and lightly cover with fine seed mix.
Water lightly until the seedlings emerge.

5.16 Planting material
| See diagram 9.81: Bulb
| See diagram 9.82: Corm
| See diagram 9.83: Rhizome
| See diagram 9.93.1: Stem cuttings
| See diagram 9.93.2: Vegetative reproduction
Collect examples of the different kinds of planting material to show the students in the classroom.
Find pictures of planting material mentioned in the lesson from your agricultural reference library.
Show the students the different kinds of planting material and the pictures from the agricultural reference library.
Planting material means seeds or parts of plants that can grow to become a new plant.
The parts of plants may be pieces of stems or special kinds of stems.
Seeds are produced in the ovary of a flower after pollen from the stamen (father) fertilizes the ovary (mother).
So seeds are like the children of the stamen and the ovary.
The pollen that fertilizes the ovary may come from the same flower as the ovary (self-pollination)
or come from a different flower on a different plant (cross-pollination).
The seeds (children) will have a mixture of the different characters of the parent plants.
So the seeds will be like brothers and sisters.
When they grow, they will all look like the
parents and like each other but none will look the same.
Plants that grow from parts of plants will grow to look the same as the parent plant.

Parts of plants used for planting material:
1. Stems
9.54.0 Stems
Stem cuttings
When the nodes of some plant stems touch damp soil, they will produce roots.
If these stems are cut between the nodes then each node can form roots and shoot and grow into a new plant, e.g. sweet potato or
cassava.
Stems or stem tips are cut and planted so that some nodes are under the ground and some are above the ground.
The nodes under the ground produce roots and the nodes above the ground produce leaves.

2. Corms
9.1.2.0 Corm
Corms are swollen stem bases, e.g. taro and banana.
The corm will have small buds growing from the nodes.
The corm can be cut into "bits", which are pieces of corm with buds.
Each "bit" can be planted to grow into a new plant.

3.Stem tubes
9.1.6.0 Stem tuber, potato tuber
Stem tubers are swollen stems or branches that grows in the ground, e.g. yams.
Each "eye" in the tuber is really a very small leaf and axillary bud.
The tubers can be cut into pieces, each containing an eye, and planted.
Each piece will grow into a new plant.

4. Root tubers cannot be used for planting material because there are no nodes or axillary buds in roots.
However, at the neck of the tuber where the root becomes stem axillary buds can sprout, be separated, and then used as planting
material, e.g. sweet potato or cassava.

5. Bulbs
9.1.1.0 Bulb
Bulbs are shoots with fleshy leaves that store food, e.g. spring onion.
Some plants can produce little daughter bulbs that can be separated and planted to grow into big plants.

6. Shoots are from underground stems that produce shoots from their axillary buds.
They can be separated by cutting, then planted out, e.g. sword suckers of banana corms, tops and slips of pineapples.

7. Rhizomes
9.1.4.0 Rhizome
Rhizomes are shoots that grows horizontally underground.
It can be easily broken into pieces, with each piece containing axillary buds.
The axillary buds can form new roots and shoots, e.g. ginger or turmeric, and many grasses.

8. Aerial suckers are branches which grow in the air than touch the ground.
Where a node touches the ground, a new plant can grow, e.g. pineapple aerial suckers, taro suckers, yam bulbils.

5.28 Seed sterilization
1. Sterilization procedures may be enhanced by:
1.1 Placing the material in a 70% ethyl alcohol solution prior to treatment with another disinfectant solution.
The use of a two-step (two-source) sterilization procedure has proven beneficial with certain species.
1.2 Using a wetting agent, e.g. "Tween 20", added to the disinfectants to reduce surface tension and allow better surface contact.
1.3 Conducting the sterilization process under vacuum.
This results in the removal of air bubbles and provides a more efficient sterilization process.

2. Orchid seeds are very small and contain little food reserves.
A single seed capsule contain 1, 500 - 3, 000, 000 seeds.
Sowing the seed in vitro makes it possible to germinate immature seed (green pods).
It is much easier to sterilize green capsules about two-thirds ripe than individual seeds after the capsule has split open.
For example, the time to maturity of Cymbidium is 10 months.
For green capsule sterilization, soak the capsule in a 100% bleach solution for 30 minutes.
Dip the capsule into 95% alcohol, and flame.
Under aseptic conditions, open the capsule and scrape out the seed.
Carefully layer the seed over the surface of the culture medium.

3. Dry seed sterilization
Collect seed and place in either a small flask or bottle, or place in a shortened pipette which has one end sealed with cotton.
Seal the other end of the pipette with cotton, once the seed has been placed in the pipette.
Prepare a solution containing 5-10% commercial bleach containing a few drops of Tween 20.
Add the bleach solution to the flask, or draw up the solution into the pipette.
Swirl the flask containing the seed and bleach or repeatedly draw and aspirate the bleach solution in and out of the pipette.
Sterilize the seed for 5-10 minutes.
Remove the bleach solution and rinse the seed with sterile tissue culture grade water.
Transfer the seed to sterile culture medium.

9.8.0 Planting crops
See diagram: 4.0: Sterilizing the soil | See diagram 61: Sweet potato planting, planting material
See diagram 4.0: Seed beds and seed boxes
These lessons are designed to make the students think about the advantages of using a seed bed.
Sow some plants directly into a garden.
They are not raised in a seed bed and then transplanted, e.g. bean, peas, carrots, cucumbers, melons, and pumpkins.
Use a seed bed for plants like tomato, onions, lettuce, because you must have good seedlings if you want to make the best use of
small areas of gardens.
Planting material includes stem cuttings, rhizomes, tubers, corms, and seeds.
Only seeds can be imported from other countries.
They must be in sealed silver packets and have the scientific name of the plant written on the outside package.

9.8.1 Imported seed
Advantages
1.1 They are free from diseases and insect pests.
1.2 All the plants grown from the seed in a packet will be the same.
1.3 The seed has been chosen to give a high yield.
Calculate exactly how much seed is needed and buy the number of packets.
Disadvantages
1.4 Imported seed is expensive.
1.5 There are many different varieties and it is hard to know which to choose.
1.6 You cannot use hybrid seed to produce seed for another crop so you need new hybrid seed for each crop.
1.7 Imported seed may not be suitable for the tropical conditions.

9.8.2 Grow your own seed
Advantages
2.1 The cost of producing your own seed is less than imported seed.
2.2 Seeds from the best plants in your garden should be suitable for the conditions in your garden.
Disadvantages
2.3 The plants produced may vary a lot due to genetic variation.
2.4 The seed may carry disease or insect pests if not treated with pesticide.
2.5 The seed may die if it not stored in cool dry conditions.
2.6 There may not be enough seed for your needs.

9.8.3 The four methods of planting
9.8.3.1 Direct planting of seeds and cuttings into the field
The soil should be prepared and fertilized 2 weeks before planting.
Planting must be done at the correct depth and correct spacing.
The seeds must look fat and healthy.
Plant them in furrows or holes, singly or plant 2 seeds per hole and destroy the smaller seedling.
You may plant cuttings singly but there are many different methods.
Advantages
1.1 It is a cheap and simple method.
1.2 There is no damage due to transplanting.
1.3 Plants are easy to look after.
Surviving plants may be stronger.
1.4 Some seeds must be sown this way. e.g. bean
Disadvantages
1.5 Less seed germinates so there are fewer baby plants
1.6 You have less control over what is grown in the field.

9.8.3.2 Planting in a seed bed
Plant in a seed bed of fine even soil sheltered by a roof.
Later chose the best plants for transplanting. Use a seed bed of specially mixed soil sheltered by a leaf roof.
The soil is a mixture of 2 buckets of sieved good soil and 1 bucket of washed river sand and 1 bucket of rotten compost.
Sterilize the mixture to kill weed seeds, pests and diseases, by heating in a drum oven.
Seedlings may need thinning out and the plants should be hardened by not watering and by gradually removing the roof a few weeks
before transplanting.
Select the strongest plants for transplanting on a dull afternoon and water the transplants well.
Plant seeds and other planting material as follows:
2.a Long deep grooves in the raised bed or field (furrows).
Use a hoe to make the grooves.
2.b Short shallow grooves in the seed bed called drills.
Use a rake handle to make the grooves.
2.c Hills or mounds to allow all-round drainage for sweet potato, corn and pumpkin
Advantages of planting in a seed bed:
2.1 More seeds germinate and more baby plants live.
2.2 It saves time because other plants can be growing in the field while baby plants are in the seed beds.
2.3 You have more control over what is grown in the gardens.
Disadvantages of planting in a seed bed:
2.4 It is an expensive and complicated method.
2.5 It wastes time.
2.6 Transplanting may damage roots.
2.7 You must water the plants every day.
2.8. Skill is needed to look after baby plants properly!

9.8.3.3 Planting in seed boxes
1. Use boxes that are about 24 cm × 24 cm × 15 cm and are kept on shelves in greenhouses with a roof of sticks or leaves or
artificial shade, e.g. "Sarlon".
Sterilize the soil in the seed box before planting the seeds.
Plant them in regularly spaced holes.
You can mix very tiny seeds with dry sand before sowing to make them easier to handle.
The sand spaces the seeds well.
Another way is that you may sprinkle small seeds along a shallow drill and when the cotyledons have just opened,
you transplant the seedlings into a second box with regularly spaced holes in the soil, called "pricking out".
Sterilize the seed boxes and soil in them to kill pests and diseases.
You can take the seed boxes to the field when transplanting.
Make seed boxes with wood or tin plate, e.g. kerosene tins.
However, you must make sure that air can get into the soil and that the soil is well drained, otherwise the roots will not grow well.

2. To propagate plants from seeds, buy special seed raising mixtures or use the same potting mix for seeds as you do in the pots.
Fill the trays with potting mix, smooth off the top, and water with a fine nozzle.
Put a small indentation with your finger in each cell.
Sprinkle in seeds.
For fine seeds, put up to six in each cell.
For big seeds, put two in each cell.
Cover with perlite to give a light weight cover for the seeds to push through, and providing moisture retention.
The smaller the seed the thinner the cover, larger seeds should be covered by the same depth as they are in diameter.
Cover the seedling trays with plastic to provide high humidity and to avoid moisture loss.
Keep the seeding trays moist.
When the true leaves have emerged, you will need to fertilize.
When the seedlings are ready to pot up, or plant in the ground, place the trays in the sun for three to five days, to "harden" the top
growth and increase the strength of the root system.

9.8.3.4 Planting in a plant nursery
Use a plant nursery for the three following reasons:
1. Give seeds and young plants the best conditions for germination and rapid growth.
2. Use the land for other purposes while the plants are in the nursery.
3. Prepare the land for planting right up to the time of transplanting.

9.8.7 Transplanting
Teach the students to transplant seedlings correctly.
This lesson should teach students to transplant seedlings with death of the plant or setback.
This is a practice lesson so any extra seedlings can be used because you can pull them up later.
You can use lettuce, chilli, or even weed seedlings.

The three causes of "transplanting shock"
1. Root damage:
The roo t hairs are very delicate and are in contact with the soil particles.
Even if the soil is slightly shaken the root hairs can be broken and then it takes some time for the plant to grow new root hairs.

2. Stem damage:
If the plant cannot be picked up by digging the soil and lifting, the plant can be safely lifted up by a cotyledon or leaf.
If you damage this the plant it can soon grow a new leaf.
However, if you try to pick it up by the stem and you damage the stem then the plant cannot repair it and will die.

3. Loss of water:
If the plant is transplanted from shade to sunlight it will dry up easily because the leaves are used to being in the shade.
A week before transplanting, start removing the shade so that the plant is used to full sun before transplanting to prevent excess loss
of water.

Use 3-4 seedlings for each student, a place for transplanting the seedlings, and spoons or trowels.
Individual practice on why seedlings must be transplanted gently. let each student dig a transplanting hole and water it.
Then water the seedlings. Show the students how to dig up a seedling.
Then plant the seedlings in the transplanting hold deeper than it was in the seed bed.
Water again.

4. Let each student transplant one seedling.
Watch for any accidents.
Tell them to water their seedlings then put some shade over them.
5. Visit the seedlings each day for 2-3 days.
If they are they all growing well, remove the shade.
Do any plants have setbacks?

4.1 Site of a plant nursery
Choose the site of the nursery carefully.
It should have a constant water supply and not be flooded.
The land should be flat and sheltered from strong winds.
The soil should be well drained, with a pH between 6 and 7, cleared of tree roots and weeds and be deeply cultivated to produce a
plot to be shaded by trees or buildings anytime of the day.

4.2 Protection from wind for a plant nursery
Plants in the nursery must be protected from: strong winds, the hot sun in the middle of the day, and raindrop damage.
The best protection from strong winds is a brush fence 3 metres high but for the long term it is better to plant windbreaks using trees,
e.g. Leucaena.
In most places build walls and a door that you can lock to keep out animals.

4.3 Shade for a plant nursery
A shade roof 2 metres above the ground supported by posts 3 metres apart can protect plants from the hot sun and heavy rain.
The roofing material that is the easiest to collect and put on the roof are coconut palm leaves.
However, this material has the disadvantages that the shade is uneven and blocks out too much sun in patches.
Also light rain may run off the roof and not get to the plants at all.
The best roofing material is lots of sticks or bamboo about 5 cm in diameter that you can be arranged to provide an even shade and let
some light and rain pass through.
Having lots of small spaces in shade is best.
It is possible to import shade made of plastic called "Sarlon" but it is expensive and may not last many years in the hot tropical sun.
Two weeks before transplanting the plants should be hardened by gradually removing the shade so that you only transplant those plants
that can grow well in the hot sun.

4.4 Seed beds in a plant nursery
Plants can be grown in the seed bed or in seed boxes or other containers.
The advantage of using the seed bed is that it does not take much preparation or looking after.
The disadvantage is that you may damage the plant roots when transplanting.
The advantage of using seed boxes or containers is that you have more control over the plants and you can select the best plants for
transplanting.
The disadvantages are the costs of containers and benches, the plants must be looked after more.
You must water them every day and sometimes the plant roots do not grow properly in the containers.
Using seed boxes and containers in a plant nursery is always worthwhile provided you prepare the students to look after them.

4.5 Soil mixtures for a plant nursery
There are many ways to make up a soil mix.
One mix could be:
2 buckets of sieved black topsoil,
1 bucket of river sand,
1 bucket of old sawdust or crushed dried leaves,
1 drink can of NPK fertilizer 4% N, 6% P, 4% K + trace elements.
This should contain sulfur.
If the pH is less than 6, add lime.
The soil mixture used in the seed beds must be light and crumbly.
It should allow air to get in, hold water and let the extra water out easily.
If the soil mixture packs down in the seed box or container the plant roots will not grow well, provide the right amounts of plant
nutrients, be free from pests and diseases.

4.6 Sterilizing the soil for a plant nursery
Cook the soil mixture to kill disease and weeds.
You must cook the soil mixture over a fire for a couple of hours to kill off all the disease and weed seeds.
Cut the top out of an oil drum.
Make many small holes in it.
Make holes through the drum 30 cm above the bottom, and put iron bars through the drum.
Put the lid inside the drum so it rests on the iron bars.

4.7 How to sterilize the soil
See diagram 6.0.1: Sterilizing soil
1. Put water in the bottom of the drum.
2. Put soil in the top part of the drum.
3. Make the soil slightly wet.
4. Put a sweet potato in the soil near the top, put a cover on the drum.
5. Light a fire underneath the drum to boil the water and "cook" the soil.
6. After about 2 hours of cooking, check to see if the sweet potato is cooked.
If it is cooked, then the soil is ready.
You can use the seed box mixture again, but you must sterilize it each time before you use it.
If any of the plants in the seed box get a disease, then you must also sterilize the box before you use it again.
Put in boiling water for 15 minutes.

9.8.4 Pot plants
Planting in a container should be the ideal way to create optimum conditions for plant growth.
However, some plants have very specific requirements and some plants should never be grown in pots.
For example citrus grows well in pots but a tuberous begonia does not.
Before using pots, check which plants that grow well in pots in your area.
Overwatering is a common cause of pot plant death, especially kitchen herbs, so group pot plants together according to their watering
needs.
A drip irrigation system makes watering easier.
Pots made of terracotta or stone make take water away from plants so use a coat of sealant to make them less porous.
Maintain constant applications of fertilizer because the pot plant has little surrounding soil compared to the plant growing in the ground.
Some pot plants have very specific fertilizer needs.
"Seasol" and fish oils are useful soil conditioners for pot plants.

1. Dig a hole 4 × width and 2 × depth of the pot.
Loosen the soil at the sides of the planting hole.
Fill the hole with water and allow it to drain away.
Add wetting agent to half of the soil taken out and to be used as back fill.
Remove the plant from the pot by inverting the pot and tapping it until the plant with root ball emerges.
Place the plant in the hole with the top of the root ball level with the surrounding soil surface.
Fill the remaining hole with back fill.
Press the back fill down to leave a saucer-shaped depression around the plant.
Water the plant after planting and then water it once a week for two months with the volume of water equal to twice the volume of the
original pot.
Then water only when the soil feels dry.
Add some coarse mulch in a 50 cm radius but not touching the stem of the plant.
The applied mulch should contain composted animal manure and leaf litter.
Do not put fertilizers or new animal manure in the bottom of the planting hole because they may burn the plant roots.
Prune off broken branches from the new transplants.

2. Clay pots and plastic pots are tapered, i.e. they are wider at the top than at the bottom.
The taper makes it easy to get the plant and soil out without damaging the roots when you hit the upside down pot sharply.
However, clay pots are expensive, heavy and break easily if dropped or trodden on.

3. Use iron fish tins, drink tins and aluminium beverage cans for containers.
However, they are not tapered so cut the side of the tin with tin snips to get the plant and soil out.
Punch holes in the bottom and sides of these tins and drink-cans from the inside out.
These containers are so cheap and plentiful so it is a good idea to experiment with them.
Collect aluminium or tin plate beverage cans, half fill with soil mixture and use one for each seed.

4. Make basket pots by winding banana leaves around a log then taking the log away.
Also, you can cut bamboo to make pots but you may have to split them to get the plant and soil out.

5. Buy special pots made of compressed peat, e.g. "Jiffy Seven" pots.
They are excellent for transplanting single plants but they do not stand up for long before collapsing and they are expensive.
Stand them in a shallow tray to take up water then you can transplant without damaging the plants.

6. Use black plastic polythene bags called poly bags for plants that must be left in a nursery for a long time, e.g. coconuts.
Poly bags may get very hot if left in the sun and this can damage the roots.
They may come in the form of sleeves to provide extra drainage.

9.8.5 Interplanting
Interplanting is used when you grow different kinds of plants in different rows in the same garden.
One advantage of interplanting is that it allows you to grow more food without increasing the size of your garden.
You do this by growing small plants with short growing periods, e.g. radish, okra, lettuce, dwarf bean and spinach, between rows
of large plants with longer growing periods, e.g. tomato, cabbage, capsicum and eggplant.
Many food crops, e.g. peanut, corn, pineapples, banana and ginger, can be grown between coconuts and you can interplant
papayas or banana with pineapples.
The general rule in school food gardening is to grow your plants as close together as you can without the plants becoming stunted and
always to have a mixture of plants in your garden.
If you plant corn on ridges in the fields, also plant bean between the ridges.
Try some trials comparing single crops with interplanted crops, e.g. bed 1 sweet potato, bed 2 corn, bed 3. sweet potato interplanted
with corn.
Table 9.8.5 Examples of interplanting:
Row 1: maize, mung bean, lettuce, cucumber
Row 2: Chinese cabbage, tomato, tomato, maize
Row 3: radish, spring onion, lettuce, cucumber
Row 4: lettuce, tomato, tomato, maize
Row 5: radish, mung bean, lettuce, cucumber.

Advantages of interplanting:
4.1 You can grow more food in the garden
4.2 Some plants called "companion plants" can help others by protecting them against pests and disease.
4.3 Pests and disease cannot move between the same kinds of plants
4.4 Weeds are controlled by shading.
Find local examples of interplanting in village gardens.
Ask gardeners why they grow different kinds of plants together.

9.8.6 Companion planting
Another advantage of interplanting is that some plants have "plant friends", which can protect the plants from pests and help them to
grow better.
Marigolds planted in a border around a garden bed can protect plants of the tomato family from nematode worms.
Also marigolds can keep beetles away from beans.
Velvet bean can protect tomato from nematode worms.
Examples of plants and their friends
1. Bean, Friends: maize, cabbage, cucumber, lettuce
2. Eggplant (aubergine), Friend: bean
3. Pumpkin, Friends; maize, sweet potato
4. taro, Friend: spring onion
Use companion planting to control pests and diseases,
because it is difficult for pests and diseases to move between the same kinds of plants if they are separated by other kinds of plants.
Interplanting also helps control weeds by shading.

9.9.0 Seeds
Plant nurseries, fruit trees, seeds (Commercial websites)
See diagram 9.113.2d: Seeds planted at different levels
Description of type of plant
Common name and scientific name
Annual life cycle: 4 to 12 months, Biennial life cycle: up to 20 months
Hardy, survives frost / cool soil
Sow in soil at +10oC to + 20oC
Position: Full sun, part sun part shade, full shade
Months to flower, Months to harvest
Watering: Thirsty plant, seasonal watering, drought tolerant
Height and width of mature plant / flowers
Fungicide protection: Chemically treated / untreated
Sow: Direct / transplant
Best use by date
Germination %
Seed count in packet
Price
Packing reference number or lot number
Address of supplier

1. Choose seed from a group of plants that all have the characters you are looking for, e.g. large fruit or resistance to pests and disease.
There is then a good chance that the plants produced from this seed will have the same characters as the parent plants.

2. Other planting material, e.g. stem cuttings should be chosen from the best plants in the crop and must be free of pests and disease.
The best time to harvest seed is when the fruits are fully ripe but you may have to protect the fruit from birds and insects with paper
or plastic bags.

3. Seed should be dried in the shade and any juicy material picked off.
The seed must be clean of leaves, stalks and dust.
Put the dry seed in a jar, shake with copper oxychloride fungicide and then keep in a cool place.
Do not let students breathe in the fungicide dust or eat the seeds because all fungicides are poisonous.
Plant most tropical seeds soon after harvest.

4. When seeds remain alive and can germinate to form baby plants you say the seeds are viable.
Test the viability of seed before planting.
Otherwise, you waste time and effort on useless seed.
To test the viability of small seeds, soak 20 seeds for an hour then put the seeds on wet newspaper in a closed container.
After a few days, count the number of seeds that produce healthy roots.
Percentage germination = (No. germinated seeds / No. seeds planted) × 100.

5. With large seeds it is best to plant 20 seeds in a container in the nursery.
If fungus attacks the germinating seeds, shake the seed with copper oxychloride fungicides and do the test again.
Some seeds with very hard seed coats, e.g. Acacia, should be dropped in boiling water before sowing.
Most larger seeds germinate more quickly if soaked for 1-2 hours first.

6. The depth of sowing is usually printed on the packets of imported seed.
For your own seed the best rule is to sow the seed at a depth of at least 2 cm, or at a depth of 3 times the width of the seed (but not
more than 8 cm).
You can set up some interesting trials comparing the germination of seeds soaked and unsoaked, and at different depths in the soil.
If you sow seeds at too shallow a depth they may be uncovered by the wind, eaten by birds or rats, or the roots will not grow properly.
If you sow seeds too deeply, the plant may become exhausted and be unable to push the cotyledons above the soil.
Sometimes students will dig up sown seed of plants, e.g. peanut and eat them.
This is a problem of student discipline but it can be quite dangerous if the seeds have been treated with fungicide.
If you are direct planting, always dig the soil one month before planting seeds.
About 2 weeks before planting dig in rotted compost, wood ashes and fertilizer, which should have a high content of phosphate,
e.g. NPK 4%, 6%, 4%.
Phosphate makes roots grow well.

7. You can drop very small seeds into the furrow fairly close together then pull out the weaker plants to leave the stronger plants
growing at the approximate recommended spacing.
This method is called thinning out.
Also, you can plant a group of seeds in shallow holes at the correct distance and when the plants are 3 cm high destroy all plants
except the biggest ones.
The advantages of sowing seeds directly into the soil are that it saves time and does not damage the roots during transplanting.

9.9.2 Depth of Sowing.
The two dangers for a seed
1. The seed may dry out.
Then it may not germinate because it has no water.
You can stop this danger by covering the soil very lightly with some powdered animal manure or leaf mould.
It also helps if you mix some sand with the topsoil because this sand will keep the soil open and let rain in.
2. The other danger is that seed may get too wet and be attacked by a fungus called the "damping off" fungus.
You can stop this fungus by putting sand in the topsoil.
This sand will let a lot of rain drain away quickly.

9.10.0 Vegetative reproduction
See diagram 9.93.2: Vegetative reproduction
Make more plants by taking pieces of a plant and using the students to grow new whole plants.
This is called vegetative reproduction.
The advantages of using vegetative reproduction is that the piece of the plant usually grows easily, and the new adult plants produced
will all have exactly the same characters as the parent plant.

9.10.1 Cuttings
See diagram 9.93.1: Cuttings
1. Cuttings may be a piece of root, stem, leaf or a bud that can grow to form a new plant, e.g. stem cuttings of sweet potato, cassava,
yam, banana, ginger, turmeric, pineapple, and taro.
Select planting material suitable for cuttings that are the correct size and free from disease.
Plant out the cuttings at the recommended correct distances.
We can make more plants by taking pieces of a plant and using them to grow new whole plants.
This is called vegetative reproduction.
The advantages of using vegetative reproduction is that the piece of the plant usually grows easily, and the new adult parents
produced will all have exactly the same characters as the parent plant.
There are three methods: cuttings, divisions, grafting.
A cutting may be a piece of root, stem, leaf or bud.
A root cutting must be able to produce a shoot and a stem cutting must be able to produce roots, usually from a node.
Cuttings must get enough water and air so that you can produce roots and shoots.
Division is a natural process when a plant forms new plants as offshoots.
These are parts of the plant grow to form new plants and later separate from the mother, e.g. spring onion, Chinese taro.
Grafting is difficult to do and usually can be done only by people who have studied horticulture in an agricultural college.
Grafting means to make part of one plant grow on another whole plant.
This is done when other forms of vegetative reproduction do not work and when we want to combine the characteristics of two plants
with different characters.
For example, if one kind of plant produces good fruit, but its roots are easily attacked by pests and disease, and if a second plant
produces small fruit but its roots are not attacked by pests and disease, then if we could graft branches of the first kind of plant onto the
stem of a second kind of plant, so we would have a tree which produces goo fruit and which has roots nit attacked by pests and
disease, e.g. citrus.
The piece of plant or branch which is grafted is called the scion and the tree on which it is grafted is called the stock or rootstock.
For grafting you need a sharp knife, a saw for large trees and tying material, e.g. string, nails and special glue.
You will need plant stems suitable for cuttings, e.g. Hibiscus.
The plant stems for cuttings should be about one cm thick.
Count the nodes.
The leaves grow out of the nodes.
Cut the branch to make a cutting with four nodes.
Cut at an angle.
Push the cutting into the ground with two nodes underground.

2. A cutting may be a piece of root, stem, leaf or bud.
A root cutting must be able to produce a shoot and a stem cutting must be able to produce roots, usually from a node.
Cuttings must get enough water and air so that they can produce roots and shoots.
New roots and shoots can come from buds at the nodes.
If a cutting is half buried in sand, roots will grow from the lower part and shoots from the part above ground.
Do not mix compost or leaf mould with soil used for cuttings but use clean sand.
After the cuttings have rooted, they can be moved to a richer soil with leaf mould in it.

3. To propagate plants from cuttings, fill trays with potting mix, smooth off top, and water.
Collect cutting material from healthy plants.
Use sharp clean secateurs and cut below a node.
For small-leaved plants remove lower leaves from cutting.
Larger-leaved plants may also require some remaining leaf area to be reduced.
Make a hole in potting mix (use a stick not much bigger than the cutting) and place in prepared cuttings.
Gently press around cutting.
When all cuttings have been done, water in well.
This will ensure that cuttings are in contact with potting mix.
Trays of cuttings are then placed in an igloo or other humid environment.
Keep moist.
Once cuttings have roots you will need to fertilize them.
The best cuttings medium is 1 : 4 peat : perlite.

4. Compounds to improve the success rate with rooting cuttings include auxin hormones which induce root formation.
Fungicides used along with the rooting powder may have a stimulatory effect or a depressing effect on root production.
An experimental problem is how to score "rooting" in numerical values to allowing calculation of a mean of all cuttings for one treatment?
In Australia rooting hormone compounds are available as a dry powder, gel or liquid, e.g. "Ezi Root Gel", a blend of
(indole-3-butyric acid) (IBA) and (naphthylacetic acid) (NAA), hormones, with a wetter and fungicide.

9.10.2 Division
| See diagram 9.81: Bulb
| See diagram 9.82: Corm
| See diagram 9.83: Rhizome
1. Pull apart the diffuse plants with many shoots or offsets.
Adult cells of plant organs may revert to meristematic activity and reveal their original embryonic characters.
Division is a natural process when a plant forms new plants as offshoots, e.g. bulbs, corms, rhizomes.
Parts of the plant grow to form new plants and later separate from the mother, e.g. Michaelmas daisy, delphinium, suckers of
raspberry canes.
Division can also refer to the separation of side shoots from a bulb as in spring onion or separating the suckers that grow up from the
banana corm or breaking a ginger rhizome into pieces.

2. To propagate plants by division, turn pot upside down squeeze and shake plant out.
Remove as much potting mix as possible.
Pull plant apart into sections, depending on whether you want to produce a few well established plants or many smaller plants.
Use a knife or secateurs to divide plants with large roots or rhizomes.
Matted pot bound roots can be cut.
Trim long roots to a depth of half a pot.
Half fill pots with potting mix.
Hold newly divided plant in the pot and fill with potting mix.
Water in well, then water in with a liquid seaweed-based fertilizer, to prevent transplant shock.

9.10.3 Stooling
See diagram 51.13.0: Banana stool
The plant is cut down to ground level where it forms lots of new shoots.
Each shoot then produces its own roots.
These rooted shoots can be cut off and planted separately.
Stooling can be used on guava and bananas.

9.10.4 Layering
See diagram 9.93.2: Layering
Layering is used for carnation, rubber plant, lilac, rhododendron, rose, clematis, blackberry
The plant is bent the down until a branch touches the ground, then the branches are secured it with pegs or wire ground hoops.
New shoots and roots then form from each node touching the ground, then, by cutting between each node, new plants are formed.
Layering can be used on mango.
Bend a branch down over the soil and fix pegs so that some nodes are below the surface.
Adventitious roots grow from the buried nodes.
The axillary bud near the peg grows upwards into an aerial shoot.
Cut the layered stem from the parent plant and let it grow independently.
For air layering of the rubber plant, make a longitudinal cut below a node almost to the centre of the stem.
Treat the cut with plant cutting powder then bind on moist cotton wool covered with polythene film.
Roots form in the layering.
Experiment
You will need to find a plant whose branches you can bend down for layering.
Bend the branches down and use a peg or piece of wire to keep the branch bent under the ground.
After about a week examine the branch by gently washing away the soil.
New shoots and new roots come from the nodes.
When the new shoot is growing strongly above the ground you can cut the old branch and then you have a new plant.

9.10.5 Marcotting, air layering
See diagram 9.93.3: Marcotting
1. Remove a strip of bark 1-2 cm wide, then scrape it to remove any remaining bark or cambium tissue.
2. Cover girdle with moist sphagnum moss.
3. Wrap with polyethylene film.
Wrap and tie ends with polyethylene tape or electrician's tape.
In marcotting (marcottage), a cut is made below a joint or node and covered with a moss into which new roots grow.

1. Propagation by air layering or marcottage, by Paul Moore, Indoor Citrus and Rare Fruit Society
Air layering is a method of propagating several kinds of evergreen, broad-leaved, tropical and subtropical fruit trees.
The Chinese have used this technique, which they call "gootee", extensively for more than 1, 000 years to propagate the lychee,
a species difficult to propagate by other asexual methods.
Air layering, also known as "marcottage", is the preferred method of propagating guava, lychee, longan and the ornamental
Ficus elastica.
Other fruits and nuts that can be propagated as marcots are acerola (Barbados cherry), carob, carambola, cashew, citron
(Citrus medica), fig, lime, lemon, pomelo, loquat, macadamia and mango.
Other methods, e.g. budding, grafting, and cuttings are generally preferred over marcottage, because they are easier, less
time-consuming and more economical of propagating material.
Also, these alternate methods can be more successful in non-humid regions.
Air layering is more reliable in outdoor climates that remain humid and rainy during the rooting period, and in greenhouse environments.
The most limiting factor in marcottage is keeping the rooting medium continuously moist.
Periodic rewetting will be required if it dries.
The air layer is started by selecting mature branch tips that developed in the previous growing season.
Spring is the best time of year.
The selected terminals are girdled by removing a ring of bark 1 to 2 cm wide and about 12 to 15 cm below the tip.
Scrape the remaining inner bark tissue thoroughly, removing it down to the wood.
The purpose of this step is to prevent the girdle from healing and to induce rooting above the cut.
Treating the exposed cut and the bark above the girdle with a rooting hormone preparation, e.g. indolebutyric acid (IBA), 8000 ppm
or 16000 ppm.
Place a large double handful of moist, but not wet, sphagnum moss about the girdled surfaces and the intact bark above the cut, and
then wrap with polyethylene film.
Tie the upper and lower ends tightly around the stem.
Rewetting the sphagnum may be necessary if it dries during the rooting process.
Leave the marcot on the mother tree until the roots are visible through the plastic film.
This may take from two to six months.
After adequate rooting occurs, sever the marcot, unwrap and transplant it into a container.
Survival is improved if the air layer is kept in a humid greenhouse or a cool, shaded site until well established.
Since there is an imbalance between root and top, is also recommended to prune back the top when it is potted.
Normally marcots are not planted into the open ground until the spring following potting, or until they are well rooted and established
in their containers.

2. Marcotting means wrapping bags of damp soil or other material around a stem so that roots will grow out of it.
Later the stem can be cut into lengths with roots growing out of the lower end.
It is a way of multiplying some plants that are hard to strike (start to grow) as cuttings.
Cut out a complete ring of bark from a stem, and then use a cloth to bind damp earth, sawdust, or plant material around the cut stem.
Sometimes it helps to paint the cut with a substance that causes growth, e.g. indole acetic acid (IAA), but this is not essential.
Roots will grow from the cuts and so new plants can be formed by cutting between the cut rings.
This can be used on woody plants, e.g. mango, avocado and cashew.
Choose some plant, e.g. hibiscus, cordyline or fig.
Ring bark it at several places up the stem.
Use a sharp knife and cut a shallow "V" right around it.
Get some husk fibre from a coconut and soak it in water.
Cut it into pieces.
Wrap a handful of wet fibre around each cut made in the stem and hold it in place with a piece of rag and string.
If possible wrap a piece of silver paper around the bundle. This reflects the sun and stops it getting too hot.
This can be used on woody plants, e.g. mango, avocado and cashew.

3. Marcotting or air layering means to cut out a complete ring of bark from a stem, and then use a cloth to bind damp
earth, sawdust or plant material around the cut stem.
Sometimes it helps to paint the cut with a substance which causes growth, e.g. indole acetic acid (IAA), but this is not essential.
Roots will grow from the cuts and so new plants can be formed by cutting between the cut rings.
This can be used on woody plants, e.g. mango, avocado, and cashew.

4. Stem rooting of Chinese Hibiscus uses a plastic litre soda drink bottle with its bottom cut out and slit along one side, so it could be
slipped around the Hibiscus stem, tied in place upside down and filled with potting soil.
Certain plant stems sprout roots if their stems make contact with moist soil.
The stem will fill the potting soil with roots, then the stem can be cut right below the bottle's mouth, the bottle will be removed,
and when the root-filled soil is planted there'll stand a new Chinese Hibiscus already one metre tall.

9.10.6 Grafting
See diagram 9.93.2: Budding and grafting
1. This means to make part of one plant, the scion, grow on another whole plant, the stock or rootstock.
This is done when other forms of vegetative reproduction do not work and when you want to combine the characters of two plants
with different characters.
For example, if one kind of plant produces good fruit but its roots are easily attacked by pests and disease, and if a second plant
produces small fruit but its roots arc not attacked by pests and disease, then if you could graft branches of the first kind of plant onto
the stem of the second kind of plant, you would have a tree that produces good fruit and that has roots not attacked by pests
and disease.
For grafting you need a sharp knife, a saw for large trees and tying material, e.g. string, tape.

2. Grafting is difficult to do and usually can be done only by people who have studied horticulture in an agriculture college.
Grafting means to make part of one plant grow on another whole plant.
This is done when other forms of vegetative reproduction do not work and when you want to combine the characters of two plants
with different characters.

3. Always buy grafted fruit trees because:
3.1 the fruit quality of the mother tree may not be retained in the fruits of the seedling tree,
3.2 the seedling tree takes longer to reach the fruit-bearing stage,
3.3 the seedling tree grows taller and so is more difficult to manage and to harvest fruit from it.

9.12.0 Crop care
Think about the different jobs to do in the garden to look after the crops.
Write 2 column headings on the chalkboard:
Garden jobs and Reasons.
Remember a different job or a reason for doing the job and write all these on the chalkboard.
Other jobs that were done to look after the crops e.g. hoeing, staking, mending gates and fences, scaring birds, catching pigs, digging
or clearing drains, hand pollinating flowers, burning fire breaks.
Whenever these jobs are done make a note in your School Food Gardens Diary of the date, type of job done, where it was done,
time taken and number of students.

9.12.1 Weeding, weed control
1. Weeds are plants that lower the yield of garden plants. A weed is a plant in the wrong place.
2. Weeds harm crops by 2.1 taking in water from the soil, then the garden plants do not have enough water,
2.2 taking plant nutrients from the soil, then the garden plants do not have enough nutrients,
2.3 shading the young crop plants then the garden plants do not have enough sunlight for photosynthesis,
2.4 having pests and diseases on them, which can later infect the garden plants, mixing with the crop, and
2.5 making it hard to harvest, e.g. sensitive plant growing among sweet potato.
3. The three types of weeds:
3.1 Very strong plants that are no use to us, e.g. lantana, common guava,
3.2. Plants that are weeds only when they grow in crops.
However, they may also be used by themselves, e.g. purslane is a common garden weed but it can be eaten as a green vegetable.
3.3 Plants from old crops are weeds because they may have pests and diseases on them, e.g. old maize (corn) plants left over from
a previous crop may carry disease.
4. Weeds can be controlled by:
4.1 Pulling out by hand, ring weeding around trees in tree crops,
4.2 Hoeing,
4.3. Cutting down with a bush knife,
4.4. Shading by leaves of plants, plant crops close enough so that their leaves will shade the ground,
e.g. sweet potato (kumara) or cover crops, e.g. Pueraria,
4.5. Spraying with chemicals called herbicides or weedicides.
Herbicides are dangerous, expensive and hard to use properly.
See 16.7.0 Herbicides, weedicides.

9.12.2 Thinning
Some plants with tiny seeds cannot be transplanted.
They can be sown along a shallow drill and later some seedlings can be pulled out leaving seedlings 5 cm apart.
This is called thinning.
Pull out diseased or weaker plants.

9.12.3 Fertilizing, top dressing and side dressing
Top dressing and side dressing refers to adding fertilizer or manure to a growing crop, e.g. nitrogen fertilizer for leaf crops, tomato,
and hibiscus cabbage.
Dig a shallow ditch with the hand or hoc around each plant, put the fertilizer in, and cover it with soil.

9.12.4 Hoeing
Hoeing is used to control young weeds and let air into the soil.
Hoeing up or hilling-up means to use the hoe to pull up soil around the plant stems and cover the roots well.
It is used for plants, e.g. maize, which have shallow roots and for sweet potato to cover exposed tubers and protect from weevils.
The hoe should never be used so deeply as to damage the plant roots.

9.12.5 Watering and drainage
Teach students how to water plants and check the drainage.
1. Plants need water for life and growth.
If there is not enough water in the soil plants will wilt then die.
If there is too much water in the soil there is not enough air for the plant roots to breathe and then the plant will die.
In good soil, a loam, the water will drain down leaving enough water and air in the soil for the plant.
The soil around plant roots should always be damp but not wet.
Test this with your finger.
If the soil is dry the leaves will wilt and the plant will later die.
2. Sandy soils drain too quickly.
In dry weather sandy soil in raised beds must be watered every day.
Sandy soils should be watered more often than clay soils.
Clay soils drain too slowly.
Clay soils need watering only once each week.
3. Plants should be watered in the late afternoon with a fine spray so as not to wash away the soil.
Water during the afternoon or evenings and keep the leaves dry.
However, some gardeners in tropical regions do their watering only in the early mornings to keep plant foliage dry and be less easily
infected by viruses and bacteria.
4. If you water every day the plant will only grow shallow roots.
Soak the soil thoroughly every few days to make the plant grow deep roots.
Deep-rooted plants like tomato, pumpkins and sweet potatoes should be watered every 2 weeks.
5. Do not wet the plants because this helps plant disease, water the ground only.
If you cover soil with mulch made of chopped grass and leaves the soil will not lose much water.
6. Before starting a garden you should test the drainage.
After rain or a heavy watering dig holes 50 cm deep.
If water remains in the holes for a day make their garden somewhere else or dig drains.
7. The best drains are trenches 50 cm deep filled with large rough stones to a depth of 20 cm then covered with small stones then
topsoil.
Raised beds, ridges and hills or mounds provide drainage.
8. Show the students how to water properly. [Keep the leaves dry and soak soil every few days using a fine sprinkler.]
9. After heavy watering, dig holes 50 cm deep to see if the soil is well-drained.
10. Construct a drain in the garden to carry away excess water.

9.12.6 Staking
Staking means giving support, using sticks or wires, to vegetables, e.g. tomato, winged bean, eggplant and choko.
Climbing plants save space in the kitchen garden.

9.12.7 Plant protection
Plant protection refers to controlling pests and disease by:
1. picking out by hand diseased plants or insect pests,
2. spraying with pesticides or fungicides,
3. burning diseased plants or parts of plants,
4. pulling out all plants left over from the previous crop and other weeds.
This is called garden hygiene.

9.12.8 Harvesting
Harvesting must be done regularly and just before the crop is needed in the kitchen.
Sweet potato can be stored for a few weeks if it is:
1. not damaged when dug up,
2. kept in a moist atmosphere for a few days to toughen the skin,
3. stored in a cool place.
After harvest work, clear out all the crop plants and weeds left behind and put them on the compost heap.
Then dig in rotten compost or manure for the next crop.
You may plant a legume cover crop if the garden will not be planted for some time e.g. sunn hemp, butterfly pea, kudzu, cowpea.
This will protect the soil from erosion, control weeds, and put some nitrogen plant nutrient in the soil.

9.13.0 Mulching
1.0 The word "mulch" comes from "mulsh" meaning "soft".
Garden mulch is a cover of dead plants, a 10-15 cm thick layer of leaves, chopped grass, husks, weeds and other plants that act as a
blanket layer over garden soil.
The best mulch has particles larger than 5 mm to allow any rain to filter through.
Finer particles capture and hold rain water and may prevent the water reaching the soil and plant roots.
During dry periods fine textured mulch absorbs water that may later be lost by evaporation and not passed on to the plants, so use
broad textured mulch that allows water to percolate down to the plants.
The finer the mulch, the shallower the mulch layer.
All garden soil should be completely covered with mulch, leaving no bare patches on the soil.
Note any weeds on the bare soil and under the mulch.
Feel the temperature of the bare soil and the soil under the mulch.
Mulch should not touch the stems of plants because it may contain pests and diseases, e.g. collar rot.
Black plastic is sometimes used as mulch when vegetation is not available.
In the spring, add mulch and use an organic soil conditioner to improve the water holding capacity of the soil.
Apply a wetting agent after mulching to prevent waste of water.
Mulch is not mixed into the soil but it enters the soil as it rots down rots slowly into the soil to improve the soil structure.
As the mulch slowly rots into the soil, new plant material should be added on top of the mulch.

2.0 Advantages of mulching garden beds:
2.1 controls of weeds by shading them from sunlight,
2.2 stops rainfall from washing away the soil,
2.3 conserves water that the plant can use in the dry season,
2.4 lessens evaporation from the soil,
2.5 improves the soil structure, as mulch rots slowly into the soil,
2.5 acts as a slow release fertilizer as it adds nutrients to the soil,
2.6 provides a home for plant friendly insects.
2.6 insulates soil from sunlight and the radiant heat from the sun,
2.7 protects the soil from compacting and the splash erosion from heavy rain drops,
2.8 stops rainfall from washing away the soil,
2.9 stabilizes soil pH,
2.10 increases beneficial soil organisms.

3. Disadvantages of mulching garden beds
3.1 Insect pests and disease may live in infected plants used for mulch, so always ask a field officer from the Department of Agriculture
whether it is safe to use mulch with food crops.
3.2 More work is needed to collect, cut and put plant material on the soil.
3.3 The work is often not done properly leaving bare patches.
3.4 Dry grass mulch or dry compost that is not rotten may take nitrogen plant nutrients out of the soil, called "nitrogen draw down".

5.38 Mulch protects soil
See diagram 51.9: Mulch for planting bananas | See diagram 52.11: Mulch for planting coconuts
Teach the students to mulch garden soil.
1. Use a sloping garden bed.
Cover half with mulch and leave the other half not covered.
After about one month note the following differences:
2. Feel the bare soil and the soil under the mulch.
What differences do you see and feel?
3. All your garden beds should be mulched, completely covered to a depth of five cm.
This mulch will gradually rot down into the soil so each month new mulch should be added.
The best mulch is chopped grass, however some people should banana leaves and even black plastic.
Because of the danger from pests and diseases living in the mulch do not let the mulch touch the stems of the plants.

9.88.1 Plant growth regulators
(Phosphonates C-PO(OH)2, or C-PO(OR)2, where R=alkyl)
Ethephon phosphonate, 2-chloroethyl-dioxido-oxophosphorane, ClCH2CH2P(O)(OH)2, decomposes to ethylene and dihydrogen
phosphate, plant growth regulator, used for cotton, pineapple, wheat, coffee, kiwi fruit, tomato grape, apple, sugar cane, apparently
not a danger to the environment.
Glyphosate, herbicide: 16.7.3.

9.89 Commercial rooting powders for stem cuttings
1. Use commercial plant cutting powder (rooting powder, plant striking hormones), e.g. "Root Strike", to stimulate and produce
healthy roots on cuttings.
The active constituents of the powder are indole acetic acid (IAA), the main auxin of most plants, or indolebutyric acid (IBA), or
naphthalene acetic acid (NAA).
Store the plant striking hormone in a dark cool place and do not let it contaminate streams, ponds or soil.

2. Select healthy end growth 10 mm or less in diameter after the growth period of the plant.
Cut at an angle or select a "heel", where a branch joins.
Cuttings leave two terminal leaves.
Moisten the cut end of the cutting, dip it into the cutting powder and plant into free draining soil.
Water the cuttings daily.
If you plant next to the side of a glass jar, you can observe roots forming near the cut surface.

3. A cutting should be 50 mm to 150 mm long with an end growth diameter of 100 mm or less.
Take three cuttings from the parent plant after the growth period, i.e. late summer or early autumn.
For shrubs that flower in winter, e.g. camellias or daphnes take cuttings in midwinter.
For shrubs that flower in the spring, e.g. azaleas, take cuttings in autumn.
For roses, take cuttings from new growth in late autumn, early winter.
Make an angled cut to take a healthy cutting from a parent branch.
Remove the bottom leaves but leave three small leaves at the top of the cutting.
Take cuttings in early morning or late afternoon.
Immediately put in water after cutting and as soon as possible apply plant striking hormone by pushing the cutting into the bag of
powdered hormone.
The potting mix used for the initial root stage should be free flowing and light weight.
However, free draining sandy loam can also be used.

9.90 Leaf cuttings, African violet, begonia, episcia, haya blanca, peperomia
1. For begonia, African violet, cape primrose, make cuts in the raised veins in the underside of the leaf at 5 cm intervals.
Press the leaf cut side down into moist potting mix and cover the edges of the leaf with potting mix to keep it flat.
Some people push the cut veins down into the potting mix with staples or pieces of semi-circular wire.

2. For African violets, remove the leaf with petiole and insert the petiole into moist potting mix in indirect sunlight.
New plants will form on the petiole in about 8 weeks.

3. For plants with succulent leaf blades, e.g. cathedral bells, mother-in-law's tongue, stonecrop, cut long leaves into 7 cm sections, dip
into hormone rooting gel, then insert the sections into moist potting mix.
For smaller leaves, just push them upright into the potting mix.
Keep the potting mix moist in bright shade.

9.91 Root cuttings, phlox, hollyhocks, wild cherry
Cut horizontally at the top of the root and cut at an angle at the base of the root for easy insertion into the ground.
Also, cut off the top of the plant just above the ground to form new shoots.

9.92 Stem cuttings, top cuttings, geranium, poppy, fuchsia, chrysanthemum, blackcurrant
See diagram 9.93.1: Stem cuttings | See diagram 9.93.2: Cuttings
1. Put one end of a cut stem in damp sand.
Note the wound tissue, callus, that develops from which roots form.
At the other end, dormant lateral buds form new shoots.

2. Cut two pieces of stem with leaves, from a geranium plant.
The most suitable are short, compact shoots on which the leaves are close together.
A cut is made just underneath a stalk bud.
Fill two flowerpots with sandy soil to just below the rim.
Plant a cutting half a finger length deep in each pot.
Press the soil firmly down around the stem and add water so that it packs closely around the cutting.
Put an inverted beaker over each cutting.
Label each flowerpot and put in the light but not direct sunlight.
Water the cuttings regularly.
The cuttings develop into new independent geranium plants.

3. Cuttings can form adventitious roots.
You can propagate poppies, geraniums, fuchsias, chrysanthemums and black and red currants by cuttings.
Fill two flowerpots with sandy potting compost.
Take two cuttings with leaves on attached from a geranium.
Make the cut close to and just under a bud.
Sturdy shoots with leaves close together are the most suitable.
Remove the bottom leaves from each cutting.
Plant each cutting 3 cm deep in a flowerpot and water well so that the soil is packed tight around the cuttings.
Put a beaker over each cutting but making sure you allow air to get in and out.
Keep the soil moist and do not expose the cuttings to direct sunlight.
After some time the shoots begin to grow.
At the point where the cut was made adventitious buds have formed and have put out roots.
This is the way a cutting develops into an independent plant.

9.93 Bud grafting, orange, rose, fruit trees, apple, pear, plum
See diagram 9.93: Bud graft, shield graft, saddle graft
Grafting is used to propagate plants where the tissues of one plant are physically fused with the tissues of another plant.
It is used widely in commercial horticulture for propagating gymnosperm and dicotyledon trees and shrubs.
Monocotyledons do not have enough vascular cambium, the thin layer between bark and wood, necessary for grafting.
One plant, the stock or rootstock, is chosen for the qualities of its roots.
The other plant, the scion, is chosen for the qualities of its stems, leaves, flowers or fruits.
For successful grafting, the vascular cambium of the stock and scion must be aligned so they can grow together.
The scion and stock will become fused to form a single plant.
A shoot from such a graft shows the character of the scion, not of the stock that nourishes the scion.
Successful grafts are usually between closely related plants.

1. Remove a bud from a plant with a small strip of bark and cambium, then insert it into a T-shape slit in the stock.
Tightly bind and wax the parts.
If the two areas of cambium are in contact, they produce a callus that unites scion and stock.
To obtain good quality fruit select only the best buds for the graft.

2. Bud grafting allows the following:
2.1. rapid multiplication of desirable plants from a single individual,
2.2. preservation of a type that does not come true from seed, navel orange and hybrids,
2.3. modification of the scion, apples and pears are grafted to dwarfing stocks to grow a smaller tree for convenience of size,
2.4. improved yield, grape varieties may yield better when not grown on their own roots,
2.5. extended climatic ranges using extreme climate tolerant root stocks,
2.6. disease resistance by grafting susceptible scions to resistant stocks.

9.94 Whip and tongue grafting, citrus fruit and ornamental trees
See diagram 9.96: Whip and tongue grafting
The scion and stock will become fused to form a single plant.
A shoot from such a graft shows the character of the scion, not of the stock that nourishes the scion.
Successful grafts are usually between closely related plants.
Citrus trees can be grafted on rootstocks of hardy orange, Poncirus trifoliata.
Insert a cut twig, the scion, into an incision on the stem or root of another plant, the stock.
Bind the two tightly together to give firm contact between the cut surfaces.
Cover the join with an antiseptic wax to prevent infection.
The cambium tissue of the cut surfaces of the scion and stock form a mass of callus, soft, thin walled parenchyma, that joins the two.

Experiment
1. Cut the stock within 10 cm of the ground level.
Make a long slanting upward cut on the stock about 4 cm long.
2. Make a small downward cut on the stock to form a tongue near the top of the slanting cut.
Make a similar slanting downward cut on the scion, leaving a bud midway on the opposite side of the cut.
Make a tongue on the scion to correspond with the tongue on the stock.
3. Fit the tongue of the scion neatly into the tongue of the stock to hold the graft firmly in position.
The cut surfaces must be flush.
4. Bind the graft with moistened string and apply some warm grafting wax or bituminous tree dressing, e.g. "Arberex", to make the
joint airtight and watertight.
In all grafting the vital area is the "cambium layer", the thin green layer that lies between bark and wood.
See it in any young stem that is cut through diagonally.
The cambium cells retain the power of growing and knitting with similar cells.
When grafting, the cambium of the scion must be in direct contact with the cambium of the stock so the nearer the two cut surfaces
can coincide in length and width the better.
Other methods of grafting include the following: clematis (root grafting) rhododendron (saddle grafting) birch (inarching, one tree to
another).

9.97 Roots from plant parts
See diagram 9.85: Potato
Obtain a box of sand and put it out of direct sunlight.
Wet the sand thoroughly and keep it moist.
Plant any of the following in the sand:
1. various bulbs,
2. cuttings of begonia and geranium stems,
3. a section of sugar cane stem with a joint buried in the sand,
4. a section of bamboo stem with a, joint buried in the sand,
5. carrot, radish and beet tops, each with a small piece of root attached,
6. an onion,
7. an iris stem,
8. pieces of potato containing "eyes",
9. a branch of willow.

9.98 Potting mix
Be careful using potting mix.
Wear a mask so you do not hale any dust and do not shake the bag.
Wash the hands and clothes after using the potting mix then store it in a cool place.
Soil is not suitable for potted plants because it can get compacted too quickly.
A good potting mix will keep a balance between holding water and letting the water out so there is enough water for the roots
without then becoming waterlogged.
To stop too much soil being lost through the hole in the bottom of the pot, do not use a stone but use a piece of cotton cloth.
Some people include 20% coarse 60/40 coir (coconut fibre) in potting mix to "open" its structure.

Prepare two control mixes:
1. Minimal nutrient mixture of coconut fibre (50%), pearlite (25%), and vermiculite (25%).
2. Good nutrition but poor texture mixture of volcanic rock dust (50%), and cow manure (50%).
Test plants from a legume crop, a leafy crop, a fruit crop, and a root crop.
For hothouse tests, use seedlings of basil, lettuce and tomato planted in 8 cm diameter peat pots.
For a full sunlight test use seeds of bean, radish, rocket, spinach and tomato sown in 5 x 10 cm plastic pots.
Test home-made and commercial mixes by comparing growth of plants in them with growth in the controls.
An example of a successful commercial mix may contain animal manure, hoof and horn meal, trace elements, potassium phosphate
and other constituents.

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, sites 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 the hands.
Do not breathe in the spray.
Wash the 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 on a windy day, spray down wind.
Make sure the spray does not blow on other people.