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AGRODOK NO. 19

PROPAGATING AND PLANTING TREES

By:Harrie SchreppersPeter PaapErik Schinkel

Illustrations:Loes RoosBarbera Oranje

First edition 1998

English translation by:Sara van Otterloo Butler

ISBN 90-72746-78-3NUGI 835


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CONTENTS

1 INTRODUCTION ..........................................................................6

2 CHOOSING THE RIGHT TREE TYPE AND PLANTINGLOCATION.................................................................................... 8

2.1 Functions of trees .................................................................... 82.2 Choice of tree type................................................................... 92.3 Choice of location for tree planting......................................... 102.4 Limiting factors for tree cultivation ......................................... 12

3 PROPAGATION METHODS ....................................................... 133.1 Natural regeneration .............................................................. 133.2 Artificial propatation ............................................................... 133.3 Conditions for propagation methods ......................................173.4 Practical examples ................................................................ 19

4 COLLECTION AND TREATMENT OF CUTTINGS, WILDINGSAND SEEDS ............................................................................... 21

4.1 Mother trees .......................................................................... 214.2 Cuttings ................................................................................. 224.3 Root cuttings ..........................................................................274.4 Wildings ................................................................................. 284.5 Seed ...................................................................................... 29

5 DESIGN AND CONSTRUCTION OF A FARM NURSERY ......... 335.1 Location of a nursery ............................................................. 335.2 Design of a nursery................................................................ 34

5.3 Construction of a nursery ....................................................... 37

6 ACTIVITIES IN THE FARM NURSERY ......................................426.1 Planning................................................................................. 426.2 Preparation of seedbeds........................................................ 446.3 Pots ....................................................................................... 446.4 Sowing in beds ......................................................................476.5 Sowing in pots .......................................................................486.6 Planting in cutting beds.......................................................... 49

6.7 Transplanting seedlings and wildlings ....................................50


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6.8 Care of planting material ........................................................ 536.9 Selection of plant material and preparation for planting out ...56

7 WORK AT THE SOWING AND PLANTING SITE....................... 587.1 Site preparation ..................................................................... 587.2 Transport and storage of planting material ............................. 617.3 Planting out ............................................................................ 62

8 CARE OF YOUNG TREES .........................................................648.1 Protection against damage ....................................................648.2 Maintenance practices ........................................................... 65

APPENDIX 1: Glossary of terms....................................................... 67APPENDIX 2: Latin names ............................................................... 70APPENDIX 3: Calculation of the amount of seed needed for direct

sowing .......................................................................71APPENDIX 4: Calculation of the number of seedlings and space

required in the nursery ...............................................73APPENDIX 5: Seed Suppliers........................................................... 75

RECOMMENDED FOR FURTHER READING ................................... 77

REFERENCES ................................................................................... 78


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1 INTRODUCTION

Trees are of vital importance to people. They provide many important

products, including food for humans and animals, timber, fuel andmedicines. At a small scale trees influence the environment and assuch the living conditions around a farm. For example, they provideshade and protection from the wind and they play a vital role in fightingsoil erosion and sustaining soil fertility. At a large scale forests areimportant for the global climate, for protecting soils which retain rainwa-ter and thus preventing floods to occur.

All over the world not only whole forests but also free-standing trees arebeing cut down by people in their search for timber, firewood or land forother uses. Uncontrolled fires also destroy many trees. Deforestation isa serious problem, for example: Floods occur and erosion is an impor-tant problem having disastrous effects on agriculture. The living environ-ment, food supply and income of people are disturbed.

Good management of trees and forests is necessary to make resourcessustainable. Trees can well be integrated in agricultural and animal

husbandry systems. Therefore it makes good sense to encourage andsupport local initiatives to plant trees.

This Agrodok is written primarily for farmers and extension workers. Inorder to develop local methods of propagating and planting trees it isvital to collaborate and exchange knowledge. This Agrodok providesinformation on important practical and organisational aspects of treegrowing, which makes it good to use as a manual. Simple, low-cost andlow-input methods and techniques are being emphasized.

The differences between different areas of the tropics are enormous,therefore it is impossible to give detailed information which applies to alllocal conditions. Readers are strongly advised to search for localknowledge on trees and combine this with the information in thisAgrodok in order to make the right choice for the readers specificsituation.

The chapter order in this Agrodok follows the steps you need to take

when propagating and planting trees.


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First thing is good planning and preparation which prevents failure anddisappointment. Careful choice of tree type, planting location andplanting material is important. In the Chapters 2 and 3 the possibilitiesand factors that need to be taken into account are described. Throughthese the reader is guided to make a good choice. In Chapter 4methods of collecting and treating good quality planting material arediscussed.Chapter 5 and 6 treat the farm nursery. Two questions are delt with:How to set up a farm nursery and how to run it.Chapter 7 is devoted to planting out the young trees. Important is thepreparation of the location, storage and transport of planting material.After planting the young trees they have to be cared for, this is delt with

in Chapter 8.At the back is a glossary of technical terms used in the book. Examplesof calculations are given, as well as a list of seed suppliers.

You can contact Agromisa if you have specific questions. In your letteralways include information on local climate, tree types, soil types andother important factors. You can find Agromisas address on the coverof this book.


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2 CHOOSING THE RIGHT TREE TYPE AND PLANT-ING LOCATION

Trees do have many different functions, they can be planted in variouslocations and for many purposes. The choice of tree type and locationmust be made carefully, based on functions needed. The limiting factorsneed to be considered in order to make the best choice.

2.1 Functions of trees

The more functions a tree has the better it is. A tree can provide prod-ucts, represent a financial reserve or improve living conditions. Variousmembers of a household may have different expectations. For example,a man might see a tree as a way to earn money by selling its wood. Fora woman the same tree might be an important source of food or fire-wood. In order to ensure that a tree fulfils the expectations, it is impor-tant to know what the requirements of the various people involved are.An overview of the functions of trees is given in Figure 1.

Wood pulp and paper

Fibers

Construction materials

Green pesticides

Resin, gum

Dyes

feed

Animal

for people

Food

Oils and perfumes

Art and household articles

Fuel

Medecines and stimulants

Tannin and otherpreservatives

Figure 1A: Products provided by trees.


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Erosion control by plantingalong contour lines

Protection of animals,plants and peopleagainst wind and sun

As border of plot or farm

Investment and saving:future sale of wood cancover high expenditures

Contribution tocommunity culture

Provision of greenfertilizer for agriculture

Conservation andimprovement of soilfertility and watersupply

Influence on climate

by absorbing CO2 andregulating waterbalance

Improvement of

farm surroundings

Maintenance of biodiversity

Decreased production

risk through increaseddiversity of productsavailable

Figure 1B: Services provided by trees.

Most trees fulfil more than one function. An example is the coconutpalm found in southern India, which has more than 200 uses. Suchtrees are called Multi Purpose Trees (MPT's). The functions of a treemay change over time. Certain fruit trees provide food for a number of

years and shadow for livestock, after which they may be cut down forwood.

2.2 Choice of tree type

When you have decided the functions that a tree must fulfil, you have tochoose a suitable tree type. For each particular function there will beone or more tree types which are suitable. When choosing a tree you

need to consider the following points:


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1. Characteristics a tree must have in order to perform the functionsrequired.Local farmers and forestry services usually know the characteristicsof local tree types. If you are clear about the characteristics a treemust have, it will be easier to make a choice for the right type oftree.

2. The conditions required by a particular tree type.In order to grow well each type of tree requires specific conditions.You need to consider moisture, nutrients, soil structure, vegetation,light and climate (temperature, rainfall, wind).

Local trees found in the area often make the best choice as they have

already adapted to the local climate and conditions. Planting material isalso often available locally.

Sometimes it is possible to choose a tree which is not native to the area.In that case you must ensure that the requirements of that particulartree are met by local conditions where the tree will be planted. Sometrees can tolerate infertile or dry soil, others cant. A disease or pest maybe a problem in the area and a particular tree type may be susceptible.Look at the trees already growing in the area, and check in which kind of

soil they do best. If the conditions under which a tree type grows wellare found in the location required, then a tree will probably do well there.Disadvantages of using non-native trees are that planting material oftenhas to be purchased and there is often not enough available.

2.3 Choice of location for tree planting

Once you have decided on the tree type you need to decide on the

location for planting. Often the desired function will determine thelocation: When a tree type has been chosen in order to prevent erosionit has to be planted at the place which is susceptible to erosion.

Some locations are not suitable at all for growing trees, e.g. areas withsaline soils, at high altitudes, with much wind, with irregular rainfall, orwith sandstorms. If you intend to plant trees in an area where trees havedisappeared before due to felling, animal grazing, pesticide use or fire,then you need to be sure that you can avoid that happening again.Figure 2 illustrates that there are many locations on a farm where trees


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can be planted. Fruit trees from which fruit can be picked regularly arebest planted close to the house; trees for livestock feed are best plantednear grazing fields; trees for firewood can be located further away fromthe farm.

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1) in and around the farmyard

2) in fields between crops

3) along the edges of fields, or in and around grass fields4) in blocks on agricultural land

5) on fallow land

6) in areas of natural woodland

7) on terraces or ridges, along contours on steep slopes

8) along paths or tracks, on common ground

9) along ditches, canals or rivers

10) in erosion gulleys

Figure 2: Planting locations for trees (After Weber & Stoney, 1986)

Bear in mind that it requires a lot of effort to grow trees successfully onpoor soils. However, once trees have gained a footing on these soilsthey will improve fertility and structure of the soil. They add nutrients andorganic material to the soil from their falling leaves and branches, andtheir roots break up compacted soil. (See also Agrodok No. 2: 'Soilfertility').

Finally try to choose a place where a tree will cause no problems forothers, for example because of the shadow it casts or by decreasing


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crop yields through competition for water. It may be worth consultingneighbours to avoid conflicts.

2.4 Limiting factors for tree cultivation

Although growing trees can have many benefits, you must also take thelimiting factors and possible negative results into account:

Some trees may be poisonous, e.g. the flowers of the ornamentaltree frangipani are poisonous. A tree may increase the risk ofdisease or pests for other plants or animals. In Kenya the tree

Lantana camerais a hiding place for tsetse fly, which can infecthumans and animals with sleeping sickness. Falling branches,surplus leaf material and heavy fruit can also cause damage.

A considerable drawback to cultivating trees is that they onlybecome profitable after a fairly long period. It is often a number ofyears before the trees provide the desired products or services. Inthese years before getting profit, tree cultivation takes up land, coststime and money, all of which you can no longer use for other formsof cultivation.

There are risks when you cultivate trees: these risks must beacceptable. Careful planning and well considered choices willreduce the risks. Generally speaking it is a good idea to plant avariety of types using several methods (see Chapter 3) in order todecrease the risk of tree loss.

There is a risk that the demands from potential users may changein the period between planting the tree and it becoming productive.Sometimes these limitations can be overcome, e.g. by planting fastgrowing types, or by not using valuable agricultural land, but plant-

ing trees on the edges of farmland or in the farmyard. National and local laws might be limiting, but must be respected.

Before planting trees the ownership rights for the planned locationmust be clear. It must be known who has authority over the tree forthe whole period from planting to harvest. Where land is not ownedthen measures must be taken to ensure that the rewards arisingfrom the trees planted can also be enjoyed. State laws concerningtrees on the land must also be respected. For example, felling maybe prohibited or reforestation may be obligatory where erosion is aproblem or certain tree species are becoming rare.


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3 PROPAGATION METHODS

The aim of this chapter is to enable the user of this book to make a well

informed choice which are the appropriate propagation methods andplanting materials.

A well-thought out choice will increase the chance of success. Even so,the fact remains, that it is best to spread risk by using a number ofmethods and types of planting material.Trees can be propagated by natural or artificial methods, which aredescribed below. Technical details are described in later chapters.

3.1 Natural regeneration

Natural increase, known as natural regeneration, can be stimulated byprotection and improving conditions for growth of young trees. Treeseedlings can be helped along by weeding around them. Naturalregeneration through the growth of seedlings often takes place when apiece of land is allowed to lie fallow.

When trees have been cut down, in many cases they have not died.Regrowth from the stumps is also a way of natural regeneration. Leavea few sprouts to grow from each stump, this can bring about rapidreforestation.In an area where natural regeneration takes place the types of tree thatgrow will be restricted to local varieties. The advantages of localvarieties are that they are adapted well to the climate, are resistant tonative pests and diseases and the local people know the trees and theiruses.

3.2 Artificial propatation

When artificial propagation is practised a tree type is selected andmultiplied by using cuttings, wildlings or seed. Cuttings are pieces of the roots, trunk, branches or twigs of a

mother tree. The most commonly used part of a tree for cuttings isthe branch. When correctly planted in the ground cuttings form roots

and shoots, and grow into new trees.


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Tree planting

propagation

natural regeneration

wildling

cutting

nursery

planting

planting

artificialdirect

seeding

material

direct

Wildings are young trees which have grown naturally in the forest orfield. These can be dug up and collected for planting at a chosenlocation.

Seed , wildlings and cuttings can be planted direct at the chosenlocation or they can be planted in a nursery to raise planting materialfirst. (See Figure 3). A nursery is a protected piece of land where youngtrees can be raised under controlled conditions. Once the trees are bigand strong enough they can be planted out where they are required.These different ways of artificial propagation are discussed individuallybelow.

Figure 3: An overview of the propagation methods

Direct planting out of cuttings

Propagating trees from cuttings requires some effort. The cuttings haveto be taken (See Chapter 4) and might need treatment against disease.Taking cuttings can damage the mother tree. Another problem of takingcuttings is the high risk of serious plant shock. This risk is high becausethe cutting is usually already quite developed but is not able to provideits own water or food requirements. Cuttings require moisture in order todevelop roots and branches. On the other hand, cuttings have a numberof advantages: it is easy to collect many of them, and they are easy to

transport. If large cuttings are used an advantage is that they will quicklygrow above weeds and be too large for animals to eat.


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Tree types which are suitable for propagating from cuttings in warmhumid areas include yellow cassia, calliandra, dwarf poinciana, coraltree, poro and mother-of-cacao (Gliricidia).

Types which are suitable for raising from cuttings in arid areas includeacacia, casuarina.Tamarisk, euphorbia, lucky bean, prickly pear, jujube, African bdellium,hibiscus and horseradish tree can be used for cuttings in both humidand arid areas.

Direct planting out of wildlings

In order to make the chance of success as high as possible whenplanting out wildlings, the conditions at the planting site must be assimilar as possible to those where the wildling was found. Light condi-tions, soil type and humidity must be taken into account. As wildlings arehealthy young trees which are chosen precisely for their strength, if theyare planted at a suitable site the chance of success is high. It is oftendifficult to determine what type of tree a wildling is and, in forests withthick undergrowth, wildlings are difficult to find and dig up intact. Theroots of wildlings are easily damaged during transplanting which meansthey are often not strong enough to survive a dry period if this starts toosoon after transplanting.If you decide to use wildlings, then a choice must be made betweentransplanting bare-rooted material or plants with a root ball. The advan-tages and drawbacks to each method are listed in Table 1.

irect seeding

When you apply direct seeding you sow the tree seeds direct at thechosen location. This method requires less work than other methods.You need to collect seeds (See Chapter 4) and prepare the soil at theplanting site (See Chapter 7), planting out is not necessary.Direct seeding is more succesful with fast growing trees becausecompetition with weeds will occur. Losses are likely to occur: people oranimals might damage young trees, or climate conditions, like drought,might cause them to die. The calculation of the amount of seed neededfor direct seeding is shown in Appendix 2.


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Raising planting material in a nursery

A nursery requires labour and land. On the other hand, cuttings, wild-lings or seedlings can be raised under protected conditions to become

well developed and strong planting material. These young trees will bebetter able to withstand difficult conditions than those grown up undernatural conditions. In arid areas planting material can best be raised in anursery. Fruit trees are often raised in farm nurseries. Technical detailson designing, constructing and running a farm nursery you find inChapter 5 and 6.

Nursery planting material can be raised in containers or in the soil.Seedlings raised in containers are planted out by removing the con-

tainer, but leaving the soil around the roots. Seedlings raised in theground are dug up, and soil clinging to the roots is shaken off beforeplanting out.The advantages and drawbacks to these two types of planting materialare listed in Table 1.

Planting material in containers is good to use for difficult plantinglocations, for example where the soil is dry or infertile. Potted plantshave a reserve of nutrients and water in the soil surrounding the roots.

However, it is not worth spending time and money on raising seedlingsin pots if raising them in the ground produces equally good results. It is


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quite possible to raise a combination of seedlings in the ground (bare-rooted) and in pots.

If it is impossible to set up a nursery yourself it may be possible toobtain planting material from a nursery in the area. One advantage isthat the planting material obtained will already be quite big. However,often it is expensive and more likely to be damaged during transport.You should check the quality of the trees carefully: Do the trees look healthy: strong twigs and leaves? Do the trees have good roots: straight main roots with lots of

smaller branches?

Always ask if you can open a container to inspect the roots of a tree.Nurseries may not always be able to supply the tree types you require. Ifthis is the case, it is not advisable to choose other types of which youare not sure they will fulfil your requirements.

3.3 Conditions for propagation methods

There are a number of conditions that influence the choice which

propagation to use. These conditions are: Tree type, availability ofplanting material, local conditions, disturbance at location and commer-cial and technical considerations. They are discussed below:

Tree type

Each tree type has a form of propagation which is most suited to it.E.g. some tree types are easy to propagate from seed, from others

seed is difficult to obtain. Fast growing types could be sown direct at thechosen location, slow growing types could be better raised in a nurseryfirst.

The local forestry service will probably be able to provide information onthe best form of propagation for the tree type required.Natural regeneration is suitable when no specific type of tree is required,because only naturally occurring trees will occur. In contrast, wheredirect seeding and planting are done, both the tree type and the location

can be chosen.


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An example: In dry areas of Africa good results have been achieved bydirect seeding with Borassus aethiopum, cashew and acacia. Theseedlings form a long root very quickly and grow quickly above theheight of surrounding weeds.

Availability of planting material

If you want to use cuttings for planting then there must be a suitablemother tree which can provide cuttings. Natural regeneration dependson the presence of trees with seeds in the area.

The availability and price of seed may also determine which method is

chosen. If seed is scarce then it is advisable to raise seedlings in anursery before planting them out. Losses will be less than by directseeding.

Local conditions

The most important local conditions which affect the growth of trees are:soil fertility, amount of erosion, ground compaction, rainfall, temperature,

humidity, slope and altitude.On steep slopes or fragile soils it is best to leave existing vegetationundisturbed. Natural regeneration is then the best form of tree propaga-tion.Where the rainy season is short or there is drought direct seeding isoften not successful.

Sometimes measures can be taken to influence the local conditions,e.g.:

Soil can be tilled to break it up so water can infiltrate, germination ofseeds is stimulated and roots can easily penetrate the soil.

The seeds of some trees can be mixed with animal fodder. Theseeds are then spread in the animals dung, and germinate in thefertile environment provided by the dung.

Small water harvesting systems can be made to collect rainwater ata certain spot where the tree is planted. See Agrodok No.13: Waterharvesting and soil moisture retention for detailed information onthese structures.


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Disturbance of the location

Natural regeneration, seeding and planting at the chosen location are allsusceptible to disturbances in the form of fires, flooding, animal grazing

and human action (burning, tree felling, occupation of land).

Natural regeneration is often not recognized as a form of land-use,which means that other people may occupy the land for their own use. Ifthe risk of this happening is high it is better to choose an alternativeform of tree planting. Animals can be kept out by constructing a fencearound an area. In areas with a lot of shrubs it is possible to sow seedsbetween thorny branches to reduce the chance of seedlings beingeaten. Choose tree types which are unpalatable for animals.

Commercial and technical considerations

If you want trees to provide products or services within a short time thendirect planting out of wildlings or cuttings (or seedlings if they areavailable) will provide the best results. These forms are already quitelarge and will reach maturity more quickly than trees grown throughnatural regeneration, seeding or nursery raising. An example is planting

a living fence using cuttings.

The scale on which planting is to take place also determines the choiceof planting material. Wildings and cuttings are often only available inlimited amounts. Seed is often available in larger quantities.

One advantage of natural regeneration and direct seeding is thatplanting out is not necessary. This saves a lot of work and the roots arenot damaged, and the young plants are not disturbed.

3.4 Practical examples

A good example of natural regeneration combined with grass cultivationcan be found in a hill area of Nepal. A guard is used to protect the areafrom animal damage. Cultivation takes place over a five year period. Inthe first year no grass is harvested as the seedlings are still too young tobe identified. After the first year grass is harvested, weeds are removedand undesirable trees are removed. This work is done after the


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monsoon period. After a further four years the trees are large enough toharvest. The harvesting of other products throughout the four yearsmeans that seedlings from these years are lost, but there areadvantages: there is less competition and runners are not put down,whereby the branches grow more quickly and in good shape.

In Papua New Guinea natural regeneration was not successful due tolack of clarity concerning ownership rights and lack of supervision.Areas where regeneration has taken place have been lost through fireor illegal land invasions by farmers. This shows that for naturalregeneration to succeed it is necessary to have the cooperation of allpeople involved in the exploitation of an area.

In areas used by pastoralists in Africa planting trees has had littlesuccess. For example, an area of 1,700 hectares was afforested inSenegal. Despite the amount of effort and investment made, tree growthwas minimal. This was mainly due to the failure to implement protectivemeasures against animal damage. As a result of these lessons astrategy now more commonly employed is to protect a selected areafrom livestock so that natural regeneration can take place and treecover is eventually restored.

In a tree planting scheme in Zimbabwe, leucaena seedlings bought froma nursery and planted out turned out to be too small. Insufficientweeding was done and the seedlings were trampled underfoot as theywere not visible. As a result they did not survive. Use of larger seedlingsand leaving planting out until later have proved to be successfulstrategies. Planting out mulberry directly in the soil led to large lossesbecause care in the field required too much labour. The solution herewas found by raising the cuttings in a nursery until the roots were

sufficiently developed.


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4 COLLECTION AND TREATMENT OF CUTTINGS,WILDINGS AND SEEDS

Using good quality planting material increases the chance of gettingstrong young trees. A good, healthy tree usually produces good offspring: you need to

ensure that you collect your cuttings, wildlings or seed from a goodquality mother tree.

The origin of planting material is important: use only plantingmaterial which comes from areas with similar growing conditions tothose where you are going to plant trees.

4.1 Mother trees

Trees which are used for propagation material are called mother trees.The suitability of a tree for providing offspring depends on the functionsand characteristics required of a tree. A mother tree can pass oncharacteristics such as rapid growth rate, crown shape, fruit size andresistance to disease and pests to its descendants.

The degree to which offspring resembles the mother tree depends onboth the genetic material passed on and the conditions where the treesgrow. Cuttings, which are raised directly from the mother tree, showalmost complete similarity to the mother tree.In the case of wildlings it is often unclear from which tree(s) the wildlingis a descendant.The characteristics of seeds are influenced by two trees (or two flowerson one tree) as they are the result of fertilization. The offspring will notbe completely similar but it always resembles the mother tree.

Because of the similarities between mother trees and the offspring it isimportant to select mother trees very carefully. They cannot be chosenrandomly or just because they are close by or convenient.Try to find a tree stand where a number of the same trees grow andchoose the ones which have as many good characteristics as possible.If the conditions here are similar to those where you intend to plant treesthen there is a good chance that the planting material will survive.You can mark good quality mother trees so that you can recognize themin years to come. It is worth noting bad trees so that you know which


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ones to avoid. It is also a good idea to make a calendar for collectingand treating local planting material and making a map or note of goodmother trees in your area.

4.2 Cuttings

In most cases cuttings are pieces of branches, twigs or the roots of amother tree. It is important to know which parts of a specific mother treecan be used best for cuttings, as well as how to take cuttings and whattreatment both cutting and mother tree require after a cutting has beentaken.

Always use clean tools: disinfect your cutting tool in boiling water beforeuse. Never use a blunt axe or machete for taking cuttings. If a cut is notsmooth and made cleanly, rot may occur which will not only lead to thedeath of the cutting but also of the mother tree. The cut must be smoothand sloping downwards so that rain water runs off the cut and preventsrot from occurring (See Figure 4).

1-3 cm

50-100 cm

X: base of the cut

Figure 4: Making cuttings (From Weber & Stoney, 1986).

Only shoots which are older than one year have buds which can de-velop roots. It is best to take cuttings from the end of a branch with afew growth buds, and preferably from a shoot which is resting. This will

be in the dry or cool season. Sometimes you need to mark the foot ofthe shoot so that you know which end will go into the ground.


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Cuttings usually vary in length from 20 to 100 cm, depending on the treetype. The best thickness for a cutting also varies, but is usually between1 and 3 cm. Here are a few examples of cutting length: cola 15-20 cm;cashew 20-30 cm; citrus, avocado 30-50 cm and diameter of 1.5 - 4 cm.In Costa Rica woody cuttings of 2 - 2.5 m in length are used.

The leaves are often removed from cuttings so that transpiration isreduced which prevents the cuttings from drying out. Before planting thecutting it is a good idea to cut off the bottom again with a sharp knife ormachete (See Figure 4). The surface may have been damaged at thetime the cutting was taken and a new clean surface increases thechances of the cutting taking root. The base of large woody cuttings is

usually cut off at a slant. Alternatively, the bark around the base can bescraped away to encourage root formation.Large woody cuttings can usually be kept for up to a week beforeplanting. Store them in a cool shady place under damp jute or gunnysacking, grass or leaves. Small cuttings cannot be kept for so long.They should be kept bundled together in a damp cloth with the base indamp soil or water.

It is possible to stimulate mother trees of some tree types to form extra

shoots which can be used to take cuttings. Techniques for doing thisare: coppicing, pollarding, pruning, (mound)layering and ringing.

CoppicingCoppicing is done by cutting the tree trunk off close to the ground sothat new shoots grow out of the cut surface. These shoots can thenbe cut off and used for planting. For example, papaya is cut off at aheight of between 50 cm and 1 m. The shoots are cut off when theyare about 40 cm in length. Once planted out the shoots will bear fruit

after about 11 months (See Figure 5).

PollardingPollarding is similar to coppicing but done higher up. The brancheson a tree are cut back to a height of about 2 metres. This is a com-mon way of taking stakes from a living hedge. The stakes are thenoften replanted in the same hedge or used for another nearby hedge.A similar method is also used for mother-of-cacao and Erythrina spp.


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a: trunk; b: trunk is cut down; c: coppice; d: cutting.

Figure 5: Taking cuttings from papaya (From: Aumeeruddy & Pinglo, 1988).

a

bc

d

d

50-100 cm

40 cm

A: weaving/plaiting two shoots;

B: buds on the woven shoots develop more shoots;

C: cuttings are taken from the new shoots, leaving two behind for further

weaving / plaiting.

Figure 6: Weaving shoots to promote growth of cutting (From: Aumeeruddy &Pinglo, 1988).

A B C


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PruningPruning stimulates buds to start developing shoots. These shootscan then be used as cuttings. Pruning is selective cutting back of atree to encourage the growth of a few shoots to be used for cuttings.Sometimes branches can be trained by bending them so that theygrow in the shape or direction desired. For example, a pollarded treecan be pruned so that just two shoots are left. These shoots can bewoven or plaited together so that the number of new shoots in-creases. By doing this the mother tree will also recover more quicklyfrom pruning and form newer shoots more quickly (See Figure 6).

Layering

Layering is done by training branches of a tree in such a way thatthey are bent towards the ground and then anchored so that newroots form. Once the roots are sufficiently developed these branchescan then be cut off from the mother tree. The best branches tochoose are ones that are not too old and which are growing upwardsinstead of out towards the side. The branch can be bent downwardsusing weights or wires pinned to the ground. A form of this techniqueis used to propagate coffee bushes in Indonesia. The main stem iscut off at a height of 1.5 m above the ground. The side branches then

hang down and can be used to train along the ground. Thesebranches form new roots and the ends of the new branches are thenstaked to help them grow upwards. Once they are big enough theyare cut off (See Figure 7).

Figure 7: Layering (From: Geilfus, 1989).


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A: trunk,

B: cut off trunk.

C: coppice,

D: cutting.Figure 8: Mound layering (From: Aumeeruddy & Pinglo, 1988).

Mound layeringGuava is propagated in Zaire using the mound layering system(See Figure 8). The tree trunk is cut off very low to the ground (8A).The cut off trunk surface is then covered with soil and new shootsgrow out (8B). The soil encourages the shoots to grow roots (8C).After a few months the shoots are pulled up from the trunk and areplanted out (8D). This practice is also used in Indonesia with cinna-mon trees.

A B

C D


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Ringing

Ringing is a technique which can be used for tree types which aredifficult to propagate using the above methods. This method is usedin particular with citrus, mango, lychee and avocado. One or twomonths before taking a cutting (about 50 cm long) a ring of barkabout 2.5 cm wide is cut away down to the wood (near to where thecutting will be taken). The leaves near the ring are cut off. The ringcan be protected with a band of plastic or aluminium. This methodallows a cutting to build up reserves as the nutrients formed by theleaves can no longer travel further down the branch (See Figure 9).

Figure 9: Ringed branch (From: Geilfus, 1989).

The cutting can develop roots while still on the tree: this is called alayer. In this case the ring can be protected by surrounding it with aplastic bag containing moist earth or moss. This method is also calledair-layering or marcotting.

4.3 Root cuttings

Tree roots can also be used for taking cuttings. In order to speed up thedevelopment of root cuttings the end of a tree root is cut off using aspade or shovel. From the piece of root cut off new shoots will form(See Figure 10A). Some tree types such as the breadfruit tree can bepropagated by taking root cuttings a few centimetres in diameter cut off

in lengths of 1 m. These cuttings are then put back in the ground in thenursery. After one or two months shoots will form (See Figure 10B).


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Figure 10B: Remove section of root and transfer to nursery (From Longman).

4.4 Wildings

Wildings should have at least 2 to 4 fully formed leaves when you digthem up. Larger wildlings have a stem about the diameter of a pencil.They can be collected in two ways: with and without a root ball.

Wildings with a root ball are dug up by making a cut on either side of theplant at an angle of 45 o using a spade or machete. The plant is thenloosened from the ground holding the woody part of the stem andremoved with the root ball intact, supported by the spade. It is difficult to

dig up small wildlings with a root ball, because the roots are not yetdeveloped.

a: Cut off piece of root;

b: Development of shoot and new roots on root cutting;

c: Cut off shoot where marked with dotted line and dig up new shoot.

Figure 10A: Root cuttings (From Longman, 1993).


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Bare-rooted wildlings are uprooted by first loosening the soil around theroots with a pointed stick and pulling the plant out of the soil carefully byits leaves and the soil shaken off the roots.

The advantages and disadvantages of bare-rooted wildlings and thosewith a root ball are listed in Table 1 in Chapter 3. Wildings with a rootball are generally preferred.

In order to reduce damage to wildlings occurring during digging up,transport and planting out, the primary root (taproot) and large second-ary roots are often trimmed. Leaves except for the top ones can beremoved to reduce transpiration.

It is not a good idea to store wildlings. It is better to plant them out asquickly as possible after digging them up. The roots of bare-rootedwildlings should be protected during transport by covering them withdamp material (earth, jute sacking, palm leaves etc.). Alternatively youcan dip the roots in a mixture of clay and water.

4.5 Seed

Seeds can be obtained by collecting them yourself or buying. You canbuy seeds from traders, forestry services or seed banks usually locatedin research institutes (See the address list in Appendix 5).Any seed you obtain should be labelled with the following information: species, date of collection, origin of seeds, germination rate,

seedlot and location.

The amount of seed you need depends on the number of seedlingsrequired and what percentage of the seed is likely to germinate andform seedlings. Appendix 3 provides an example for calculating thenumber of seeds required for direct sowing. Appendix 4 provides anexample for calculating seed requirements for a nursery. It is advisableto raise more seedlings (about 15%) than are required for planting out inorder to compensate for selection and failure.


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Seed collection

If you plan to collect seeds from local trees choose seeds which arelarge, healthy and ripe. Seeds which have recently fallen are generally

good, but very often the first and the last seeds to fall are either infertile,infected or damaged. Ripeness is indicated in different ways: fleshyfruits often change colour, or the flesh becomes softer. Dry fruits oftenburst open causing the seed to be released.

Methods of collecting seeds and fruit: Pick them up from under the tree (clear the ground under the tree

before ripening); Hit the tree with a stick or shake it with a long hook, catch the seeds

in containers or sheets under and around the tree; Use long-handled cutters or saw; Climb the tree and pick; Pick them from fruit-bearing trees which have been cut down.

Ripe fruit and seed must be collected quickly, otherwise they will beeaten up by animals. In damp areas seeds and fruit which fall on theground are likely to rot.Many types of seed also lose their germination strength rapidly(especially large moist seeds). Fruits must be brought quickly to a dry,well-ventilated place. Never store them in the same bag as the one usedfor collecting them in order to prevent damage from insects, fungus anddamp.

Methods for removing seed from the fruit vary. Sometimes it occursnaturally: the seed pods of some acacia varieties in dry areas disinte-grate when they have dried out, and by shaking them gently the seeds

will fall out. Mango seeds have to be removed from the fruit and cleanedbefore they can be planted.

Dry fruits such as cones and pods often need special treatment(E.g. exposure to the sun to open them) to get the seeds out. If theseeds are in the flesh of the fruit then they can be removed by gentlyrolling or hitting the flesh until it breaks, or by grating the flesh with asieve. Advice on the best methods for removing seed is best obtainedlocally.


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Seed cleaning

Once the seeds have been removed they need to be cleaned thoroughlyto remove all bits of fruit flesh, pod or husk. You can clean seeds by

hand or by using the wind to winnow, as is done with most Acacia spp.and Senna simeafor example.Seeds must be dried to prevent damage from fungal and bacterialinfection. However, extreme heat must be avoided as this destroys theseeds ability to germinate. Do not dry seeds in direct sunlight, but in ashady, well-ventilated place.

Seeds which have been cleaned will vary in colour, size and shape.These need to be sieved in order to remove remaining dirt and low

quality seeds. The best quality seeds are nearly always the biggest.Another way of separating seeds is to cover them with water. The badquality seeds and dirt will float, while the good seeds will sink to thebottom. Remove the good seeds and dry them carefully.

Seed storage

Seeds need to be stored if they are collected at a different time from the

planting season. Some seeds (e.g. legumes) can be stored at normaltemperatures for many years as long as they are kept dry. Most seeds,however, can only be kept for a limited amount of time.

Well stored seeds are kept dry and at a constant cool temperature.Seeds which have been properly dried can be stored in dry containerssuch as pots, boxes or bags. For insulation seeds can be doubly sealedby putting them first in a thick plastic bag, closing it tightly, and thenputting it in a container with a lid. By burying the containers under a

layer of dry soil in a shady place you can keep them at a constant cooltemperature.

Make sure the seeds cannot be eaten by insects or rodents. Label eachcontainer with the usual information and add a note of treatment givenand the date of storage. Check the contents regularly and at the sametime turn the seeds or shake the container.


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Treatment of seed

Some seeds do not germinate easily, they need a treament to stimulategermination. For example some seeds have a very hard or tough coat,

which makes germination difficult. Other seeds rest for a certain amountof time before germination takes place (germination rest).

There are a number of methods of treating seeds to accelerategermination: Soaking:An easy method; soak the seeds for 2 days in cold water

prior to sowing them. This makes the seed swell, breaking thecoating and washing away the substances which delay germination.This method works for many tree species.

Hot water treatment: This removes the hard outer cover of someseeds, leaving a softer covering which the sprout can break throughmore easily. Boil water (about 4 liters for 1 kg of seeds), whenboiling take it off the fire, then immerse the seeds in it. Allow thewater with seeds to cool overnight. Rinse them with clean water thenext day. This method is the right one for Leguminous species asAcacia, Cassia, Prosopis and also for Faidherbia albida. Someseeds must be boiled briefly, e.g. baobab seeds.

Short exposure to a high temperature: E.g. teak seeds will start togerminate when the temperature reaches 40oC.

Scarification: A small piece of the seed coating is torn or cut offwhich helps the sprout to emerge. A simple way of doing this withlegume seeds is to rub them over a rough surface. This needs to bedone so that the coating is scratched but not completely broken.You must also be careful not to let the seeds get too hot, as this willdestroy the sprout. This method works for Leucaena, Juglansneatropica and also Faidherbia albida.

Stratification: Seeds are stored in pots with cool soil which causesthe removal of the substances which delay germination. As this isnot an easy or common method to use, it is not treated further inthis Agrodok. For more information write to Agromisa or ask youlocal forestry service.

It is best to obtain information on treating different kinds of seeds fromlocal forestry services or institutes (See Appendix 5 and list of litera-ture).


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5 DESIGN AND CONSTRUCTION OF A FARMNURSERY

Farm nurseries are used successfully in many areas: in West Kenyaabout a third of households traditionally raise their own seedlings. Theyare usually built on the homestead or on privately owned land.

A nursery should be simple to lay out and require very little in the way ofmaterials and maintenance. The simplest form of nursery consists of afew seedlings in makeshift containers such as old tins, pots or bowlsplaced in the shade of a tree.

If you plan to have a larger nursery it is necessary to think about thelocation, design and construction of it.

5.1 Location of a nursery

By choosing a suitable location and thinking about the layout beforeconstructing a nursery you can make it considerably more efficient. Ifpossible a nursery should be built as close to the house as possible to

make management and supervision as easy as possible.Below is a list of the most important factors which have to be taken intoaccount when choosing the location for a nursery.

WaterThe productive area of a nursery requires between 10 and 20 litres ofwater per square metre daily, depending on the temperature and thesize of the planting material. If rainfall is not sufficient then you mustwater the plants from another source. In this case there must be

enough water available nearby throughout the year. Small nurseriesclose to the house can make use of waste water from the household,as long as it is not too dirty.

SoilThe soil requirements, and therefore also the location of a nursery,depend on whether seedlings are to be raised in seedbeds or in pots.If seeds are to be planted directly in the soil in the nursery then thesoil must be reasonable fertile, rich, deep and well drained. A thinlayer of soil on top of a layer of stones or grit is not suitable. A deep


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but stony soil is difficult, but can be used. Sites where charcoalproduction has taken place in the past or where huts stood previouslyoften make good nursery locations: the soil is rich and there is usuallylittle competition from weeds.If pots are to be used then the quality of the soil is less important:pots can be filled with soil from elsewhere. They can also be placedin a spot where nothing else will grow. Transport of good quality soilfor potting to the nursery means extra work and costs. Try to avoidthis if possible.Table 1 (Chapter 3) lists the criteria which must be considered inorder to make a choice between seedbeds (giving bare-rootedplanting material) and pots (planting material with rootball).

TerrainA nursery is best constructed on fairly flat ground, preferably with agentle slope so that water runs off, avoiding problems of waterstagnation and erosion. The slope should not be steeper than 2%(A height difference of about 2 cm over a distance of 1 m). Where theground slopes more steeply making terraces can be a solution.

Shelter

A nursery must be protected from both wind and sun. A nurseryplaced on a hilltop is likely to suffer from wind which will dry outseedlings. Periods of shade are necessary to prevent overheating. Atree which provides shade, or banana plants placed in the corner of anursery can be used to protect very young seedlings from strongsunlight. It is also possible to build shade constructions when layingout the nursery (See section on nursery construction).

5.2 Design of a nursery

Good nursery management begins with a well thought-out design. It is agood idea to make a sketch before starting. Figure 11 shows a drawingfor the design of a fairly large farm nursery. However, the principles forlayout remain the same for a small nursery. The size of the nursery willdepend on the number of seedlings to be raised. Appendix 4 providesan example of how to calculate the number of seedlings and the amountof space required for them.


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a b cd

e

fg

hi

j

a: prevailing wind direction

b: windbreakc: shed for tools and supplies

d: potting area

e: space for mixing soil

f: compost heap

g: water supply

h: seedling bed, in which seedlings from the seedbeds are planted;

i: seedbed, in which seeds are sown;

j: cutting or pot bed, where cuttings are planted or pots are put.

Figure 11: Example of nursery layout

The nursery beds (for seeds, seedlings, pots and cuttings), are used toraise planting material, either in soil or in pots. The type(s) of beds youmake depend on the propagation method you have chosen.Beds need to be about 1 metre wide and can vary in length. The sizeand shape of the beds must enable watering and weeding to be done

without stepping on them. Paths are laid out between the beds(40 - 60 cm wide).


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In order to make sure the plants are exposed evenly to the sun the bedsshould be constructed in an east-west orientation, if the slope of theground permits this. In this way the seedlings in the middle of a bed willreceive as much sun as those at the edges.

Additional factors which must be taken into account when designing anursery include:

Wind: In areas of strong and dry winds a windbreak must be con-structed perpendicular to the prevailing wind direction. A windbreak canbe a living hedge or a fence (See also Agrodok No. 16: 'Agroforestry'and Agrodok No. 13: 'Water harvesting and soil moisture retention').

Animal damage: A nursery can be protected from wandering livestockby building a fence or hedge around the nursery. Damage from rabbitsor other rodents can be prevented by using wire netting dug into theground.

Space for compost: Compost is needed for the soil in beds and potsand is made from decayed plant material. Compost is made and storedin heaps or pits in the shade. If no shade from trees is available a

screen must be made. There must also be enough space next to theheap to be able to turn the compost while it is decomposing (SeeAgrodok No. 8: 'Preparation and use of compost'). If no compost isavailable, humus can be collected from the forest.

Materials: It is useful to have sand, clay, humus, soil from the forest orpeat available for improving the quality of the soil in the nursery. Polesand stakes are needed for fencing and shade constructions. Tools,including spades and hammers, must also be available.

Potting space: This is needed for filling pots and for potting andrepotting seedlings.

Space for seed extraction and treating cuttings: A piece a ground a fewsquare metres in size is needed for drying seeds which have beencollected and for extracting seeds from fruit and cones. The samespace can also be used for treating cuttings. This is a more importantrequirement in a larger nursery.


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5.3 Construction of a nursery

Begin by preparing the area you intend to use: clear the vegetation, levelthe ground and if possible make a slope with a gradient of 1 - 2%. Markout beds and paths before laying them out. Dig drainage channels ifnecessary.

Seedbeds

The construction of seedbeds in a nursery requires the most attention.Good beds are filled with light soil which is rich in organic material(humus) and has a crumbly (friable) structure. Heavy soil (e.g. clay) is

difficult to work and roots are easily damaged when transplanting. A soilwhich is too light dries out quickly. The soil should be reasonably fertileand free of lime as most seeds germinate best in a slightly acid soil.If necessary mix the soil with sand in a 1:1 ratio. This mixture willimprove drainage and help the seedlings to break through. Whentransplanting this soil mixture breaks up easily which prevents rootdamage.

There are three types of seedbeds: normal, raised or sunken. In areaswith high rainfall where water does not drain away quickly raised bedsmust be used (See Figure 12). A raised seedbed, built on top of a layerof stones, wood or similar material improves root development anddrainage and will suffer less from erosion during heavy rainfall.

In dry areas seedbeds need to be sunken in order to prevent drying outand to collect the little rain that falls. However, bear in mind that erosioncan be a problem in sunken seedbeds. Mark the edges of the beds and

then dig out a layer of soil below the surface layer. Pile the soil you havedug up on to the paths around the bed until the paths are 10 to 20 cmhigher than the bed.The holes you have dug out can now be made into seed beds in the waydescribed below. Make sure that you do not fill the beds right up to thetop edge, otherwise surface soil and seeds will be washed away.

The composition and construction of normal, raised and sunken seed-beds is the same. The only difference is in the final height in relation to

ground level. The final height of a normal seedbed is ground level.


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a: drainage layer

b: water retaining layer

c: root layerFigure 12: Construction of raised seedbeds (From: ILO, 1989).

Construct seedbeds as follows (See also Figure 12):1) Make a raised edge of about 15 to 20 cm high from wood, mats of

woven twigs or bricks and place this in or on the ground. The depthwill depend on the type of seedbed you are constructing.

2) Cover the bottom of the beds with a layer of stones or broken bricks5 cm deep to ensure good drainage.

3) Cover the layer of stones with 2 - 3 cm of soil containing a lot ofcoarse material which retains water well. Use compost or a mixtureof soil and leaves (humus).

4) The top layer of the seedbed consists of fine textured, fertile soil.This is the layer in which the young trees will root. Use sieved fertilesoil, or a mix (1:1) of soil and sand.

5) Trample the beds down so that they are well consolidated. See

Preparation of seedbeds in Chapter 6 for more information.

100 cm

abc

15-20cm


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If you are planning to raise conifers (e.g. pine trees) in the nursery thenyou need to use soil from stands of young conifers. This soil containsorganisms which the seedlings need in order to grow. Legumes alsogrow better if you use soil in which older legumes of the same type arealready growing.

Cutting beds

In addition to the steps mentioned above, beds which are to be used forraising cuttings require special preparation: most cuttings root best in asoil mixture of sand and well decayed compost (with a volume ratio of2:1 or 1:1). If necessary sterilise the compost before use by steaming it

in large containers or spreading it out to dry in the sun, preferably underblack plastic.

To help cuttings take root keep the temperature and humidity constantby stretching a transparent plastic cover over the beds. This is notnecessary for cuttings which root easily.

Pot beds

It is very important that the bottom of the bed is flat and even. A framecan be built around the bed to keep the pots upright. This can be madefrom stones, bamboo, poles, wood, bricks, rope or of earth.

Place the pots in straight lines of equal length in the pot beds; thismakes transplanting and counting easier. Always place the pots uprighteven though it is often easier to lean them against each other. If the potsare not straight the seedlings will also grow crookedly, and the roots

may be deformed, as the roots at the edges tend to grow downwards.

Shade constructions

Shade constructions can be built to prevent seedlings from drying out.You can make a structure from poles with grass covering (See Figure13A), where you can adjust how much shade or light the seedlingsreceive. You can also bend branches to form arches over the beds or

toform tall shades next to the beds. Mats made from sorghum or milletstems, bamboo or grass can be laid on frames made of branches,


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A

B

A: the amount of grass determines the amount of shade

B: roll-up mats

Figure 13: Shade constructions (From: Nieuwenhuis, 1990).

stakes or rope about 50 cm above the seedbeds (See Figure 13B).These mats can be rolled up when they are not necessary. In large,permanent nurseries it may be worthwhile building high shade construc-tions which you can walk under upright.

Shade mats must still allow about half the total amount of sunlight topenetrate so that the seedlings can grow well. The mats must be easy


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to remove as shade is not required all the time. Bind the materialstogether with rope so that the mats can be rolled up when not needed,or when the planting material needs attention.Where hail and heavy rain are a problem, more closely woven or doublemats can be used at night or during storms. If you need to protectseedlings against frost, place protection as close to the ground aspossible.

Maintenance

It is important to maintain your nursery well: check drainage channels,paths and terraces regularly for damage or wear. Carry out any repairs

immediately, especially during the rainy season or if the nursery is builton a slope. Check fences regularly for holes. After planting out replacethe soil in the beds or pots to prevent spread of disease and pests.


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6 ACTIVITIES IN THE FARM NURSERY

Once you have designed and built your nursery you can start the

nursery activities. It is important to plan and prepare the activities wellso that you can carry them out in a logical and efficient manner toensure that planting material will be available when it is needed.Activities include sowing in pots and seedbeds, planting cuttings andtransplanting seedlings and wildlings. Care of planting material is alsoimportant. Last activity is the selection and preparation for planting out.

6.1 Planning

In order to maximise the chance of survival of seedlings once they areplanted out in the field, the timing of work in the nursery is very impor-tant. Organise the nursery in such a way that good quality seedlings forplanting out are ready at the beginning of the rainy season.The mistake is often made of only starting nursery activities once therainy season has begun. This saves work watering, but the conse-quence is that seedlings are too small and that they are not planted out

until the dry season has already started. As a result many young treesdie in the field.In subtropical areas sowing needs to take place from six months beforethe rainy season, so that the young trees are ready for planting out justas the rains begin. The exact amount of time needed will depend on thetypes of tree you wish to raise. It is best to obtain this kind of specificinformation locally, from the forestry service or forestry projects in thearea.The amount of labour available must also be taken into account when

planning activities in the nursery. For example, if there are not enoughpeople available when planting out needs to be done then material willbe lost. A division of labour should be agreed upon between the mem-bers of the household. If nursery operations are planned in such a waythat they can be fitted in with other daily activities on the farm thenmanagement of the nursery can be carried out efficiently. For a largernursery, setting up a system for administration and record keeping canbe of help. Make a calendar showing when activities such as collectionof planting material and transplanting need to take place.


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Figure 14 : Overview of propagation methods in a nursery.

pot

po

t

po

t

bed

bed

bed

po

t

po

t

bed

bed

pot

selection

field

seed

cutting

wildling


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This chapter is set out more or less in the same order as that in whichoperations in the nursery need to take place. Seed and cutting beds areprepared and/or pots filled. Then sowing takes place or cuttings aretaken. Sowing can be done directly in pots or in seedbeds first (Afterwhich seedlings are pricked out into seedling beds or pots at a later dateif necessary). Cuttings and wildlings can first be transplanted to thenursery and/or potted up. Whichever method is used the care given tothe planting material is of utmost importance: it is from this material thatplants will be selected and prepared for planting out.The techniques described below (sowing seeds, growing cuttings andplanting) can also be used outside the nursery in the field. See alsoChapters 4 and 7.

6.2 Preparation of seedbeds

Before seeds can be sown the seedbeds need to be consolidated: thesoil in the beds must be compact so that it does not dry out too quickly.Compact the soil using a roller or a wide plank that you can walk over.You can test whether the soil is sufficiently compacted by making yourhand into a fist, and then pressing the underside into the soil. When only

a small imprint is left in the soil then it is compact enough.Do not compact the soil in a bed when it is too wet as this can breakdown the soil structure. The surface of the seedbed must remain flat sothat seed is evenly distributed and does not wash down to lower parts,which would result in uneven germination.After compacting the soil rake the surface of the bed so that there is atop layer of fine soil. Water the beds one day before sowing.

6.3 Pots

It is possible to buy plastic bags, known as polypots, sleeves or tunnels(See Figure 15). The size of these bags varies, but use ones whichmeasure at least 18 x 5.5 cm when laid out flat. Plastic pots mustalways have a hole in the bottom so that excess water can drain away.Pots can also be made from various materials such as paper, tin, clay,plastic or plant material such as bamboo, banana stems or leaves (SeeFigure 16).


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30 cm

8 cm

a: empty

b: filled

Figure 15: Plastic pot, made from a plastic bag.

A B

C D E

A: Lay bundles of dry grass at right angles across each other,

B: Place a bottle or jar in the middle,

C: Bend up the grass. Dampen the grass to make it bend more easily,

D: Plait the top and bind the side with fibre,

E: Remove the container to leave the basket.Figure 16: Making pots from grass (Adapted from Douglas & Hart, 1984).

A B


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Buying plastic pots costs money, but reduces labour costs. Making potscosts less money, but involves more work.For raising seedlings you can also use seed trays instead of pots. Seedtrays can be made from old washing bowls, tubs, car tyres, tins orcontainers. They are usually filled with very light earth, such as riversand which can be kept wet all the time.

Filling pots

Soil for filling the pots should be: Loose textured and light for good root development, but, a ball of the earth must not fall apart when picked up.

If you press some moist earth together in your hand and it stays inshape then it is usually suitable for filling pots. It is difficult to give astandard mixture for soil for pots, because the quality and type of soilvaries from place to place. However, a commonly used mixture is 3parts topsoil, 1 part humus-rich soil (or compost) and 1 part sand.

Always sieve the soil to get rid of lumps and stones. Make a largescreen from wire mesh (with 1 cm holes) stretched over and fastened toa wooden frame. Lean the sieve against a support so that it is at anangle and shovel the potting soil over it so that it falls through the sieve.Lumps which do not go through the sieve can be dried and crumbledapart. If the potting soil is dry, water it and turn it 3 to 4 days before youplan to use it.If you know the soil contains diseases or dangerous pests it is a goodidea to sterilise it. Spread the soil out and let it dry in the sun underblack plastic sheeting.

Fill pots in stages, and press the soil down each time. If you fill pots tothe top in one go and then press down at the top air holes are likely toform in the pots. Once filled leave the pots to stand for a few days. Thesoil will sink down (settle), leaving enough room to plant a seed andcover it. It is important to fill pots carefully. Once filled, pots can be usedfor sowing seeds, or planting seedlings from seed trays, wildlings orcuttings.


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100 cm

6.4 Sowing in beds

When sowing in beds the following factors are important: method ofsowing, density of sowing (spacing), depth of sowing and covering theseed.

The principle behind all sowing methods is to spread seeds asevenly as possible over the seedbed or field. The distance betweenseeds depends on the plant type. Leave a space of about 8 cmaround the edge of raised seedbeds without seeds, as the edgeoften crumbles away.

Common methods include: pit-sowing, row-seeding, board-sowing andbroadcast sowing.Pit-sowing (planting each seed separately) is only suitable for largeseeds. For example, teak seeds are sown individually in holes 10 to15 cm apart. Spread the holes out over the entire seedbed. Anotherform of pit-sowing is when you sow a seed for one fruit tree on the farmplot.Row-seeding is the best way to sow seeds in a seedbed. The rows canbe made using a drilling board on a prepared seedbed.

For board-sowing a drilling board is used to makes holes the correctdistance apart and in the correct pattern (See Figure 17). This method isquick and can be used for both large and small seeds.Broadcast sowing is used for planting small seeds, especially whenthese will be pricked out and transferred to pots later. Broadcast sowingusually produces about 25% more seedlings per area, but weeding andpricking out are more difficult.

Figure 17: Drilling board, a plank with pegs at regular intervals


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Sowing density varies depending on the plant type, the size of theseeds and survival chances. Sow seeds at a density which willproduce sufficient seedlings per surface area. Never sow toodensely, as too little space will prevent seedlings from growing.Small seeds (e.g. Eucalyptus spp.) are mixed with fine sand in asand-seed ratio of 2:1. This makes even sowing easy and preventsseeds being sown to densely.

Sowing depth is generally twice the diameter of the seed. Forexample, seed with a diameter of 3 cm is sown at a depth of 6 cm(See Figure 18). If seed is sown too deep it is more difficult for theseedling to break through the soil surface.

a

a

Figure 18: Correct sowing depth

After sowing, the soil in the seedbed must be pressed down with a roller,a board or a spade (shovel). Seeds need to be well surrounded by soilin order to be able to germinate and then develop roots.Cover seeds as quickly as possible after sowing. This is especiallyimportant with small seeds, which blow away very easily. Cover seedswith loose material, such as coarse sand or very fine gravel, which areeasier for the seedlings to break through. After covering the seeds,

press the seedbed down again so that the seeds do not move when thebed is watered.

6.5 Sowing in pots

Seeds of tree types which germinate easily can be sown directly in pots.A good example is acacia. The larger the container the larger the

seedling can grow in the same pot. Choose a pot therefore that willenable the seedling to grow to the desired size. The number of seeds


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you plant in one pot depends on the germination percentage and theamount of seed you have available (See Table 2). See Appendix 3 forhow to calculate the germination percentage.

Table 2: The number of seeds per pot depends on the germinationpercentage.Germination percentage (%) Number of seeds per pot

> 80 150-70 240-50 320-40 4< 20 5

If you have a lot of seed available, then you can sow quite a few seedsin each pot. You will probably get more seedlings in each pot, thin themout so that one strong and healthy seedling remains in each pot. Pots inwhich no seeds have germinated can be used to plant extra seedlingsthinned out from other pots.For very small seeds use a sand-seed mixture (2:1). Dip a small(paint)brush in water, then in the sand-seed mixture and spread the

mixture carefully over five pots which are filled with soil. For eucalyptusseeds this will produce a maximum of 4 or 5 seedlings per pot.

6.6 Planting in cutting beds

Cuttings need to be planted in moist soil. Just before planting removeabout 1 cm from the lower end of the cutting, making a clean diagonalcut. This will encourage root formation. Push the cuttings into the soil

vertically or at an angle, until about 3/4 of the length of the cutting is inthe soil. Make sure you do not plant the cuttings upside down!Plant the cuttings in rows about 20 cm apart. The cuttings in one rowshould be about 25 cm apart. After planting, water the bed again.If conditions are very dry, stretch a transparent plastic sheet over thecutting bed to increase air humidity. You should lift the plastic regularlyto ensure that fresh air can circulate. Cuttings which root easily do notneed to be covered with plastic. Cuttings with leaves will form newshoots after about 2 to 4 weeks. For cuttings without leaves new budswill appear on the surface of the cutting. At the same time the first roots


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will develop at the foot of the cutting. Once the cuttings have started toroot or grow leaves or buds the plastic cover can be removed.

6.7 Transplanting seedlings and wildlings

At a certain point seedlings in seedbeds have to be transferred to pots(pot plants) or to seedling beds (bare-rooted planting material). This iscalled pricking out, and needs to be done when the seedlings aregrowing too close to each other. A seedbed also only has a thin layer ofsoil, once the roots have reached the bottom of this layer, the seedlingsmust be transplanted. The way in which transplanting takes place is

shown in Figure 19. The same method can be used for transferringwildlings from the forest.Make sure the seedlings will have enough room in the bed to grow tothe size at which they will be planted out in the field. Make the distancebetween rows about 20 to 25 cm. The distance between seedlings inone row should be between 5 and 10 cm.

When pricking out the following points are important: Seedling size: most types are large enough for pricking out about 3

weeks after germination. If the seedlings are too young they arevery delicate and likely to be damaged. If you wait too long then theseedlings become overcrowded and their roots are likely to bedamaged during transplanting.

Drying out: only transfer or prick out a few seedlings at a time (asmany as you can plant in an hour). Work as far as possible in theshade and in a sheltered place out of the wind.

The time of day: it is best to do pricking out late in the afternoon(or in the early morning) to reduce the danger of drying out.

a

b

Check size:

a: true leaves,

b: germination leaves.

A


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Water the seedbed well the

day before pricking out.

1/3

2/3

C

B

Gently loosen the seedlings

from the bed using a

pointed stick.

Grasp the seedlings by the

tip of their leaves. Neverpick the seedling up by the

stem, as this is easily

damaged which will lead to

increased susceptibility to

disease.

Cut the bottom 1/3 of the

young primary (tap) root offwith a sharp knife. This is

necessary if the seedlings

have been left too long in

the seedbed. By cutting the

primary root you prevent it

bending when planting out,

thus ensuring that the root

system develops properly.

E

D


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Keep the roots of the pricked out

seedlings moist: lay them in a

shallow tin filled with a layer of wet

soil, wet sacking or moss and cover

the roots with moist material as

well. Do not place the seedlings in

pots of water; this will wash away

the fine soil and make the roots

cling to each other. You can give

the roots extra protection by

dipping them in mud.

Make sure the hole for planting is

wide enough and deeper than the

length of the roots.

Make sure there is enough room for

the roots to spread out into their

natural position, and that they are

not bent or twisted. Plant the

seedling upright and a little deeper

than it was in the seedbed.

The hole in which the seedling is

planted can best be filled with a

mixture of finely sieved soil and

sand. Press the soil down well so

that the roots can take up moisture

from the soil.

F

G

H

I


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The beds or pots must be watered

and kept in the shade immediately

after transplanting has taken

place.

Figure 19: Pricking out seedlings, figure A to J (From: ILO, 1989).

6.8 Care of planting material

Protection and care of planting material involves the following steps:

WateringThe beds must be watered regularly. Always check how wet the soilis before watering. Where the plants are in pots lift up pots fromdifferent parts of the bed to check how moist the soil is.When watering containers or seedbeds which have just been sown

use a watering can with a fine spray head so that the seeds and theircover are not washed away. During the germination period youshould water a little and often. Keep the seedlings moist but notsoaked as stagnant water and high air humidity increase the chanceof disease. As soon as the plants are bigger they can be watered lessfrequently and using more water at one time. Larger seedlings can bewatered using a hand or garden hose which is quicker, although lesseffective than using a watering can with a spray head. Make sure thatwatering is always done thoroughly so that the lower soil stays moist

for a few days even when the top layer is dry.

ShadeWhen seeds have been sown or seedlings, cuttings or wildlings havebeen planted or transplanted, shading is necessary to prevent dryingout from taking place. Shade mats can be removed gradually oncethe seedlings become established. If the climate is very hot and dry, itis worthwhile ensuring there is half shade for the whole period until

planting out. (See the section on shade constructions in Chapter 5).

J


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WeedingBeds and pots must be weeded regularly. If you wait too long withweeding the roots of the seedlings get tangled up with the roots of theweeds and you will cause root damage when weeding.Young seedlings which have just broken through the soil often lookvery similar to weeds, so you have to weed very carefully at thisstage. Keep paths and hedges free from weeds. A good way to keepweeds down and retain moisture in the soil is to mulch: spread alayer of plant material over the soil (See also Agrodok No. 2: 'Soilfertility management').

Fertilizer

If the soil is light you can use a liquid fertilizer. One part of organicfertilizer (animal dung or compost) in five parts of water is left for10 days. Before spreading the liquid it should be thinned down byadding more water until the colour is that of light tea. Do not usefertilizer which contains a lot of weed seeds.

Root pruningRoot pruning prevents the plant from developing a long primary rootand encourages the growth of useful tough secondary (side) roots.

A seedling with a well-developed root system is better able to recoverfrom the stress of planting out. However, if a tree is to be planted in avery dry or windy area then it is necessary to encourage the growth ofa long tap root. Watering must be continued regularly after rootpruning.

Root pruning is illustrated in Figure 20A. Push a spade down at anangle under the plants and lift them up slightly before pulling thespade out. Make sure that you dig deeper than 5 cm below the

surface otherwise you will kill the plants. If you dig deeper than 15 cmyou will have little effect as most of the roots are shallower than this.Two people should work together, pushing a spade in on each side ofthe row of plants. If you are working alone complete one side of a rowand then do the other side.Root pruning needs to take place between 1 and 4 months aftersowing, depending on the climate and tree type. Once roots appearon the under sides of the pots it is time to prune, and this must thenbe done every 1 to 2 months depending on how quickly the rootsgrow. Check root length regularly and prune accordingly.


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20 cm

10 cm

20 cm

A: Pruning the primary root

B: Pruning secondary roots

Figure 20: Root pruning (From: ILO, 1989).

The roots of seedlings in pots can also be pruned by pulling a metalwire between the containers and the bed. Cut the tap roots off using

a sharp knife.In order to prevent the secondary roots of seedlings getting tangledup in seedlingbeds, it may be necessary to trim them. The distancebetween the plants will determine how frequently this needs doing.You need to dig to a maximum depth of 20 cm (See Figure 20B).

Pruning of shootsPruning usually only takes place when the plants have grown toolarge, either through bad planning or an unforeseen delay in the

planting season. With fast growers, such as eucalyptus, it is oftenworth trimming a long shoot down to 30 cm (twice pot height). Thisencourages even growth of both leaves and roots.

Damping off controlDamping off is a common and serious disease found in many nurser-ies. This fungus disease infects germinating seeds and youngseedlings. The stems break off at ground level or dry up. Often youcan see a slimy mass at the base of the stem. High humidity, wet soil,heavy soil, too much shade, too dense planting and too high humus

A B


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content can all cause fungus growth. You can prevent damping off bymaking sure the soil is well ventilated (e.g. by thinning out) and byensuring that conditions do not become too damp. If plants dobecome sick remove them at once from the nursery.

6.9 Selection of plant material and preparation for planting out

Selection of planting material for planting out takes place in the nursery.Selection is done in order to: Remove sick and damaged seedlings; Remove seedlings which are too small or have weak root develop-

ment; Divide selected seedlings into two or more quality classes to make

sure that material of the same size and appearance is plantedtogether. Planting material which looks good but is still small can beleft longer in the nursery.

The quality of planting material can be determined by looking at theroot:shoot ratio. Plants between 15 and 40 cm in length with a woodyroot collar have a better chance of survival than smaller plants. Withpotted plants the size of the container will determine the maximum

seedling size. Once the roots can no longer grow freely the plant willstop growing.

Before planting out the planting material should gradually receive lesswater and more sun. This is known as hardening off and is done to getplants used to the conditions where they will be planted out. You shouldgradually stop watering from about 5 to 6 weeks before the date youplan to plant out. Water the planting material thoroughly once more onthe day before planting out.

Bare-rooted planting material can be taken from the nursery in the formof ordinary seedlings or as severely pruned seedlings (stumps andstriplings). Seedlings which have not been pruned are less susceptibleto disease. On the other hand stumps and striplings are easier totransport and are less likely to be damaged during transport. Extremepruning is not very common and only done in large nurseries.Striplings are seedlings of broad-leaved trees, where only the top leaveshave been left in place. All side shoots have been trimmed. Stumps areseedlings where both root and shoots have been pruned severely.


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The top is usually cut back to a stump of 2 cm and the roots are cut to alength of 22 cm. This severe pruning prevents growth temporarily andmakes digging up easier. Stump making is most commonly done fortree types which quickly form a long tap root, such as teak, neem,breadfruit and jackfruit. Stumps are often used to stabilise slopes withloose soil.

Bare-rooted planting material is usually dug up by first loosening the soilusing a fork or spade, and then using a spade to lift up the root clump.The plants are then shaken gently to remove excess soil from the rootsand they are then packed in sacks, banana leaves, plastic bags withholes or tins for transport.


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7 WORK AT THE SOWING AND PLANTING SITE

The best period for both sowing and planting is after the first regular

rains. This period is often the busiest time on the farm, therefore it isvery important to be well prepared. The tools and means of transportyou need must be available at the right place and the right time. If youhave your labour and time schedule well worked out then digging up,transport and planting out can all be done in quick succession. Thequicker these steps take place the less chance there is of things goingwrong. You also need to think of activities such as fencing againstlivestock. This costs time and needs to be in place before planting out.

7.1 Site preparation

When carrying out natural regeneration or direct seeding it is best toprepare the soil at the planting site first. This can be done in a numberof ways:

Scarifying the soil

Scarifying the soil is done by gently loosening the uppermost layer ofsoil. By doing so you can reduce the competition from grass. It alsoimproves the uptake of water by the soil.If you are planning on carrying out natural regeneration then soilpreparation involves removing dead material on the ground andscarifying the soil a

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