WOLAITA SODO UNIVERSITY

COLLEGE OF AGRICULTURE
DEPARTMENT OF HORTICULTURE

Compiled Note for the Course Fruit crop production and management (Plsc3094)
Chapter I: Introduction

Definition of horticulture

'Horticulture is the growing of flowers, fruits and vegetables, and plants for ornament and fancy. Incident to the
growing of the plants are all the questions of plant-breeding, variation of plants under domestication, and the
bearings and applications of many biological and physical sciences. Primarily it is an art, but it is intimately
connected with science at every point.'

Horticulture is a part of agriculture; 'for agriculture, in its largest meaning, is the business of raising products from
the land. It is customary, however, to limit the word agriculture to the growing of grains, forage, bread-stuffs,
textiles, and the like, and to the raising of animals.'

Horticulture has four Divisions

The field of horticulture is divided into four major categories:

1. Pomology - fruit growing - includes the culture of all fruits and nuts. Grape cultivation, viticulture, is a
specialized branch of pomology.

2. Olericulture - vegetable growing - deals with the culture of non-woody (herbaceous) plants for food.

3. Floriculture - flower growing - deals primarily with the cultivation of herbaceous flowering plants and
houseplants.

4. Ornamental horticulture - covers the growth of trees and shrubs for use in landscape design, and often with the
design and maintenance of gardens, parks, and recreational areas.

Fruit crop production: - The amount of edible fruits produced per a given area and per a given time
The word ‘fruit’ can be variously defined, botanically; a fruit is the developed ovary of flower after fertilization has
taken place. Some fruits develop without fertilization and do not contain seeds. A fruit, in the horticultural sense, is
something, which is eaten fresh and out of hand. Thus, apples, oranges and fresh and bananas are fruits; plantain and
tomatoes are ‘fruit vegetables’; peanuts and coconut are ‘oil seed’. The cultivation of perennial plants for their
edible fruits which are consumed either fresh or processed.

A fruit tree is a tree bearing fruit- the structure formed by the ripened ovary of a flower containing one or more
seeds. However, because all trees of flowering plant produce fruit, the term in horticultural usage applies to trees
providing fruit as human food.
1.2 History of Fruit production
Before the beginning of a agriculture human beings were entirely depend on gatherings of wild fruits, root and
tubers, and hunting of animals. From this fact we can say that the utilization of fruits by human being is as old as the
existence of life on earth. Cultivation of fruits is known to have started with early cultivation before birth of Christ
(B.C).
For example
 Citrus – 3000 B.C in china
 Peach- 2000 B.C in Mesopotamia
 Apple- 3000 B.C in Mesopotamia and Egypt
 Grape- 4000 B.C in Mesopotamia
 Mango- 4000 B.C in India
According to the second accout of creation in the biblical book of Genesis, Adam was created from the dust of earth
and placed in the Garden of Eden: Eva, the first woman created from one of the Adam’s ribs. Tempted by Eva,
Adam ate the forbidden fruit of the tree of the knowledge of good and Evil, the original sin of human kind and the
two were expelled from paradise for their disobedience.

1.3 Importance of Fruit Production in Ethiopia

1. Nutritional/ food value
Fruits are eaten raw or cooked, dried or preserved. Carbohydrate includes starch and sugar, constitute the principal
nutritional material. Eg Banana and Plantain. Most fruits contain considerable amount of vitamin A and B eg.
Mango and papaya and some are primary source of vitamin C (Citrus fruits and strawberries). Vitamin content is
sharply reduced in stronger and shipping of fresh fruits, but maintained efficiently in frozen fruit. In general fruits
contain little protein or fat exceptions are avocado, nuts and olives, which contain large quantities of fats. Although
the edible portion of fruits has small ash (inorganic content) fruits supply and important part of the mineral matter
necessary in human diet.
1. Income source- Ethiopia produces a broad range of fruit including citrus, banana, mango, papaya,
Avocado, guavas, grapes pineapple, passion fruit, apples and strawberry generates income to producers.
Recently she is started producing of high quality strawberry and exports to world market.
2. Source of foreign currency- in 2003/04 over 40,000 tons of fruits were exported.
3. Import substitution- e.g. Apple and grape were imported from Kenya and Europe by currently we try to
produced in country such as in Chencha, Guder and Awash areas.
4. Employment opportunity – many private farms employee trained and untrained man power to their farms.
5. Raw material for industries – e.g. Grape for wine, orange for marmalades, squash, Jelly
6. Source of medicine- e.g. papaya and pectin from papaya (as meat tenderizer), malice acids, citric acids,
tartaric acid (from grape).
1.4 present status of fruit production in Ethiopia
In general the contribution of the natural to the natural is quit low, negligible however at present different kinds of
fruit crops are growing in different regions of the country even if no well established data about their types of
amount and production available.

 Except very few fruit crops most of them grow in a fragmented in a mixed manner. Individual farmers in
different region in the country are believed to own 8,500ha (citrus banana)
 Enterprises:- such as upper awash agro industry enterprise ( Tibila, Merti Jeju farm, Nura Era farm, and
Merti fruit and vegetable processing), Awara melka farm, Ethiopian development corporation (Zeway
Horticulture) development enterprise Alem Tena farm. Estimated to occupy slightly higher than 500ha.
 In these farms several citrus fruits including
Orange, lemon sour orange, mandarin, grape fruits pummel lime and other fruits like grape, vine
grape, avocado, and strawberry and passion fruits are growing.
Et- fruit: - the Ethiopian fruits and vegetables marketing enterprise was established in 1980. At present it sells 85%
of fruits that are produces in the different enterprise.

At present the production of horticultural crops is given due attention and is considered to be the dependable source
of food to us to come to food self- sufficiency and source of foreign exchange. Currently about 12,000 has of fruit
plants is served in the peasant and state farms.
1.4. Potential of fruit production in Ethiopia
1. The agro-ecological factor of the country give the chances of all year round production capability and agro-
climatic condition make it suitable for the production of a broad range of fruit.
Climate- temperature and fain full are suitable to grow tropical, sub-tropical and temperature fruits.
2. availability of market
 local market
 Export- large quantities of fruits are exported to Djibouti and processed forms to Yemen, Saudi
Arabia and other Middle East countries.
3. Availability of good soil condition
4. cheap labor source
5. Availability of large water source. The country has 122 billion cubic meter surface water 2.6 billion cubic
meter ground water, 12 river basins, 18 natural lakes including the rift valley lakes and a potential of 3.7
million hectares irrigable lang.
1.5. Prospects of fruit production in Ethiopia.
 People attitude to consumption (to consider fruits as one of nutrients contributor)
 Presence of better processing facility and presenting the processed fruits in different forms up to the
interest of the consumers.
 Better storing facility:- storing under ideal storage conditions deepening on the kind of fruits.
  Transportation facility;- presence of good roads and well established transportation facility including
air plan to Bering to the fruits to the consumer.
 Supported with intensive research to meet particularly the consumer interest.
 Advertisement: - to advertise the importance of fruits through media.
1.6 Problems/ constraints associated to fruit production in Ethiopia
1. Poor knowledge of the society about the food value of fruit in diet
2. Absence of improved painting material
3. Limited research activities and lack of sufficient skilled man power in the filed
4. Lack of appropriate post-harvest handling technology
5. Disease and insect pests
6. Poor infrastructure

1.6. Classifications of Fruits

1. Classification based on shading or non-shading nature
i. evergreen fruits/tropical- fruits that don’t shade their leaves. E.g. tropical fruits like citrus, mango,
avocado, papaya, and banana
ii. Deciduous fruits/ temperature fruits- fruits that shade their leaves under adverse condition (extremely
high and low To). E.g. Temperature fruits like peach, pear, plum and apple.
2. Classification abased on mode of fruit development
i. True fruits- are fruits develop from an ovary with out inclusion of associated parts. E.g. citrus, guava,
mango
ii. False fruits- fruits develop from and ovary and associated part of the flower (receptacle is included).
E.g. Strawberry
3. Classification based on the number of ovaries incorporated in the structure
i. simple fruits- fruits that develop from single ovary or a single ripened ovary from a single flower. E.g.
grape, mango, citrus
ii. Multiple or compound fruits- fruits that developed from as a result of many individual ovaries fused in
to a single structure born on a single stalk. E.g. Pineapple, mulberry jackfruit
iii. Aggregate fruits- developed from many ovaries on common receptacles. E.g., strawberry
4. Classification based on nature and structure of the ovary wall (per carp).
i. berry fruits- entire per carp is fleshy, although skin is sometimes tough; may be one or many seeded.
E.g. grape, papaya, pomegranate, guava, banana and avocado. (The banana fruit is a seedless, parthenocarpic berry
developing without pollination and fertilization. In the pomegranate, the edible part is the fleshy layer (aril) around
each seed.)
ii. Hesperidium- berry with a leathery rind and parchment- like partitions between sections; typical fruit of
the citrus family (Rutaceae). E.g. Orange, lemon, grapefruit tangelo and kumquat.
 iii. drupe fruits or stone fruits- fleshy fruit with had inner layer (endocarp or stone surrounding the seed.
E.g. Peach, plum, necrarine, apricot, cherry, olive, mango and almond.
iv. Pome fruits – ovary or core surrounded by edible, fleshy receptacle tissue (hypanthium’s or fleshy
floral tube) that is really not part of the pericarp. The actual ovary or core is usually not eaten, at least by most
humans. This is typical fruit of certain members of the rose family (Rosaceae), including apple, pear, quince and
loquat.
v. Nuts- a nut may be defined as a one-seeded fruit with a hard pericarp( rip ended ovary wall). E.g.
walnut, chestnut.
5. Classification based on level of maturity
i. climacteric fruit- those which need to be stored fro some time after detached from the mother to attain
an edible state. E.g. Avocado, banana, papaya, bullock’s heart
ii. Non- climacteric fruit- which attains edible state or which ripens while attached on the mother tree. E.g.
citrus, grape, strawberry, apple, peach
Chapter 2: Propagation of Fruits
Plant propagation is deal with the multiplication and production of plant using propagates that representing specific
genotypes. A propagule is any plant part used to produce a new plant or a population of plants. Propagules are done
sexually by seed or vegetativley by stems, bud and other plant parts. Propagules included seeds, cuttings, layers,
buds, scions, explants, specialized structure (bulb, tuber, and corm)
Sexual propagation
This involves the utilization of seeds. A seed is a living entity which serves as a bridge between generations of
plants. It is formed in the pestle of the flower and develops from the ovule following fertilization. As the fertilized
egg grows and develops, it becomes the embryo of the seed. The embryo is a compete plant in miniature, for it
consists of leaf, stem, and root premordia.
While propagation by seed you must consider the following:
1. cultivars, strains and hybrids should be clearly known
 Cultivar means groups of closely related plants of common origin that have similar characteristics.
 Strains are special types selected from cultivars considered to be superior in some way.
 Hybrids is the first generation progeny from a cross of different cultivars, straisn or inbreed lines
2. good seed should be used
Characteristics of good seed
 True to name- the plant produced is the correct cultivar
 True- to type the produced plant have the desire characteristics of the plant
 Disease free
 Clean
 Of good viability
 Graded to size
In most cased in Ethiopia, majority of fruit crops are grown from seeds.
Formation of fruit seed and embryo
The sexual cycle included the development of the male (pollen) and female (embryo sac) structure of the flower. In
this part of the cycle reduction division of chromosome occurs to produce the haploid (n) chromosome number.
Pollen grain and an eight-called embryo sac contain haploid male and female gametes, respectively. During
glowering pollen grain transferred from the anther to the stigma (pollination), where it germinates. A pollen true
grows down the style in to the ovary until it reaches the embryo sac with in the ovule. Two male gametes from the
pollen tube are discharged in to the embryo sac- one to unite with female gamete (fertilization) to produce the zygote
and another to unite with polar nuclei to produce the endosperm. This is termed double fertilization. With many
angiosperms, the zygote is diploid (2n) and divides to become the embryo; the endosperm is triploid (3n) and
develops in to nutritive tissue for the developing embryo. Both structures are enclosed within the nucleolus (inside
the ovule) that functions initially as a nurse tissue for the developing embryo and endosperm.
Polyembryony and apomixes
These two phenomena represent variation from the normal pattern of zygote formation and embryogenesis.
Although related they are not the same phenomenon. Ployembryon means that more than one embryo develops
within a single seed one being sexual, the reminder apomictic. Examples are citrus and mango.
Polyembroy may be a result of:
 Nuecellar embryony
 Spontaneous occurrence of more than one egg nucleus in the embryo sac
 Cleavage of pre-embryo during development
Apomixes- results from the production of an embryo that bypass the usual process of meiosis and/or fertilization
process. Apomixis embryos are arising from egg cell in the embryo sac or from nucleus and integument. Seedling
plant produces in this manner as apomictic. The genotypes the embryo and resulting. Plant will be the same as the
seed plant. Seed production is asexual. The most important use of apomitic seedling is for rootstock because of this
vigor, lack of viruses and uniformity. Apomixis is a process in which normal sexual process of zygote formation is
replaced by system doesn’t cell present within a reproductive structure. How differential apomixes from normal
seedling ? Apomictic seedlings are identical because they arise from the same genetic make up Zygotic embryos
differ from apomictic seedling either long or short or differs morphology.

Fruit is mature ovary in flowering plants together with all inseparable connected parts of the flower. In nature fruit is
morally produced only after fertilization of ovules has taken place but in many plants largely cultivated varieties
such as seedless citrus fruits grapes bananas and cucumbers fruit develop without fertilization a process known as
parthenocarpy. In either case, the maturation of the ovary results in the withering of stigmas and anthers and
enlargement of the ovary or ovaries ovules within fertilized ovaries develop to produce seeds.
 Purpose of sexual propagation
 To develop uniform rootstock- this is true if the planting materials are ployembryonic (nuclear embryony)
E.g most citrus and mango cultivars.
 Used to perpetuate fruits that may not be successfully established by any known vegetative mans. E.g
papaya.
Major Demerits of sexual propagation
Mostly the seeding plants are characterized
 Tall in growth difficult to manage
 Low yielder
 Heterozygous (genetically variable)
 Long Juvenile period- long time to bear fruits for example grape from seed needs 7-8 years but grape from
cutting (vegetative0 need 3 to 4 years.
 Susceptible to major pests and disease
 Difficulty of germination in some seeds
Merits
 High root-to-shoot ratio of the younger plant
 Disease free planting material
 Easy to operate or cheapest method
 As a result of hybridization, new variety can be developed hetrosis can be exploited
 Planting material (seed) can be stored for longer period of time.
Special (Operations) practices in sexual propagation
1. stratification
2. Scarification
3. Embryjo Culture
1. Stratification the seeds of most of woody plant have a rest (dormancy) period. For hastening of germination and
increasing uniformity of emergency, stratification is employed. It is method of holding dormant seeds under moist
condition. Or stratification is a method of handling seeds in which the imbibed seeds are subjected to a period of
chilling to after- ripen the embryo.
Procedure
 Placing the seed in a moist medium of sand peat or loam soil
 Holding at 10C of slightly above freezing
Time required for stratification is from 1 to 6 months depending on species. It is the stimulation of nature’s method
of breaking the rest period in seeds.
2. Scarification – is the breaking scarring or injuring the seeds coat to promote imbibitions and germination. E.g.
seed of peach and almond
 Can be dome by – the use of acids
- sandpaper/any rough surface
3. Embryo Culture- This is exiting the embryo from the seed and placing it on nutritional media to obtain seedlings
from otherwise non- germinable seeds
 When the developing embryo id taken from immature seeds sand placed on sutable culture media (can be
auxins, IAA, Cytokines, Morash Segous Media) done or in combination it by-pass the rest period.
2.2 Asexual or Vegetative propagation
Vegetative propagation is the regeneration of plants fruit crops in our case) from vegetative structures such as stem
leaves or roots. The Goal of vegetative propagation is to reproduce progeny plants identical in genotype to a single
source plant. The biological process is known as cloning and the resulting population of plants is clone,
There are several reasons why asexual propagation of plants is used for several plants (fruit).
1. To propagate seedless fruit crops. For example Banana, seedless grape, seedless orange, pineapple
2. To maintain true –to – type or genetic uniformity i.e Avoid hetrozygosity or maintain cultivars
3. Asexual propagation is faster shorten the juvenile period
4. May be more economical
5. For plants which produce seeds but germinate with difficulty
6. combing more than one genotype in to a single plant
Conditions for Vegetative propagation
Environmental conditions –As with sexual propagation vegetatively propagated plants require
A. Optimum conditions of temperature oxygen and moisture
B. Favorable medium for good root development and water absorption.
 The propagation media, weather it be peat, sand, soil or other material has an influence
on temperature moisture and oxygen. This in turn affect success of vegetative
propagation
2. Internal conditions
 Food supply Are important internal factors
 Rest Period Which determine success of
 Hormonal balance asexual propagation
 In some cases, they must be proper stage of maturity 9or development to be come reactivated for the
meristematic process of root and shoot production.
Characteristics of good planting material for vegetative propagation
1. it should be true – to- name (the produce should be the correct cultivar)
2. It should be true – to – type ( the produced plant should have the desire characteristic)
3. It should be pathogen free.
Methods/types of asexual propagation
1. Layering
2. Cutting
3. Budding
4. Grafting
 5. Micro propagation/ tissue culture techniques
6. By using specialized plant structures /Organs
 Stolons/runners e.g. straw berry
 Rhizomes/ sucker e.g. pineapple
 Corms e.g. banana
I. Layering
Stems that are still attached to their parent plant may form roots where they come in contact with a rooting medium.
This method of vegetative propagation is generally successful, because water stress is minimized and carbohydrate
and mineral nutrient levels are high. The development of roots on a stem while the stem is still attached to the parent
plant is called layering. A layer is the rooted stem following detachment (removal) from the parent plant.

 Some plants propagate naturally by layering, but sometimes plant propagators assist the process. Layering
is enhanced y wounding the stem where the roots are to form. The rooting medium should always provide
aeration and a constant supply of moisture.

Methods of layering
Tip layering:- a type of layering where the tip of the stem of certain plants placed in proper environment at proper
stage of maturity to produce both shoot and root. E.g. black raspberry.
Steps- place the tip in the soil at a depth of 2-5 cm. the tip is highly meristematic hence root and shoot develops. The
tip grows downward first bends sharply and grows up ward,. The re-curved tip becomes anew plant. Remove the tip
layer and plant it in late or early spring.

Simple layering:- This is bending an intact shoot to the ground to cause adventitious roots to form. While
performing this type of layering the under side of the bend branch must be wounded to encourage the development
of worked tissue for healing in a meristematic process.
During the rooting period, layers are covered with soil or other rooting medial not only to exclude light (blanching is
the covering of an intact stem after it has grown, and etiolation, which is the effect produced as the shoot elongates
in the absence of light) but to provide continuous moisture, allow for good aeration and help to insulate the layer
from extreme temperatures. E.g. dieffenbachia
Simple layering can be done in early using a dormant branch, or in late summer using a mature branch. Periodically
check for adequate moisture and for the formation of roots. It may take one or more seasons before the layer is ready
to be removed for transplanting.

Compound (serpentine) layering is similar to simple layering, but several layers can result from a single stem,
Bend the stem to the rooting medium a for simple layering, but alternately cover and expose sections of the stem.
Each section should have at least one bud exposed and one bud covered with soil. Wound the lower side of each
stem section to be covered. This method works well for plants producing vine-like growth such as grapes.

Trench layering :–placing a shoot in a shallow trench after scaring the under side of the branch and them covering
lightly with moist soil as a result more plants can be arise from each bud. The tip of the branch should be left
exposed so that the flow of water, nutrients and manufactured food will continue through the stem.
Advantage- large number of new plants can be propagated from a single branch E.g Grape, blackberry
Mound layering- is useful with heavy-stemmed, closely branched shrubs and rootstocks of tree fruits. Cut the plant
back to 1 inch above the soil surface in the dormant season. Dormant buds will produce new shoots in the spring.
Mound soil over the new shoots as they grow. Roots will develop at the bases of the young shoots. Remove the
layers in the dormant season. Mound layering works well on apple rootstocks.

Air layering:- Involves girdling or cutting the bark of the stem. Application of the root promoting materials such as
IBA ,to the exposed wound is also essential. Then mound should be covered with masses of moist forest soil and
them wrapping around with a polythene film to hold the medium in place and keep it moist. Roots grow in to the
medium and the stem is then cut and planted. This method is proved to be effective to propagate plants which have
got difficulty of being propagated by the usual sexual or asexual methods. Young plants of ½ 2cm diameter are most
desirable. E.G Rubber plant, fig, jack fruit.
II propagation by cutting
In propagation by cutting a portion of a stem, leaf, or root is cut from parent plant and placed under favorable
condition to form roots and shoots thus produce a new independent plant. Such new plants are identical with their
mother plant. To obtain cutting materials selected species will be established in nursery and from these cuttings are
taken whenever desired. Cutting are parts of plants that are cut and separated from the mother tree and brought to
form roots and /or shoots and eventually develop in to entire plants. The cuttings are then prepared by first removing
the leaves from the bottom 4-6 cm to avoid leaves rotting in the rooting medium and contaminating it and then dip in
to rooting hormone (Indole Butric Acid and Naphtali Acetic Acid).
The purposes of treating cuttings with auxin type of hormones are
To increase the % of cuttings that form roots
To hasten root initiation
To increase the number and quality of roots
To increase uniformity of roots
Plants whose cuttings root easily (herbaceous Plants) may not justify the additional expense and efforts of using
these materials. Best use of rooting hormone is rather with plants whose cuttings will root but with difficulty. In
addition to the natural auxin (endogenous hormones- indole Acetic Acid) that is produced by the plant (particularly
in the buds and young shoots) rooting co-factors are also essential for rooting. One of such rooting co-factor could
be absisic acid. It promotes root initiation by
 Antagonizing GA that at certain concentration inhibits root formation.
 Protecting the root inducing naturally occurring auxin (IAA0 from destruction by enzyme, Indole acetic
acid.
Types of cutting
 Stem cutting –more common than the rest
- hard wood cutting
- semi hard wood cutting
- Soft wood cutting
- Herbaceous cutting
  Leaf cutting
 Leaf bud cutting (single-eye or node cutting)
 Root cutting
 Stem cuttings are classified according to the age of the wood from which they are taken
Hardwood cutting
 Are taken from fully mature tissues
 Are often slow to grow. However, they are not sensitive to environmental condition unlike other types of
cuttings.
Softwood cuttings:
 Are taken from new growth
 They are succulent and sensitive to the environment, however they often root quickly.
Semi- hardwood cuttings:
 Are from wood that has started to mature and has some bark present. However, they do not have fully
developed bark, as do hard wood cuttings
 Are intermediate in environmental sensitivity and speed of rooting.
Many plants can be propagated by several different types of cutting with satisfactory results. The preferred type
depends on individual circumstances: the least expensive and easiest method is usually selected.

For easy –to – root wood perennial plants, hard wood stem cutting in an outdoor nursery are frequently used because
of the simplicity and low cost. For more tender herbaceous species, or for those more difficult to propagate, it is
necessary to resort to the more expensive and more elaborate facilities required for rooting the leafy types of cutting.
In today’s containerized nurseries, a larger portion of easy and difficult –to - root species are propagated with mist,
fog, or contact polyethylene sheet systems. Root cutting of some species are also satisfactory, but cutting material
may be difficult to obtain in large quantities.

Factors that affect regeneration of plants from cutting

1. Physiological condition of the stock plant
I. Water stress- cutting showed reduced rooting when the cuttings were taken from stock plants
having a water deficit.
II. Carbohydrate the nutrition of the stock plant can exert a strong influence on the development of
roots and shoots from cutting. This si associated with carbohydrate; nitrogen ratio. Cutting with
high carbohydrate but with low nitrogen produce many roots but feeble shoots and vise versa.
III. Girdling- is constricting the stem. This blocks the down ward translocation of carbohydrate
hormones and other possible root promoting factors and can result in an increase in root initiation.
2. Juvenility factor/ age of the plant- Cutting from plants at juvenile/young stage often form new roots much more
readily than those from plants in the matured stage. This rooting ability in relation to juvenility may be
 explained by the increased production of rooting inhibitors as the plant grows older, and also may be a result of
lowering phenolic compounds 9 rooting co-factors.

Softwood cuttings

Branch indicating places to select hardwood cuttings. (a) (b) (c) (d)
Four types of hardwood cuttings: a – c: Basal
cuttings (a: “mallet”, b: “heel”, c: “straight”); d:
Tip cutting
Figure 10. Types of stem cutting.
3. Type of wood
A. Terminalvs. Lateral- the lateral shoots root better than the terminal ones. This is because they have
high carbohydrate while the terminal ones have high nitrogen.
B. Flowering vs. vegetative- it has been consistently noted for both roots and stem cuttings of many
species that better regeneration takes palace when cuttings are taken before or after rather than during the
flowering period. This si because flowers are competitive sinks (they take manufactured food but do not
manufactured themselves). Therefore cuttings should always be thane from vegetative wood where there
is more carbohydrate and not from flowering wood.
4. Presence of virus- The presence of virus reduces the rooting ability of the cut. i.e. cutting from virus free
clones roots considerably better than those infected stock.

III Grafting
Grafting is the art of commenting two pieces of living plant tissue together in such a manner that they will unite and
subsequently grow and developed as one composite. In grafting a scion from the genotype is united with a stock
(root stock) from another plant. The stock is usually a seedling rarely a rooted cutting or a planted air- layered
branch. For a good result of grafting the root stock as well as the scion has to be in good conditions, and the two
parts should be compatible.

The best time of grafting is 1-2 months before leaf flushing when the scions have dormant vegetative buds, i.e. the
dry season just before the onset of the wet season: or in cool climates the cool season just before the onset of the
warm season (spring) At that time the buds are just about to sprout and the level of the plant hormone auxin is high.
Grafting can be dome in the nursery in which case the stock is growing in a container. For some species grafting can
take place under field conditions, provided the graft union is well protected after the grafting.

Figure 11. The scion and the rootstock.

The Root Stock
Rootstocks are usually grown from seeds. Good material should be used for root stock, i.e. plants with a well
developed root system and resistance to soil-borne diseases. The seedlings are kept in the nursery longer and are
grown to a bigger than normal planting size, since they have to fit with the scions. For most species the plants will
be about 50–70 cm high when grafting takes place. Therefore seedlings should be grown in relatively big pots, i.e. at
least 10–15 cm diameter, depending on species. The root stock is fit for grafting when the stem is about 0.6–1.2 cm
diameter at the upper third. The root stock should be tendered carefully before and after the grafting.

Figure 12. Rooted rootstock

The Scion
Conditions vary according to species. Following characteristics are guidelines:
• Scions should be taken from the upper part of the tree.
• Scions should be taken from vigorously growing branches.
• Scion length should be about 15–25 cm.
 • Scion diameter should be according to the size of the stock, i.e. 6–12 mm in diameter.
• Scions should be without flower buds.
• Scions should have well developed vegetative buds in a dormant stage.

The scions should be kept moist and cool until the grafting takes place. Grafting should be done as soon as possible
after collection. The two joined parts should have maximum cambial contact. If the root stock has a bigger diameter
than the scion, the joint should fit in one side only. A scion should never have larger diameter than root stock. An
example of a joint in splice grafting was the scion is considerably smaller than the stock is shown below.

Cross section of stem, showing Uneven joint correctly fit: The Uneven joint incorrectly fit:
cambium, bark, pith and wood. cambial layers at one side are joined The two parts will not “take”
in order to maximize cambial contact. since there is little or no
cambial contact.
Figure 11. cut and joint
When the two parts are brought together grafting tape or string is wrapped around the joint. The wrapping should be
tight and completely cover the joint. It serves 3 purposes-
- It keeps the two pars together in a fixed position until they have grown together.
- It restricts evaporation from the cut.
- It excludes water and air, and entry of fungi at the joint.
Methods of grafting
1. Whip Graft (Splice Graft)
The whip graft is used mostly on young apple and pear trees when the branches are relatively small (not more than
3.80 in diameter) and the under stock are about the same diameter as the scion of the new cultivar.
Cut- cut off a branch of the under stock, leaving a tub at least a foot long. Make a straight, slanting cut about 3.80
cm long on both the scion and the stock (see A and C figure 12). Make the cut straight and even- one stroke wit a
harp knife will do it. For the tongue, make a straight draw cut (not split), beginning near the top and cutting about
the full length of the level (B and D).
Figure 12.
The whip graft is usually used for grafting root stocks and section but can also be used for grafting small branches.
Union – match the two parts together (E). Unless the scion and stock are the same size, be sure the scion is in
contact with the inner bark on one side. If the toe of either the stock or scion extends beyond the heel of the other,
cut if off evenly.
Tying and covering- bind tightly with tape, and then carefully cover the union and binding material with grafting
compound.
This type of graft is difficult for the beginner but is used extensively by experienced operators. It lends it self to the
tape method of binding. Tape serves to seal the wound and bind the parts together. While other types of grafts
depend on the bark slipping well, the whip graft does not. In fact, it is best if you make this graft before the news
tongue of wood.
Aftercare- removes wrapping as soon as the scion has started to grow to prevent girdling of the tree.
2. Cleft Graft (split graft)
The cleft graft is used for top working older established apple and pear trees, either on the trunk of a mall tree or on
the side branches of a larger tree. It is best adapted to branches 2.50 to 5 cm in diameter. The grafts are made within
61 to 91 cm of the trunk or main branches and preferably not more than 122 to 183cm from ground, or new top of
tree will be too high.
Cuts- select a place free from knots and cut off the stock with a saw. Cut the cleft (avoid splitting if possible) with a
grafting chisel, large knife or hatchet. After a few trials you will learn the proper depth to cleft. In horizontal
branches, the cleft should be sidewise, that is, not perpendicular, to reduce breakage from birds and storms.
With a sloping cut about 1.5 cm above the upper bud, cut the scions to include three buds, and to a blunt wedge
about 3.80cm in length with one side slightly thicker than the other (see A and B in Figure 13). If the scion wedge is
cut to a sharp point there is danger of the bark peeling. Also a sharp scion wedge’ will not fit the cleft as well (C).
Figure 13. The cleft graft is the one to use on large branches

Union- open the cleft slightly with a grafting tool or screw driver. Insert a scion on each side, with the inner bark of
stock and scion in contact. Have the thick side of the scion out ward (B).
Keep in mind that the bark of the larger stock is thicker than the scion bark, so the scion should not be flush with the
stock. A very slight tilt will assure a contact, at least where the cambium layers cross (D).
Tying and covering- there is no need to tie, unless the stock is small and does not bind well. Cover the unions with
grafting compound and be sure the cleft is covered its full length (E).
Aftercare- scions that are growing vigorously will need attention to prevent breakage by birds, ice and storms.
Either tie the scion to a supporting brace (see B in Figure 13), or pinch back the tips before growth becomes
excessive. For additional support, circle all the shoots from one setup with twine (A).

3. The side graft

Although the side graft is adapted to a wide range of branch sizes (0.60 to 2cm diameter), its use is generally
restricted to branches that are too large for the whip graft yet not large enough for the cleft graft. As the name
suggest, the scion is inserted in to the side of the stock, which is generally larger in diameter than the scion.
Cuts- select a smooth place on the under stock branch at least a foot from the trunk. Make a slanting cut at a narrow
angle almost to the pith ( core of the branch)(see B in Figure 14). Cut the scion to a short sharp wedge (about 2.5
cm) with one side thicker than the other (see A).
Figure 14. In the side graft, the cut goes across the grain to reduce splitting.

Union – bend the branch slightly to open the cut. Press the scion in so the cambium layers of the stock and scion
meet at one side ©.
Tying and covering- tying is unnecessary if the stock binds well, but you may have to ties small materials if the
scion is not held firmly. Cut surfaces should then be covered with grafting compound (E).
Aftercare- in about two weeks cut off the stock above the union (D) using sharp shears in order to avoid disturbing
the scion. Then cover the cut surface with grafting compound (D).
If the graft has been tied, cut the banking shortly after growing starts; this will prevent girdling. In the first season,
you may allow some shoot growing from below the graft, but do not permit this growth to shade the scion growth.
After the first season, all growth should be cut off, except that of the graft.
Inspect grafts during the growing season to guard against faulty covering or binding. If shoots are attacked by fire
blight, cut them 15 cm below with visible symptoms.
IV .Budding
Budding is a form of grafting. However budding utilizes only one bud and a small section of bark with or without
wood. It is the principal means of propagating fruits like stone fruits (apple, pear, peach and plum). Citrus fruits,
Avocado and rose. It is accomplished when the rootstock is in active growth (during late summer) than in resting/
dormant stage so that the cambium divides and the bark separate readily from the wood. During late summer the
root stock plants are also large enough to accommodate the bud.
Requirements:
 Rootstock should have the desired characteristics of vigor, pauper growth habit, and resistance to soil born
pests as well as being easily propagated.
 Bark that slips on the stock plant/ active growth stage
 Buds that are resting/ dormant fro insertion
 Compatibility b/n the bud and the stock
Types of budding
1. T-bidding- this method is generally used during the growing season after buds have formed on current season’s
growth and whiel the bark is slipping.
Procedure:
A. Bud sticks are collected from current season’s growth from the cultivars to be budded
B. The leaf blades are removed.
C. The petiole is left attached for future use as “handles” for the buds.
D. The stock is prepared for insertion of the bud by making a T-cut in the bark.
E. The stock and the baud are wrapped and tied to avoid desiccation.
T- budding is used fro forest and fruit trees with a diameter of 6-25 mm and a relatively thin and flexible bark that
can easily be lifted. An inverted T-cut in the root stock is sometimes used in order to avoid water entrance. The bud
should then be prepared correspondingly with the straight cut at the proximal end.

2. Inverted T-budding- the principle is the same with shield budding except an inverted T-cut is made. In the rainy
localities, water running down the stem of the rootstock may enter the T-cut, soak under the bark of the rootstock
and prevent the shield piece from healing into place. Under such condition an inverted T-incision gives better result.

A T-formed cut is made in A slicing cut of the budstick is The bark of the T-formed cut in the
the root stock vertical about made from ca. 2.5 cm under the stock is opened. The shield is inserted
2.5 cm, horizontal about ⅓ of bud to 2 cm above. The shield is by pushing it downwards under the
circumference. cut free with a horizontal cut ≈2 two flaps of bark.
cm above the bud.

Figure: T-budding
3. Patch budding- A less common but often useful method of budding involves relocating a patch of bark which
contains the bud. It is wieldy and successfully used on thick bark species like nuts. It requires that the bark of both
the rootstock and the bud stick be slipping easily. The path bud must be precisely matched with the peeled area of
the stock, especially above and below the bud.

Two parallel horizontal cuts are The bud stick is cut similar to The bud patch is inserted into the
made on the root stock, about ⅓ of the root stock, horizontal with a patch hole in the root stock. The
the circumference using a double double bladed knife and vertical patch may need to be trimmed at
bladed knife. The two cuts are at each side. The bud is one side in order to make a tight fit.
connected at each side by vertical removed.
cuts and the patch is removed.
Used for forest and fruit trees with a relatively thick bark. The bud stick should not be larger than ≈25mm in
diameter while the root stock may be up to 10 cm thick. The bark should be approximately the same
thickness.

Figure Patch budding

4. Chip budding- chip budding is generally used with small materials. 13-25mm in diameter. The buds are
taken from matured canes, but the stocks should be in active growth condition during late summer or early fall. The
chips in both rootstock and bud sticks are cut out in the same manner. In the bud stick, the first cut is made just
below the bud and down in to the wood at an angle of 30-45 degree. The second cut is started about 25mm above the
bud and goes inward and downward behind the bud until it intersect the firs cut. The chip is removed from the
rootstock and replaced by the one from the bud stick.

Root stock: First cut is made at Budstick: Cut as for the root stock. First The bud is inserted in the root
an angle of 45° downwards, ¼ cut is made 6 mm below the bud. Second stock.
of the diameter. Second cut is
cut is made ≈ 13 mm above the bud
 made ≈ 25 mm above the first, going downwards to meet the first cut.
going downwards, to meet the The bud with attached wood is removed.
first cut.

Chip budding is used for small material 12–25 cm in diameter. Its main use is that it can be applied outside the
active growth season when the bark is not slipping.
Figure Chip budding

5. I-budding-in I-budding, the patch is cut in the form of a rectangular or a square, just as for patch budding.
With the same parallel- blade knife, two transverse cuts are made through the bark of the rootstock. These are
joined at their center by a single vertical cut. The two flaps of bark can then be raised to insert the bud patch
beneath them. I-budding is mot appropriate when the bark of the rootstock is match thicker than that of the
bud stick.

Two parallel cuts are made on The patch containing the bud is The two sides of the bark of the
the root stock using a double cut off by the help of the two I-formed cut are lifted and the
bladed knife. The middle of the bladed knife. bud patch is inserted.
two cuts is connected, using a
vertical cut
Modified patch budding used when the bark of the stock is considerably thicker than that of the budstick
Figure:- I-budding

V. Micro-propagation/tissue culture
Micro-propagation is the ability to establish and maintain plant organs (embryos, shoots, roots, flowers) and plant
tissue in aseptic culture and to generate new plants from them. The most exploited and popular method in tissue
culture is the true-to-type propagation of a genotype by in vetro techniques.
 In vetro-out side the living system
 In vivo-inside the living system
Advantage
 Fast and reliable
 Rapid and large number of material can be obtained
 Disease free planting material
 CHAPTER 3.
Nursery establishment and management
Nursery is the safest place were fruit seedlings are raised for further plating. A nursery site must be located with the
realization that a perfect site does not exist and that choice of site will require compromise. However, careful
attention to the selection of a permanent nursery site will amply repay all the effort expended.
The need for nursery establishment
1. to give seeds better condition for germination
2. to apply optimum growing conditions to the fruit plant during their very development stage
3. to economized on seeds
4. to avoid weak and diseased plants so as to obtain uniform seedlings
3.1 Nursery site selection
The area for nursery bed should be level, or nearly so. A slight slope (0.5% maximum) is beneficial for better
surface drainage, but slope greater than 5% can cause erosion, necessitating expensive control measure, and may
cause undesirable translocation of soluble fertilizer salts. Furthermore, all mechanical equipments used in fruit
nurseries operate best on level ground. This is the most important step in the whole nursery operation.
Factors to be considered
a. Slop(topography)- flat to gentle slop (0-5%)- for better management, the lower is the better
b. Structure and texture of the soil- sandy loam or loam sand with good drainage are excellent for nurseries
 Depth (at least 1m) should be free of hard pan
 pH 5-7
 Free drainage type
c. Frost free location or the site never be subject to forest.
d. Accessible- to permanent water supply, plantation site, roads and other infrastructures
e. Proximity to customers labor and services
f. The sit need to be protected from the prevailing wind
g. The site should be free from noxious weeds, diseases and insect pests.
3.2 Raising seedling in plastic tubes
This is done for fruit species that are difficult to establish when planted bare root
 If they are to be transplanted to distance place. Eg apple seedlings
 If they are of high value seed/ expensive.
Seedlings- plants rose from seeds and developed a strong tap root.
Rotted cutting- plants rose from cuttings and developed adventitious rots.
3.3 Land preparation
Purpose
To make the soil friable and clean
 Land clearing – removal of plant debris
 Plowing, disking and harrowing
  Amending with organic manure- FYM, compost and any other organic refuse.
 Seed bed preparation- in bed preparation the bed could be
 Raised
 Sunken } depending on the environmental condition
 Fiat
Bed size

1-1.5m

5-20m
Where width 1 to 1.5 m, it manageable size for cultural operation length could be al long as 20m or more.
Preparing pots/containers-could be polythene tube pot
The pot/container is field with forest soil which is good in nutrient, structure and texture
Planting/seed sowing
In nursery seeds are sown, cuttings and layers are made to initiate roots. During planting time planning the period of
dormancy has to be given due attention problems of dormancy can be tackled by
 Scarification
 Stratification } These can induce/facilitate germination
Depth of sowing
Determines the rate emergency and stand density
Factors to be considered
1. seed size
Large- Avocado, mango
Medium- e.g. Citrus, papaya} for all the depth of sowing can go 2-3 times the size of the seed
Small- e.g.. Grape, guava
2. condition of the seed bed
3. environment at the times of planting
4. type of germination
Spacing/density of plants
This depends on size of the seed. The spacing commonly used in tropical condition 30-50 x 5-20cm for plants to be
pricked out to permanent area bare root.
Pricking- is the transfer of seedlings from seedbed to plastic tubes so as to give a better growing condition.
3.4 Nursery Management
All routine activities from sawing to transplanting to the permanent place are included in the nursery management
practice.
 1. Thinning
Thinning is a cultural practice, which involves removal of surplus seedling from densely populated seedlings to
achieve desired planting density in nursery bed by retaining healthy and vigorous plants. Thinning carried out when
the plant are sufficiently developed.
2. Fertilization
Although every site has its fertility status and fruits have their own nutritional requirement. Major nutrient for
growth of fruit seedlings are NPK. As a rule, no fertilizer at planting time but it applied during soil preparation that
is done in fall before planting. After germination or rooting an observation on plants for deficiency symptom and
timely correction of the situation is vital.
3. Watering
Watering of seed bed is one of the cultural practices that should not be neglected at any time. Both under and over
water are harmful to the growth of seedlings. Seedling, which are water stressed are show stunted with poorly
developed root and shoot. They are less likely to establish well in the field. On the other hand excess watering of
seedling creates poor drainage and suffocation of roots and encourages the development of fungal disease such as
“damping-off”. Optimum moisture (water).
4. Pest Control
Insects, diseases and weeds will always exist in great abundance in the nursery. To control those pests we can use
the following pest control methods.
 Cultural control method
 Chemical control method
 Biological control method
 Mechanical control and
 With developing of integrated pest management (IPM)
5. Hardening and Preparing for Field Planting
Hardening-off is the process of preparing plants to stand with adverse condition in the field. Transplants are
hardened prior to placing in the field to reduce shock and stress due to the transplanting process. Plants are hardened
by acclimating them to the anticipated growing condition in the field. This is accomplished by slowly removing the
optimum showing conditions of the greenhouse by reducing the water, temperature, and/or fertilizer that the pants
receive.
Under out door conditions, where the regulation of temperature is hardly, the bets way to harden seedlings is by
gradual decrease in water supply. However, it is unnecessary to let the plans wilt suddenly rather light watering with
more days internal will safely serve the purpose.
Depending on the fruit type step by step removed from the seedbed to prepare the seedlings to withstand hot weather
and strong sunshine in the filed. Under temperature condition where the out door temperature could be very low
during winter season; Harding is accomplished by exposing the plants to temperatures lower than those used for
optimum growth.
Hardening-off will be much effective with combined applications of temperature and watering treatments. The
practice, which is intended to help the plant adapt the field condition, may be damaging if the treatment provided is
extended to over harden plants. Over hardening may slow down the recovery of plant, or even the yield of fruits.

Chapter 4: Planning and Establishing Orchards

Orchard is a long-term investment and needs lot of planning and expertise.

 While planning and planting a new orchard, one should give utmost attention and care to various
aspects like,
 Selection of location and site,
 Nature of soil and subs oil,
 Planning of suitable kinds and varieties of fruits,
 Proper planting distance and
 Purchasing of plants from reliable nurseries.

4.1.Preparation of land

 The land should be cleaned properly for free movement of men and machinery.
 All the trees, bushes and creepers should be removed.
 The soil of the area designed for growing fruit plants needs thorough preparation.
 A virgin land requires a deep ploughing and harrowing.
 The land should be repeatedly ploughed and bring the soil to a fine tilth.

4.1.1. Layout plan

 The marking of position of the plant in the field is referred as layout.

 The layout plan of the orchard should be prepared carefully, preferably in consultation with
horticultural experts.
 The orchard layout plan includes the system of planning provision for orchard paths, roads, water
channels and farm building.
 A sketch of the proposed orchard should be prepared before the actual planting is taken up

Aims:

1) To provide adequate space to plants.

2) To accommodate more number of plants.

3) Easy intercultural operations.

4) System of planting

The following are the important systems of planting generally followed on the basis of Agro-climatic
conditions to improve aesthetic view of the land.

1. SQUARE SYSTEM

It is the most commonly used method and easy to layout in the field. In this system, plant to plant and row to
row distance is the same. The plants are at the right angle to each other, every unit of four plants forming a square.
This system facilitates the intercultural in two directions after the orchard is planted.
Advantage:

1) Most easy and popular one.

2) In this row to row and plant to plant distance is kept similar.

3) Plants are exactly at right angle to each other.

4) Interculture operations can be done in both the directions.

5) Adequate space for inter-cultivation of remunerative crops like vegetables.

2. RECTANGULAR SYSTEM

In this system, the plot is divided into rectangles instead of squares and trees are planted at the four corners of the
rectangle in straight rows running at right angles. Like square system, this system also facilitates the interculture
in two directions. The only difference is that in this system more plants can be accommodated in the row keeping
more space between the rows.

Advantages:

1) Lay out in rectangular shape.

2) More space between row to row.

3) Inter-cultural operations can be done in both the ways.

4) Plants get proper space and sunlight.

1. HEXAGONAL SYSTEM/ Equilateral triangle

In hexagonal system, the trees are planted in the corners of equilateral triangles. Six trees thus form a hexagon
with another tree at its centre. This system, though a little difficult for execution but accommodates 15
percent more plants. Cultivation of land between the tree rows is possible in three directions with this
system. This system is generally followed where the land is costly and very fertile with ample provision of
irrigation water.

Advantages:

1) Accommodates 15 % more plants than the square system.

2) Plants are planted at the corner of equilateral triangle.

3) Six trees are planted making a hexagon.

4) The seventh tree is planted in the centre and called septule.

5) This requires fertile land.

Disadvantage: Lay out is difficult and cumbersome

2. QUINCUNX SYSTEM/ Diagonal system

This system is exactly like the square system but one additional tree is planted in the centre of each
square. The number of plants per acre by this system is almost doubled than the square system. Fruit trees
like papaya, kinnow, phalsa, guava, peach, plum etc. can be planted as fillers in the permanent trees
 provides an additional income to the grower in the early life of the orchard. The filler trees are uprooted when
the main orchard trees start commercial fruiting.

3. CONTOUR SYSTEM

This system is usually followed in the hilly areas with high slopes but it is very much similar to the
square/rectangular system. Under such circumstances, the trees may be well planted in lines following the
contour of the soil with only a slight slope. Irrigation and cultivation are then practiced only across the slope of
the land as this practice reduces the chances of soil erosion. In this system layout is done as in
square/rectangular system, first by establishing the base line at the lowest level and then marking for the trees
should be done from the base to the top. Bench terraces are used where the slope is greater than 10 per
cent.

4.2.SOIL AND ENVIRONMENT FOR HORTICCULTURE CROPS

SOIL:

 Soil is the upper most crust of earth surface which supports plant growth.
 It is defined as a three phase system in which plants grow. These phases are solid, liquid and gas and
are essential. Solid part is frame which provides space for other two. This consists of minerals, clay
minerals and organic matter.
 The soil is also a living system with millions of microbes that breakdown organic matter and builds it
again.
 Microbes are essential and survive only when soil is well aerated and rich in organic matter
and devoid of waterlogged conditions.
 Texture of soil depends on the size of solid particles and classified as gravel, coarse and fine sand,
silt and clay. classes.
 Likewise, arrangement of these particles is referred as structure, and both texture and structure lend
soil physical properties like water holding capacity, aeration and bulk density.
 Generally loamy soils and crumb structure are most preferred for fruit crops.
 According to level of organic matter, soils are classified as mineral soil or organic soil and
soil having more than 20% organic matter is organic soil like peat and muck.
 Minerals and salts lend chemical properties to the soil like pH, alkalinity, sodicity, salinity and cation
exchange capacity which influence the availability of nutrients in soil.
 Therefore, for making choice for soil, soil analysis in terms of following criteria is essential to decide
on land capability.
42.1. Criteria for land capability class:

i. Slope and erosion hazard.

ii. Soil depth.

iii. Drainage.

iv. Workability.

v. Stoniness and rockiness.

vi. Water holding capacity.

vii. Permeability.

viii. Nutrient availability.

ix. Fertility status.

x. Salinity, alkalinity and acidity hazards.

 Based on these criteria there are 8 capability classes, of which (i) to (iv) are suitable for cultivation and (v)
to (viii) are not suitable for cultivation.
 The soil provides support for the plant and act as storehouse of nutrients and water as well as oxygen for
root growth.
 The ability of the soil to support plant growth is often referred to as its productive capacity
which depends on fertility and physical condition. Therefore, the soil has to be a good soil.
 A good soil is one which has the capacity to nourish and sustain plant growth by providing mineral
particles (nutrients) in an available form to plants by their interaction with soil air, moisture,
microbes and humus.
 Generally a loam soil is considered to be a good soil.
 Generally fruit crops need porous, aerated, deep (2 m) uniformly textured soils and the pH of
soil should be within range of 6-8.

4.2.2. Planting Distance

To provide adequate space to the plant for normal development

 To permit

 proper intercultural operation

 easy passage of air and sunlight
 proper maintenance or orchard sanitation.
 Planting distance depends on
 nature of soil,
 type of plant (whether grafted or seedling)
 variety
4.2.3. Digging of Pits

 Before digging the pits, two outer pegs are fixed with the help of planting board.
 Already fixed peg is kept in the central notch to mark the right point to plant each tree.
 During digging of actual pit, the central peg is removed and two outer pegs remain undisturbed.
 These outer pegs help in locating the point where the plant is to be put in.
 Dig the pits 2-4 weeks in advance
 The ideal pit size would be 1X1X1m dimension.
 When the soil is fertile and does not have any type of hard pan, the size of pits may be of
50X50X50cm in dimension.

Filling of pits

 Keep the soil from upper half on one side and from lower half on other side.
 Allowed to weather for 2-4 weeks for disinfection by sunlight.
 Mix a mixture of

 well -decomposed FYM

 superphosphate (100 gm) and in upper as well as lower soil of the pit.
 Press the soil well to remove air pockets inside the pit.
 Upper level of pit is kept 15cm above from the field level.
 After filling, irrigate the pits to settle down the soil
Chapter 5: Management of Orchards

5.3. Water Requirements and Irrigation Methods For Horticulture Crops

Water is one of the most important inputs essential for the production of crops.

 Plants need it continuously during their life and in huge quantities.

 It profoundly influences photosynthesis, respiration, absorption, translocation and utilization of
mineral nutrients etc.
 Both its shortage and excess affects the growth and development of a plant directly and consequently its
yield and quality.

4.3.1. Soil needs the application of water to:

 Remove stress condition.

 Release nutrients in the soil solution for absorption by plants.
 Leach or wash out injurious salts from the soil.
 Preparation of land for raising crops.
 To maintain the temperature and humidity of the soil micro-climate and the activity of soil microbes at
optimum level.
 For the normal aeration and functioning of roots and shoots of the plants.
 Excess water needs to be removed for the normal aeration and functioning of roots and shoots of the plants
 Excess water creates unworkable soil condition.

IRRIGATION:

 It is defined as ―the artificial application of water to the plants in the event of shortage of
natural rains in order to obtain rapid growth and increased yields‖.
 It is an essential item in the cultivation of crops.
 Success in gardening depends on how efficiently irrigation is provided to gardens because
it is governed by many factors such as frequency, duration, intensity, source and method of
supply.

5.3.2.Factors affecting the supply of irrigation water to plants:

 Topography and soil characteristics.

 Kind of plant (root depth, water absorption capacity, growth habit, etc.).
 Weather condition.

When to irrigate?

 The time when a plant needs irrigation can only be judged by a keen observing eye.
 The plants need water when their new leaves begin to show a wilting appearance.
 A little before the trees show the sign of wilting.
 The shedding of broad leaves in orchard shows distress symptoms.
How much to irrigate?

 If water supply is limited, only a light irrigation can be given at a time with higher frequency of
irrigation.
 If water is available in plenty, the irrigation may be heavy with longer intervals between successive irrigations.
 However, inadequate irrigation reduces the growth and fruiting of the trees while, over irrigation
serves no useful purpose and it may even prove to be harmful.
 It may create water logging, the nutrients may get leached and fruits may become watery and develop poor
quality.
 Plants which have suffered from drought should not be given liberal doses of irrigations all at once. That may
result in the splitting of fruits and even the splitting of bark of the branches and trunk.

5.3.3.SYSTEMS OF IRRIGATIONS:

 Different systems of irrigation are followed in different parts of the country. The best system is the one
which meets the moisture seepage and evaporation.

Principally, irrigation systems can be divided under three broad headings:

I. Surface irrigation : a. Flooding b. Basin type c. Furrow type d. Ring type

II. Sub-surface irrigation: a. Trench method b. Through underground pipelines c. Perforated pipelines.

III. Overhead or aerial irrigation : a. Sprinkler . b. Revolving nozzles

IV. Drip or trickle irrigation

I. SURFACE IRRIGATION:

A. Flooding:

 When the land is flat, letting in water from one end floods the entire area.
 This system is commonly practiced in canal or tank bed areas.
 It is the easiest method and permits the use of bullock drawn implements in the orchards.
 But in this there is wastage of water and leads to soil erosion also.
 It encourages growth of weeds and spread of diseases like gummosis in citrus and collar root in papaya.

B. Basin system:

 In this system, circular basins are provided around the trunk of the tree.
 The basins are inter-connected in series and are fed through the main channel running perpendicular to
the tree rows.
 When compared to flooding, this system minimizes the loss of water.
 In this system of irrigation, the water close to trunk may bring about certain diseases like gummosis and
nutrients are likely to be carried over from one basin to the other.
C. Furrow system:

 Unlike the flood system, here the entire land surface is not covered with irrigation water.
 The furrows are opened in the entire orchard at 4‖ or less apart, depending upon the age of the trees.
 Water is let in these furrows from the main channels.
 In orchards, two furrows on each side of the rows are generally made.
 It is suited to such lands, which have a moderate slope to the extent of 1-2% if the water is to run freely and
reach the ends of the furrows.
 Where the slope is sharp, the furrows are made to follow the contour more or less closely.
 This method has disadvantage of excess of water penetration at the head than at the farther end, which
may result in variation in vigour and growth of trees.

D. Ring system:

 This is an improvement over the basin system.

 In this system, a ring is formed close and around the tree and water is let into the basin
 This method is recommended for citrus trees thereby reducing the chances of collar rot to which these trees
are often susceptible.
 The size of the ring will increase as the tree grows.
 In this system, the spread of diseases like collar rot, etc., are prevented.
 However, it involves more labour and capital and it does not permit uniform distribution of water throughout
the bed or basin as in the basin system of irrigation.

II. SUB-SURFACE IRRIGATION:

 This system consists of conducting water in number of furrows or ditches underground in

perforated pipelines until sufficient water is taken into the soil so as to retain the water table near the root
zone.
 In limited situation, this may be a very desirable system of irrigation.
 In general, however, it must be used with great caution because of the danger of water logging
and salt accumulation.
 If the sub-strata are so slowly permeable that practically no water moves through, water added may
stand in soil sufficiently for long time which results an injury to the plant root due to poor aeration.
 Where irrigation water or the sub-soil contains appreciable amount of salt, sub-soil irrigation is usually
not advisable.
 Land must be carefully leveled for successful subsoil irrigation so that raising the water table will wet all
parts of the field equally.

III. OVER HEAD OR AERIAL IRRIGATION:

 In this system, water is applied in the form of spring, somewhat resembling rainfall.
 This is accomplished by pumping water from original source into the main supply line from where it is
distributed to perforated pipes, which operate at low pressure (80 to 120 lb per square inch) and
supply the water in a fairly uniform rectangular pattern.
SPRINKLER IRRIGATION:

 May have definite economic advantages in developing new land that has never been irrigated,
particularly where the land is rough or the soil is too much porous, shallow or highly erodable.
 It is quite useful where only small streams are available, such as irrigation wells of small
capacity.
 It is helpful in irrigating at the seedling stage when the furrowing is difficult and flooding leads to
crusting of soil.
 Fertilizer materials may be evenly applied by this method.
 This is usually done by drawing liquid fertilizer solutions slowly into the pipe.

It has several disadvantages like

 High initial cost,

 Difficult to work in windy location,
 Trouble from clogging of nozzle,
 Interference in pollination process and
 Requirement of more labours while removing or resetting.

 In general, this system is best adopted for areas where ordinary surface systems are inefficient.

IV. DRIP OR TRICKLE SYSTEM:

 This is the most recent system of irrigating the plants.

 It is usually practise for high value crops, especially in green houses and glass houses.
 There will be an installation of pipelines with nozzles very close to the soil.
 The nozzle is fitted in such a way that water is dripped almost in the root-zone of the plants.
 Water is allowed to move in pipes under very low or no pressure and it drop at regular interval.
 This system of irrigation has advantages like no disturbance of the soil; soil moisture is
maintained, lesser leaching of nutrients from the soil.
 Drip irrigation system is the most recent usually practice for high value crops

5.4. NUTRIENT MANAGEMENT

The Nutrients are chemical elements which are absorbed by the plants in more or less quantity to transform
light energy into chemical energy and to keep up plant metabolism for the synthesis of organic materials .
These materials constitute among other things, foods for humans and animals and a range of raw materials for
various industrial uses. Feeding of plants with nutrients is termed as nutrition. Successful growth and
production of the plants in general requires a proper supply of the elements. These elements are regarded as
essential to life in higher plants.

Allen and Arnon (1955) laid out following criteria for categorising nutrients essentiality to plants:

1. Complete or partial lack of the element in question must make normal plant growth impossible

2. Deficiency symptoms must be reversibly by the addition of the elements in question

3. The element must play specific role in the plant metabolic symptom
They are:

1. Basic elements: Carbon (C),Hydrogen(H) and Oxygen( O) (03)

2. Macro elements : Nitrogen ( N), Phosphorus( P) Potash( K), Calcium( Ca) Magnesium (Mg) and
Sulphur(S) (06)

3. Micro elements : Manganese (Mn), Molybdenum ( Mo), Chlorine (Cl), Zinc ( Zn), Boron (B), Copper
(Cu) and Iron (Fe) (07)

Macro elements: The nutrients that are required in relatively large quantity are termed as macro elements.

Micro elements: are those required in relatively less quantity are termed as micro nutrients.

Besides some nutrients like Aluminium (Al), Cobalt (Co), Sodium (Na), Silica (Si) and Vanadium (V) are
not considered necessary always because either their essential character has been proved only in some plants or
in certain metabolic processes that are not always necessary.

Types Of Fertilizers

Inorganic fertilizers

 Industrially manufactured chemicals.

 Contains higher nutrient than organic manures.
 Nutrient input is lost through leaching, runoff, volatilization, fixation by soil or consumption by weeds etc.

Organic fertilizers

 These are plant and animal wastes that are used as nutrients after decomposition.
 Improves the soil tilth, aeration, water holding capacity and activity of micro-organism.

WHERE TO APPLY THE MANURES?

In fully grown trees, the manures and fertilizers should be given over the area, where their active roots are
spread. Fertilizer should be given in restricted area i.e., in the surrounding area of about 1 to 1.5 m away from
the trunk of the trees.

TIME OF FERTILIZER APPLICATION

 It must be applied when the plants need it.

 Timing depends on the type of fertilizer and climate.
 Fruit trees require more nutrients at the emergence of new flushes and differentiations of floral buds.
 Utilized more during the course of fruit development.
 Methods of fertilizer application:

1. Broadcasting:

 Fertilizer in solid state or granular or dust are spread uniformly over the entire field.
  Leaching loss may be more.

Disadvantages:

o Some of the elements like phosphorous and potash do not readily move in the soil. Therefore,
surface application may not be available to the trees especially in drier tracks.
o Leads to accumulation of potassium in surface soil beyond detrimental levels causing injury to
plants.
o Surface application always stimulates weed growth.

2. Band placement:

 Application of fertilizer on the sides of rows.

 Fertilizer in solid and liquid forms can be applied.
 Quantity of fertilizer may be economised.

3. RING PLACEMENT:

 Commonly followed in fruit trees.

 Fertilizers are applied in a ring encircling the trunk of the trees extending the entire canopy.
 It is more labour intensive and costly.

4. FOLIAR APPLICATION

 Fertilizers are applied in liquid form as foliar sprays.

 They are easily absorbed by leaves.
 Fertilizers are applied in a very low concentration tolerable to the leaves.
 Recommended when the nutrients are required in small quantity.

5. STARTER SOLUTION:

 Liquid form of fertilizer application.

 Seedlings and propagules are kept emerged up to their root system for varying duration in starter
solution.
 The starter solution is prepared either by dissolving concentrated fertilizer mixture at a concentration
not exceeding 1%.

4. FERTIGATION:

 Application of fertilizers in irrigation water in either open or closed systems.

 Nitrogen and sulphur are the principal nutrients applied.
 Phosphorous fertigation is less common because of formation of precipitates takes place with high Ca and
Mg containing water.
 Advantages :

o Nutrients especially nitrogen can be applied in several split doses at the time of greatest need of the plant.
o Nutrient is mixed with water and applied directly near the root zone, as such higher use efficiency.
o Cost on labour is saved.
Note: The grower must consider the economics and advantages before deciding for using fertigation.

Fertigation is used extensively in:

o Cut flower production in green houses.

o Fruit crops – Grapes, Papaya, Banana and Pomegranate.
o Vegetables- Tomato and Capscicum under poly/green houses.

TREE INJECTION:

 Direct injection of essential nutrients into the tree trunk.

 Iron salts are injected into chlorotic trees that are known to suffer from iron deficiency.

5.5. TRAINING AND PRUNING

Horticultural plants are grown for their produce like fruits, vegetable, flowers, medicinal components,
spices (oleoresins), aromatic (essential oils) etc. Therefore, these plants should be managed in such a way
that human desires for the purpose of growing them are fully satisfied in terms of quality and
quantity of produce. This demands direct manipulation of plant growth itself or plant environment
through various inputs. In manipulation of plant development, training and pruning are important for
which our knowledge about plant development and its phenology has to be complete. These practices are
important in fruit crops.

5.5.1. TRAINING:

Definition: Physical techniques that control the shape, size and direction of plant growth are known as
training or in other words training in effect is orientation of plant in space through techniques like tying,
fastening, staking, supporting over a trellis or pergola in a certain fashion or pruning of some parts.

Objectives:

 To improve appearance and usefulness of plant/tree through providing different shapes and securing
balanced distribution.
 To ease cultural practices including inter-cultivation, plant protection and harvesting.
 To improve performance like planting at an angle of 45° and horizontal orientation of branches make
them fruiting better.

Methods of Training : Method of training of a plant is determined by the nature of plant, climate,
purpose of growing, planting method, mechanization, etc. and therefore, intelligent choice is necessary.

Training of woody perennials: The woody perennials, which are widely spaced and remain on a
place for a long duration, are trained for develop strong framework for sustainable production of
quality produce and for ornamental beauty in different shapes (topiary). In these plants following types of
training are followed.

(i) Open centre system (Vase shaped):

o In this system the main stem is allowed to grow to a certain height and the leader is cut to
encourage lateral scaffold from near the ground giving a vase shaped plant.

This is common in peaches, apricots and ber (Fig.1).

(ii) Central leader system (closed centre):

In this system the central axis of plant is allowed to grow unhindered permitting branches all around.
This system is also known as closed centre system and common in use in apple, pear, mango and sapota
(Fig..2).

(iii) Modified leader system:

This system is in between open centre and central leader system wherein central axis is allowed to
grow unhindered up to 4-5 years and then the central stem is headed back and laterals are permitted. It is
common in apple, pear, cherry, plum, guava (Fig .3).

(iv) Cordon system :

 o This is a system wherein espalier is allowed with the help of training on wires. This system is
followed in vines incapable of standing on their stem. This can be trained in single cordon or
double cordon and commonly followed in crops like grape and passion fruit (Fig. .4).

(v) Training on pergola: To support perennial vine crops pergola is developed by a network of criss-
cross wires supported by RCC/angle iron poles on which vines are trained. This is common for crops like
grape, passion fruit, small gourd, pointed gourd and even peaches.

(vi) Training in different shapes:

o Generally ornamental bushes are trained in different shapes for the purpose of enhancing
beauty of places. These shapes could be vase, cone, cylindrical and rectangular box, flat and trapezoid.
Presently for the convenience of mechanization these shapes are being utilized in fruit trees.

4.5.2. Pruning

o Definition:
o It refers to removal of plant part like bud, shoot, root etc.. to strike a balance between
vegetative growth and production. This may also be done to adjust fruit load on the tree.

Objectives of pruning :

 To maintain the growth and vigour of the trees and to have a balance between the vegetative vigour
and fruitfulness, so as to be conductive for production of optimum crop of best quality.
 To shape the tree to make the best use of the space between trees while allowing the
necessary access.
 To regulate the size and quality of the fruits by way of proper distribution of the fruiting area.
 To regulate the succession of crop and to have the crop where it can be managed easily and cheaply.
 To spread the trees for economic orchard management.
 To remove the dead, diseased and over aged wood.
 For effective spraying of pesticides to the crop.
 Establishment of transplant where leaves/shoots are pruned to strike a balance between roots
and
 shoot so that plants lose less water against restricted root system lost during lifting of plants.
 Elimination of non-productive vegetative growth like water sprouts, suckers, dead and diseased
wood.
 In case of forest trees production of knot free timber.
 To minimize biannual bearing and consequent risk of die back.
 To get maximum plageiotrophic shoots/stems.


Types of pruning:

Basically there are three types of pruning with definite purposes.

(i) Frame pruning.

(ii) Maintenance pruning.

(iii) Renewal pruning.

1. Frame pruning: This pruning is done to provide shape and form to a plant in its formative years so that tree
develops strong framework and a shape for ease of operations. This process begins from nursery itself and
continues up to fruiting stage. This is done continuously irrespective of the season.

2. Maintenance pruning: To maintain status- in production level and for uniform performance this pruning is
done. In some plants like grapes, apple, pear, peach etc. (deciduous trees) it is an annual feature and in others
(evergreen like mango, sapota) it is rare confining to removal of water sprouts and unproductive growth and
opening of the tree.

3. Renewal pruning: This pruning is done in old trees like mangoes which shows decline. In this case severe
pruning is required.

Principles of pruning:

1. Excessive pruning should be avoided as it affects the growth of the plant by dwarfening and may
induce more of water suckers, fasciations (union of a number of parts side by side in a flat plane) and thus affect the
bearing potential.

2. In pruning, only that wood which is not necessary for the tree should be removed.

3. Pruning of larger limbs should be avoided as far as possible.

4. Pruning of young trees should be done more carefully than the yielding trees, since severe pruning of young trees
delays the cropping and much more of yield area will be removed than what is desired.

5.6. Pest Management

5.6.1. Weed management

It is difficult to define weed precisely, but one of the most useful is ‘a plant growing where it is not wanted’. In
general, any plant which is out of place is weed. Plants are classified as weeds because they compete for moisture,
soil nutrients, and light. It is quit possible for a plant to be considered a weed in one situation but a desirable plant in
another. Certain plants such as pig weed are essentially always weeds, but others such as Bermuda grass, which is a
very undesirable weed in a vegetable field, can be classified as a turf and pasture crops.
Damage from weeds: Weeds can cause damage in various ways, but the damage can be grouped in to the following
main categories:
1. Reduction in crop yield: because of their great number and rapid growth rate, weeds effectively compete with
crop plants for moisture, nutrient and light, causing costly direct damage in the form of reduced crop yields. A
troublesome feature of weeds is that they typically produce large numbers of seeds which remain viable for a long
time, making them very hard to eradicate. The general idea that one year of seeding is equal to seven years of
weeding, is true for most weeds.
2. Crop contamination: the leaves or seeds of weeds can contaminate food crops. Contamination is minimal with
tree fruits but is particularly serious in leafy vegetables. Contamination of grass seed with weed seeds can be
troublesome when grass is raised from seed.
3. Hosts for pests: weeds also harbor insect pests and disease causing organisms, encouraging their reproduction.
4. Poisonous weeds: sometimes poisonous species of weeds cause problems. With horticultural crops, poison can
cause serious discomfort to people who are allergic to it. Some species of mushrooms are also deadly poison.
5. Lack of aesthetic value: weeds are very undesirable from an aesthetic point of view because they detract from
the appearance of areas such as lawns, gardens, and golf courses. In addition, when weeds become larger they
interfere with gardening operations. With trees, sometimes climbing weeds shade the leaves and cause great
damage.
Types of weeds: weeds can be grouped into annuals, biennials, and perennials. Those which are very difficult to
control and are extremely serious pests are called noxious weeds.
i. Annual weeds: these weeds are propagated by seeds and can easily be controlled by cultivation and
specific herbicides during their early growth. They become more difficult to eliminate if permitted to seed.
They generally produce many seeds and unless controlled with disperse seeds many-fold for succeeding
seasons.
Examples: Avena fatue, Chenopodium album, Tribulus terrestris, Solanum nigrum, Datura stramonium, etc. are the
common ones in Ethiopia.
ii. Biennial weeds: these weeds grow for two seasons. They grow vegetatively the first season, and flower the
next season.
Examples: Lepidium virginucum, Stellaria media, Hordeum jubatum.
iii. Perennial weeds: they live for many years and are a serious problem for many horticultural crops,
especially perennials. Most perennial weeds can propagate themselves both by seed and vegetatively. They
are often deep rooted, very persistent, and able to withstand many efforts to eliminate them. In some cases
an entire crop season is lost reclaiming land infested by perennial weeds. Some of them become extremely
competitive even as individual plants.
Examples: Sorghum halepense, Cynodon dactylon, Cyperus rotundus.
Weed Control: Weeds can be controlled mechanically, competitive, biologically, and chemically. A combination of
one or more of these methods can often more effective than a single one in eradicating weeds in horticultural crops.
Mechanical: pulling by hand, hoeing, ploughing, and mowing are methods of mechanical weed controls. With
many crops, hoeing is the standard practice, but where possible it is being replaced by ploughing, either by draft
animals or recently with garden tractors. Mulches such as straw, sawdust, and dried sugar cane leaves not only
provide excellent weed control but offer other benefits such as stabilizing soil temperature and conserving moisture.
Black plastic sheets (polyethylene) are also very effective in weed control.
Competitive: this is the least expensive method of weed control, but it is only possible in a few circumstances. For
example, by maintaining a good stand of grass in a lawn, weed problems are reduced because the germinating weeds
are not able to compete with the established grass.
Biological: as the use of chemical pesticides is very controversial, suitable biological control is very much needed.
In some instances it has been found very successful. For example, prickly pear was a very serious weed problem in
Australia, but was controlled by the introduction of the Argentina moth. Great care must be taken that the insect or
the pathogen introduced will not harm desirable plants, animals or the environment.
Chemical: the most widely used technique of modern weed control involves chemicals called herbicides, or weed
killers. They may kill by contact or systemic action. Contact herbicides kill the tissue on contact, while systemic
herbicides, which are readily translocated, affect the entire plant. With small weeds the entire plant dies; with large
weeds, the foliage dies but the stem usually remains and new shoots may arise later from axillary buds. Discovery of
selective herbicides was a milestone because they can be applied in a mixed stand of plans and kill the undesirable
plants without harming the others.2, 4-D (dichlorophenoxyacetic acid) is the first of the growth-regulator type of
herbicides. It is not only effective at very low dosages but is selective and readily translocated within the plant.

5.7. Other pest management

Growers of fruit crops in Ethiopia generally have little knowledge of common diseases and insect pests. A grower
should keep a close eye on the health of his plants. He should be in regular touch with spraying and plant protection
programmes of the Agricultural Department. Sometimes the reason for the declining health of a crop is
misunderstood, and an insect attack is thought to be an elemental deficiency. If it is diagnosed correctly, the cause of
the decline can be overcome by controlling the insects. Insect and disease management programmes for various fruit
crops.
Chapter 6. Postharvest Handling of Horticultural crops
6.1. Introduction
 Post-harvest physiology: Deals with “The handling, storage, & marketing of perishable plants or plant
parts in the living state” (Kays, 1997).
 It deals with the time period from harvest or removal of the plant from its normal growing environment to the
time of ultimate utilization, deterioration or death.
 Ultimately maximum product quality is determined at harvest
 Postharvest physiology : is also called “the science of prolonging death”
 Characteristics of harvested plant products

 Products are alive!!

 They carryout respiration

 However , they no longer have access to

• Water

• light

• nutrition

 Furthermore, they are subjected to numerous stresses

– Wounding from being severed from plant

 – Mechanical damage (packing and transport)

– Low temperature

– Pathological stress

 Post-harvest losses

– Any change in the quantity or quality of a product after harvest that prevents or alters its intended use or
decreases its economic or nutritional value

– Estimated post-harvest losses(rough estimate 5-25% in developing

 Marketing and consumption trend

 Globalization

• Buyers are able to purchase whatever they want from any where in the world

• Provides opportunity for contra-seasonal trade between northern and southern hemispheres to
provide fresh produce to the market on a year round basis

• Inevitably reduce prices, thus enabling buyers to search the world for the cheapest and best quality
suppliers.

 Consumer demand

• Buyers expect suppliers to attain and maintain established standards of product quality, service, distribution
promotion and partnering.

• Supplier must be competitive even if offers a superior quality product or more reliable delivery

• Preferred suppliers are those who seek to identify better ways of servicing customer

6.2. Major Causes of Postharvest Losses

 Postharvest losses of horticultural commodities could be due to:

 mechanical injuries,

 metabolic stress, (transpiration, excess respiration and compositional change ),

 physiological disorders and/or

 due to microorganisms .

 Perishability varies from commodity to commodity and it is influenced by cultural practice and
environment under which they were produced as well as the way they are handled after
harvest.
 6.2.1. Pre-harvest factors
 Pre-harvest production practices may seriously affect post-harvest returns in quality and quantity.
 Some of them are:
1. Water supply (Irrigation):
 Pre-harvest production practices may seriously affect post-harvest returns in quality and quantity.
  Some of them are:
 Water supply (Irrigation):
 too much rain or irrigation: can lead to cracking of fruits (such as cherries, tomatoes) , excessive
turgidity leading to increased susceptibility to physical damage, reduced soluble solid content.
 lack of rain or irrigation: can lead to low juice content and thick skin in citrus fruit
 dry conditions followed by rain or irrigation: can give rise growth cracks (e. g in tomatoes )or
secondary growth (e.g. in potatoes).

2. Soil fertility, use of fertilizers

• lack of plant foods in the soil can seriously affect the quality of fresh produce at harvest.
• On the other hand, too much fertilizer can harm the dev’t and post-harvest condition of produce. Some of
the effects are:
– lack of nitrogen can lead to stunted growth or to the yellow-red discoloration of leaves in green
vegetables, e.g. cabbage;
– lack of potash can bring about poor fruit development and abnormal ripening
– calcium deficiency can cause blossom-end rot in tomatoes and bitter pit in apples

3. Cultivation practices: Good crop husbandry is important in achieving good yields and quality of fresh produce.
such as:
 weed control
 weeds are commonly alternate hosts for crop diseases and pests
 Weeds also compete with crops for nutrients and soil moisture
 crop hygiene -decaying plant residues, dead wood, and decaying fruit are all reservoirs of infection causing
post-harvest decay.
 Pruning – determine the crop load and fruit size – influence nutritional composition

4. Agricultural chemicals
• Pesticides and herbicides can damage produce

– by producing spray burns if used incorrectly, and

– they can leave poisonous residues on produce after harvest.

• Strict observance of the recommended delay between the last spraying and the harvesting is required.

• Growth-regulating chemicals – may influence nutritional composition indirectly due to delayed or

accelerated maturity

5. Maturity at harvest and harvesting method

o It is better to pick fruits mature but not ripe
o The incidence and severity of injuries are influenced by harvesting method and handling.

8.2.2. Mechanical damages

• Perishable crops are extremely susceptible to mechanical damage because of their high water content, size
and texture.

• Damage can greatly increase the rate of water loss, especially if it leads to breaks in the surface
layer & exposure of underlying tissue.

• In addition to this there are many effects of damages, these include:

 increased susceptibility of produce to microbial decay,

  increased the rate of respiration (heat production),

 evoking ethylene evolution as part of wound response,

 discoloration (external and internal) by decompartmentalizing cellular components (and

exposing them to oxygen).

Type of mechanical damage

Abrasions against rough surfaces
Compression: - occurs when the downward force on the crop is above a threshold level it
can be bruised eg. Over filling
Vibration:- -occurs when crops are being transported especially in lorries.

8.2.3. Metabolic stress or natural senescence

8.2.3.1. Transpiration/water loss/
Fruit and vegetables usually contain up to 95% water and their structure is therefore almost entirely
dependent on cell turgor.
Factors affecting the rate of water loss:
a/ Water vapor pressure deficit
 For any temperature and relative humidity, the water vapor pressure deficit is the amount of water vapor
needed to bring air to 100% relative humidity or it is the "dryness" of the air
 The rate at which water is lost from plant parts depends on the difference between the water vapor pressure
inside the plant and the pressure of water vapor in the air.
 To keep water loss from fresh produce as low as possible, it must be kept in a moist atmosphere.
 Equilibrium would be attained at anywhere between 97% and 100% relative humidity, depending on the
type of produce.

b/ Rate of air movement

 The faster the surrounding air moves over fresh produce the quicker water is lost.

 If the rate of air movement is low, then the humidity close to a commodity will tend to rise, thereby
slowing down the rate of water loss to some extent.

 During storage, some air movement through the produce is necessary (to remove heat of respiration) but
should be kept to the minimum necessary.

 Packaging of produce (e.g. perforated plastic bags) can be designed to achieve this.

c/ Atmosphere pressure
 Water evaporates more quickly at low atm pressures.

 Air freighted produce is therefore susceptible to wilting.

6.3.Harvesting and field handling

6.3.1.When is fresh produce to harvest?

Fruits harvested too early may lack flavor and may not ripen properly, while produce harvested too late may
be fibrous or have very limited market life .Similarly, vegetables are harvested over a wide range of
physiological stages, depending upon which part of the plant is used as food.

 When the crop is ready for harvest, labour and transport are available, and operations organized, the
decision as to when to start harvesting will depend largely on:
 weather conditions,
 the state of the market.
  The flexibility of the marketing date will depend on the crops.
 Some, such as root crops, can be harvested and sold over a long period,
 Others, such as soft berry fruits, must be marketed as soon as they are ready.
 Harvest during the coolest part of the day: early morning or late afternoon.
 Do not harvest produce when it is wet from dew or rain

 Physiological maturity

 It is the stage when Plant (part) is capable of further development or ripening when it is harvested.

• Examples of mature hort. / mature phys. crops: winter squash, melons, tomato, pepper and
eggplant

Horticultural maturity:
 It refers to the stage of development when plant and plant part possesses the pre-requisites for use by
consumers for a particular purpose.

• Examples of mature hort. / immature phys. crops: sweet corn, peas, snap beans, summer squash
and cucumber

6.3.2.Methods of harvesting
 The goals of harvesting are to gather a commodity from the field

 at the proper level of maturity,

 with a minimum damage and loss,
 as rapidly as possible, and
 at a minimum cost.
1. Hand Harvest
 Hand-harvesting is usual where the produce is at various stages of maturity within the crop
 Primary advantages
 Humans can accurately select for maturity
 Humans can handle fruit with a minimum of damage
 Hand harvest requires a minimum of capital investment
 The main problems with hand harvest
 Labor supply
 Labor strike during the harvest period
 increase in labor costs
2. Mechanical Harvest
 used with commodities which can be harvested at one time and are not sensitive to mechanical injury.
 Main advantages of mechanical equipment
 Potential of rapid harvest
 Improved conditions for workers
 Reduced problems associated with hand labor
 Mechanical harvest problems
 Rarely capable of selective harvest
 They tend to damage the commodity
 Damage to perennial crops (e.g. damage to bark)
 Lack of handling capacity, if not processed
 Social impacts of lower labor requirements
 They are expensive

 6.3. Temperature and humidity management

6.3.1.Temperature management

• Temperature is the most important environmental factor

• Tropical plants have evolved in warmer climates and therefore cannot tolerate low temperatures

• plants that have evolved in temperate, cooler climates that can be stored at 0°C.

• Keeping products at their lowest safe temperature increase storage life

– lowering respiration rate,

– slowing change in texture,

– reducing loss in vitamins (Vit C),

– decreasing sensitivity to ethylene and reducing water loss.

 Control of temperature related damages could be achieved

– product protection from sun heat (full sunlight),

– pre-cooling treatments to remove field heat,

– refrigeration and

– maintaining the cold chain from field until the end use

Pre-cooling
• When products are harvested, they usually have high field heat (often >10ºC ) than the
surrounding air.

• For highly perishable products field heat should be removed as quickly and economically as possible.

• The two main advantages of pre-cooling are

– the rapid cooling of the product and

– reduction in the required refrigeration capacity of the storage room

• Most storage rooms designed for refrigeration do not have the refrigeration capacity, or the air
movement needed for rapid cooling.

• Therefore, produce is usually cooled to its long-term storage temperature in special facilities
designed to rapidly remove produce heat.

• Pre-cooling can be done using several methods including

 ice,

 hydro- cooling,

 vacuum cooling

 and forced air cooling.

 The choice of cooling method depends largely on the commodity and the cost benefit associated with it.
 6.3.2. Relative humidity management

• Water loss through transpiration results in

– direct quantitative losses

– losses in appearance and textural quality

• Transpiration can be controlled either through

– direct application of postharvest treatments or

– manipulation of the environment (high RH)

• An appropriate RH range for storage of

– fruits is 85 to 95 %

– for most vegetables 90 to 98 %

– for dry onions and pumpkins is 70 to 75 %.

– Some root vegetables, such as carrot and radish, can best be held at 95 to 100 percent RH.

 Treatments that can be applied to minimize water loss in fruits and vegetables include:

– curing of certain root vegetables,

– waxing and the use of other coatings on commodities, such as apple, citrus fruits, peach, plum, and
tomato.

– packaging in polymeric films or adding polyethylene liners in packing

– providing moisture barriers that insulate walls of storage rooms and transit vehicles;

– regulating air movement and ventilation in relation to the produce load in the cold storage room.

6.4.. Postharvest Diseases of Horticultural Crops

Postharvest diseases refer to the decay, rotting and deterioration of fruit and Vegetable caused by
microorganisms. Loss of horticultural commodities by microorganisms can be rapid and Sever, particularly in
tropics where high temperature and high humidity favors rapid microbial growth. We can distinguish between
two types of losses due to postharvest diseases, namely qualitative losses and quantitative losses.
Quantitative losses simply refer to the quantity of the harvested produce that is decayed or rotten, may
be expressed as, for instance, weight lost per ton of produce.
• Qualitative losses from microbial attack take various forms.

• One is blemish or surface diseases which may lead to reduced market value (reduced consumer appeal even
if there might be little tissue destruction).

• Other forms of qualitative losses include reduced storage life due to accelerated ripening triggered
by few diseased fruits, changes in organoleptic properties.

– (e.g. off flavor in orange due to sour rot caused by Geotrichum).

• Often several forms of qualitative losses occur along with weight losses.