LECTURE 5
COFFEE
(COFFEA SPECIES)
Family: Rubiaceae
Cultivated varieties
 Varieties of cultivated coffee:
 Coffea arabica
 C. canephora (robusta coffee)
 C. liberica
 C. congoensis (tolerates temporary water logging)
 C. arabusta (C. arabica x C. canephora)
 C. abeokutae
 C. excelsa
 C. macrocarpa
 C. stenophylla
 C. brevipe
 Today the C. arabica and C. canephora are the most economic
and widely cultivated world-wide.
ORIGIN OF COFFEE
 Originated from Africa:
 C. arabica, despite its name, comes from Ethiopia. Its wild
population is still found in the undergrowth of high Abyssinian
plateaux.
 Wild populations of C. Canephora still exist in the evergreen
forests from central Africa to West Africa.
 C. liberica do exist with the C. canephora but more in Liberia than
other regions.
 C. Abeokutae species peculiarly found in Abeokuta, South West
Nigeria.
 Domestically in Abyssinian plateau, (1)“Abyssinian bun” is
traditionally made from dried coffee beans and butter (2) infusion
of the roasted and ground bean in boiling water.
Current distribution of cultivated coffee species
 Horticultural Science and Plant Breeding modified the cultivated species of
coffee to thrive in marginal ecological conditions by:
 Selection of varieties resistant to drought, temperature extremes, water logging,
disease and insect attacks,
 Selection of highly productive species of coffee stable in a number of environments
with excellent organoleptic properties.
 C. arabica: (Highland Coffee) South and Central America, Caribbean, India,
Pacific Islands, Indonesia, Viet Nam, New Guinea, Philippines, Highland
regions of Africa; Ethiopia, Kenya, Tanzania, Rwanda, Zimbabwe, Burundi,
Zaire, Angola, Cameroon, Guinea and Nigeria.
 C. canephora: (Lowland Coffee) Africa (relatively low quantity, hot and
humid areas), Uganda, Tanzania, Angola, Sudan, Zaire, Central African
Republic, Cameroon, Gabon, Benin, Togo, Ghana, Ivory Coast, Guinea, Sierra
Leone, Nigeria, India, Indonesia, New Caledonia, the Philippines, Viet Nam,
Cambodia, Brazil, Bolivia and Trinidad.
Ecology and Botany of cultivated coffee
 C. arabica:
 Original source of coffee beans and has best coffee quality.
 Most suitable climate is the original (Ethiopian) climate i.e. tropical climate
tempered with altitude with two contrasting seasons.
 Rainfall of between 750 mm and 3000 mm with 4 months of dry season.
 Average annual temperature of between 180C and 220C.
 C. arabica thrives in some lowland climates especially hot and humid equatorial
areas but altitude must be higher than 800 m asl for good berry yield.
 It is damaged by frosts in lowland and extreme cold in very high altitude.
 It has a slender tree which is heavily branched and kept in shape by judicious
pruning
 Axillary and sub-axillary buds develop into reproductive lateral branches.
 C. canephora:
 It is a lowland coffee originated from equatorial Africa.
 With the exception of C. arabica, all other species of coffee are lowland types.
 All lowland coffee types are similar in vegetative and reproductive
characteristics.
 Require hot and humid equatorial to sub-equatorial climates.
 Heavy annual rainfall of 1500 mm and 2500 mm spreading over 9 to 10 months
with high relative humidity and short dry season.
 Sandy and shallow soils are unsuitable. Coffee thrives on hillsides with gentle
slope and deep fertile soils.
 Temperature of between 270C and 300C.
 C. canephora is next to C. arabica in bean quality while C. Liberia and other
species are of lower bean quality.
Site Selection For Coffee Growing
 Site to be selected for coffee cultivation is determined by type
of coffee to be grown which is on the basis of requirements
for altitudes.
 Highland coffee – C. arabica requires 600 m asl and above.
 Medium altitude coffee – C. liberica requires 450 – 600 m asl.
 Lowland coffee – C. canephora requires 0 – 750 m asl.
 Deep, slightly acid, well-drained loams, (especially, hillsides
with a gentle slope) that are rich in nutrients especially
potash and organic matter are ideal for coffee.
Propagation of Coffee
 Raising of coffee seedlings:
 Plantable seeds or seedlings must be obtained from designated centers
– Research Institutes or Colleges and Faculties of Agriculture of
Universities.
 Never you obtain propagules from friends’ coffee farms.
 Preparation of coffee seeds –
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Pick ripe and healthy fruits that drop on the ground.
Depulp the fruits
Short-ferment coffee seeds for 24 hours.
Rub inside water to remove any traces of pulp still adhering to the seeds.
Air-dry the seeds in a well-ventilated area.
Moisture content must not be lower than 10% lest viability will be seriously
impaired.
 Sorting of seeds against small, abnormally-shaped, infected and infested
seeds.
 Selected seeds are ready for raising seedlings.
 If coffee seeds are to be stored / transported, treat with charcoal dust and
fungicides (especially copper-based fungicides) and aldrin dust against
termites.
Raising coffee seedlings contd.
 Seedlings are raised in a shaded nursery in a polythene (seedling)
bags filled with about 3 kg fertile top soil.
 Maintenance of seedlings in the nursery:
 Watering: Adequate watering is a must, even in the rainy season,
especially, if there are 5 consecutive days of no rain.
 Weeding: Manual weeding is encouraged. Though, chemical
weeding saves about 20 mandays but, not encouraged.
 Control of disease infection especially damping-off, leaf spot
(Cercospora spp.)
 Control of insect infestation especially mole crickets, larvae and
grubs, stem borers, defoliating caterpillars (Epiplema spp.) and
termites.
 If necessary, fertilizer may be applied by foliar application.
 C. canephora stays in the nursery for about 4 – 6 months while C.
arabica stays for up to 1 year.
 Towards the end of the nursery period, hardening must be carried
out.
Clonal / Vegetative Propagation of Coffee
 Multiplication of coffee plants by vegetative means (mainly cuttings)
enables total reproduction of all the traits of a selected individual plant, for
instance production capacity, reaction to environment (soil, climate
tolerance / resistance to pest attacks), technological and organoleptic
properties of coffee.
 Clonal propagation involves the use of stem cuttings, budwood, scion wood
for grafting and layering, taken from selected trees.
 Such trees are normally grown for the purpose of cloning.
 A coffee plantation grown from such special trees are made up of clones.
 Clonal mixtures is preferable in coffee plantation especially where selfsterile types like C. robusta is cloned.
 Earlier maturity and considerable increase in yield is achieved from clonallypropagated plants when compared to seedlings.
Propagation Of Coffee By Stem Cuttings
 Most commonly used form of vegetative propagation on an industrial scale.
 Internodes of orthotropic suckers are taken from selected clones and
rooted in special nurseries (humidified areas of a general nursery).
 Orthotropic stem cuttings grow into a well shaped coffee plant.
 Plagiotropic stem cuttings only grow horizontally into coffee bushes.
 The internodal sections in the cutting prepared develop their roots in a
porous substrate inside a propagator.
 The rooted cuttings are planted out in seedlings’ bags, hardened-off under
a shade in an humid environment.
 The successfully hardened clones are transplanted into the field after 6 – 8
months in the nursery.
Propagation Of Coffee By Stem Cuttings Contd.
 Selection and preparation of stem cuttings:
 Only semi-hard wood portion of the stem is used.
 With a grafting / budding knife, cut off the tip of the selected
orthotropic branches 15 days before cuttings are taken.
 The branches are cut into short segment of 7 – 10 cm in length,
consisting of 1 node and 2 leaves which are also cut into half or onethird.
 Cutting of the leaves may be in different shapes in order to differentiate
among various C. canephora clones.
 The upper portion of the cutting must be cut as close as possible to the
axils of the leaves in order to check growth of extra-axillary buds.
 The cuttings may be cleaved, if the diameter is sufficiently large.
Propagation Of Coffee By Stem Cuttings Contd.
Setting Of Cuttings:
Vertically insert prepared cuttings of coffee, in rows into
the previously moistened medium at a depth at which
the leaf just touches the medium (sawdust).
This arrangement is essential in order to avoid leaf drop,
which is indication that the cutting has not rooted.
Cutting planted at a planting density of 400 – 500
cuttings per square meter.
A full compartment is covered with transparent
polythene sheet and sprayed with water.
Propagation Of Coffee By Stem Cuttings Contd.
 Maintenance of set cuttings:
 Every morning, the chamber is sprayed with mist of water until microdroplets of the sprays become deposited on the leaves. A second spray
is carried out in the afternoon during the dry season.
 Mist-blowing of water is not only to keep the chamber humidified, but
also to keep the temperature stabilized at 250C – 300C.
 After 20 days of setting, callus would have developed and the first root
would have appeared.
 Transplanting of cuttings into the nursery begins at 6 weeks and
continues till 3 months.
 Any unrooted cuttings is discarded and propagator prepared for another
batch of cuttings.
 The success rate depends on physiological conditions of the prepared
cuttings.
 Transplanting and Hardening-off
 Coffee seedlings are maintained and hardened-off following the
standard operational procedures in the nursery.
 Transplanting Of Coffee Seedlings Into The Field:
Planting spacing / planting densities:
 C. canephora:
 4.0 m x 2.5 m (1100 trees/ha)
 2.5 m x 2.0 m (2000 trees/ha)
 C. arabica:
 4.0 m x 2.5 m (1000 trees/ha)
 2.0 m x 2.0 m (2500 trees/ha)
High density planting for Coffea spp, of > 5000 plants/ha, requires
a considerable investment in terms of fertilizers, plant treatments
and strict application of carefully planned procedures. It is
therefore practised in large plantations.
Maintenance Of Coffee Plantation
 Weeding: Clean-weeding during the establishment phase of the
transplants, especially, in the first 18 – 24 months eliminates weed
problems and thus facilitates good establishment of the
transplants.
 In a non-organic coffee production system, herbicides may be used to
check weed growth.
 Mulching: organic mulch is preferable. A gap of about 10 – 15 cm
radius should be left around a coffee plant unmulched in order to
reduce the risk of termite attacks.
 In a termite-infested land, the mulch should be sprayed with a
termiticide.
 Shade: shade requirement in coffee cultivation is controversial.
Research reports have indicated that coffee transplanted under
50% shade had better growth performance.
Maintenance Of Coffee Plantation Contd.
 Pruning:
 An important maintenance operation in coffee.
 Coffee yield is directly dependent on good pruning operations.
 Pruning in coffee is based on the understanding of the growth
habit of the crop plant which is of 2 types:
 Orthotropic growth, made up of vegetative verticals.
 Plagiotropic growth, made up of lateral or fruit (reproductive) branches.
 Pruning in coffee is complicated because it differs from place to
place.
 The basic principle of pruning in coffee culture is regeneration /
renovation of coffee trees in an orchard.
Forms Of Pruning In Coffee Culture
 De-suckering: Removal of unwanted suckers from coffee plants. It helps to
maintain required number of vertical stems.
 Topping: Simplest forms of pruning in coffee. It involves cutting off the
upper part of a developed, well-grown, vigorous coffee plant. topping
enables both vertical and lateral shoots to thicken. It induces heavy tillering,
especially, in C. canephora.
 Single stem: Only the most vigorous vertical stem is left upright to bear the
laterals on which berries are borne, while all other laterals are removed.
 Double stem rotation: Leaning / modified single stem / bayonet system.
This is applied when coffee plant, in fertile soil, grows luxuriantly. Two out
of a number of new shoots, after topping, are retained. One grows vertically
while the second is topped in order to induce fruit laterals. When vertical
bayonet fruits and bend over, a new vertical is initiated from the second
bayonet that was formally topped.
Forms Of Pruning In Coffee Culture Contd.
 Vertical / Upright multiple stem: After the first crop of coffee, 2 or
3 vertical stems are allowed to develop from the base, these are
topped at an height of about 1.8 m. The strongest, oldest and
healthiest among them is allowed to bear berries for the year
while the other shoots are suppressed by pruning or trimming.
The selected vertical is allowed to bear berries for 2 years before it
is cut and replaced with the next strongest shoot.
 Leaning multiple stem: This is recommended for areas with fairly
high temperature, good soil fertility, adequate rainfall and shade
provision. It involves topping coffee seedlings at about 0.5 m, new
shoots to become vertical are encouraged from the base, about 1
shoot per year. Terminal growth is unrestricted. During growth and
fruiting, farm workers go round the plantation to gently pull the
tops of fruit-bearing verticals outwards and downwards to fit them
for harvesting. Remove emerging suckers/shoots. The vertical can
remain productive for 5 years, if well-managed.
Forms Of Pruning In Coffee Culture Contd.
 Hawaiian system: This is an intensive upright / vertical stem rotation
system. It involves 4 – 6 verticals half of which are in heavy production each
year while the second half is held to light fruiting or prepared for next berry
production.
 Colombian system: Otherwise called umbrella system is normally applied to
coffee grown under shade. The verticals of young coffee plant are allowed
to grow to about 2 m and then topped. Growth from terminal 2 axils
prevented. Laterals allowed to grow horizontally branching repeatedly
which later bends downwards under the weight of the berries, to form a
dome-shaped / umbrella-like shape.
 Candelabra system: A Costa Rica system and it starts from the nursery
where the seedling is topped at about 30 cm. The topped seedlings, after
transplanted are topped again at 60 cm and thereafter, 2 equal verticals are
allowed to grow. These grow to about 1 m and are topped again. At this
stage, 4 verticals emerge and laterals encouraged to emerge for fruiting.
Laterals continue to bear berries for about 5 years before they are cut back
to 20 – 30 cm and new suckers allowed to emerge.
Forms Of Pruning In Coffee Culture Contd.
• Guatemalan system:
This is a form of soil-layering where the daughter coffee plant
becomes severed from the mother plant and thus becomes an
individual plant. This system exploits the easy-to-root ability of
coffee stems. Coffee seedlings, when transplanted into the field,
are bent down to an angle of 450 or an acute angle to the soil. This
inhibits top growth, but induces shoots to emerge from the base
of the seedling. Three to four verticals are allowed to grow and
the strongest are selected while the oldest stem is topped. The
succeeding multiple shoots are bent again to continue the system.
The vertical shoots put out laterals for berry production.
Harvesting And Processing Of Coffee Berry
 Harvesting:
 The earliness of bearing in coffee depends on variety, suitability of
the environment and adequate management.
 Generally coffee plants come into bearing 3 years after
transplanting into the field.
 The immature berries are green while the mature ones are either
yellow, purple or red depending on variety.
 Harvesting must be carried out when berries are ripe.
 Harvesting is carried out by hand because berries occur in clusters
and do not ripen at once.
 Harvesting is therefore an activity for the women and children.
Processing / Post-harvest Handling Of Coffee Berries.
 Wet method:
 Pick berries when ripe and depulp immediately in order to allow for
heating through fermentation which spoils the bean flavour.
 Soak in tanks full of water to eliminate infested berries and foreign
matter
 The good and fully mature berries are then fed into a pulping machine.
 Pulp being removed, coffee beans coated with mucilaginous covering
are transferred into a fermentation chamber for fermentation to
proceed for few hours.
 Alternatively, the mucilaginous beans are washed with water, under
pressure, to remove the mucilage, thus rendering fermentation
unnecessary.
 Coffee beans are then dried and are thus ready for market.
 Beans are of very high cup quality, but expensive and need skilled staff.
Processing / Post-harvest Handling Of Coffee Berries contd.
 Dry method:
 Coffee berries are spread out inside sun until they are completely
dried.
 The beans are then hulled (removal of pericarp) either with
machine or with a pestle and mortar.
 The pericarp chaff is removed by winnowing followed by picking.
 Proper drying eases hulling and winnowing.
 Dry method is simple with low capital cost per unit and does not
require skilled personnel.
 However, the long period needed for proper drying depends on
weather condition. Besides, the bean is of low quality and there is
wide fluctuations in bean quality among growers
Processing / Post-harvest Handling Of Coffee Berries contd.
 Grading:
 Re-drying – for uniform moisture content.
 Cleaning – removal of foreign matter and unhulled beans.
 Hulling and polishing – removal of testa.
 Size grading – a set of cylindrical sieve used to separate smaller and
broken beans.
 Density separation – removal of light black and defective beans.
 Hand-sorting – removal of defective beans which machine could not
remove.
 Mixing – proportional mixing of clean size-graded beans.
 Bagging – sewing up of mixed lots of specific weights for roasting.
Processing / Post-harvest Handling Of Coffee Berries contd.
Roasting:
Roasting brings out the proper flavour of coffee.
Roasting is normally carried out for 20 – 30 minutes.
Grinding:
Roasted coffee is ground into small particles before it
can be used.
Soluble coffees like Nescafe, are made from infusion of
coffee from roasted and ground beans which is
drastically dried in very hot air.
Major Diseases Of Coffee
Hemileia leaf rust: (the leaf)
Causal organisms: Hemileia vastatrix, H. coffeicola.
Control: use of resistant varieties, copper fungicides and
farm hygiene / sanitation.
American leaf spot: (foliage and berry)
Causal organisms: Stilbellum flavidum, Agaricus citricolor
Control: farm hygiene / sanitation, copper fungicides.
Black rot: (foliage and berry)
Causal organism: Pellicularia koleroga
Control: farm sanitation, copper fungicides.
Major Insect Pest Of Coffee
Defoliator (Epicampoptera glauca).
Effect: coffee plant with lace-like leaves
Control: spray plant with endosulfan directing jet upwards
from underneath.
Berry borers (Stephanoderes hampei).
Effect: Beetles bore small holes in ends of berries. Larvae
feed, develop and destroy berries.
Control: Regular harvesting, hygienic measures, spray with
insecticides.
Termites.
Effect: roots eaten up .Coffee plant falls off without any
symptom.
Control: Destroy termitarium in and around coffee plots.