Coffee
Family - Rubiaceae
Genus - Coffea
Species - arabica and canephora
Two Types of Coffee
About 90 Coffea spp in Africa



Arabica, C. arabica
Tetraploid, self fertile
Ethiopia highlands



– >1600m
– 15-24°C
– 1300 mm


Robusta, C. canephora
Diploid, self incompatible
Rain forest of Congo basin
– <750m
– 24-30°C
– 1550 mm
Best quality
Susceptible to rust


Less flavor, acidity
Resistant to rust
Tropical Horticulture - Texas A&M University
Two Types of Coffee
About 90 Coffea spp in Africa

Arabica, C. arabica

Robusta, C. canephora

Medium size tree

Medium to large tree
– 14-20’ tall


– Up to 32’ tall
Medium vigor
Leaves


– Smaller
– Thinner

Vigorous
Leaves
– Larger
– Thicker
Seedlings uniform

Seedlings variable
Tropical Horticulture - Texas A&M University
Distribution of Cultivated Coffee
Amsterdam
Paris
1725
Martinique
Yemen
arabica
1700
1690
canephora
1900
1710
Tropical Horticulture - Texas A&M University
Java
Coffee Production and Yield
0.7
0.65
0.6
0.56
0.5
0.42
0.4
0
% Production
MT/ha
Tropical Horticulture - Texas A&M University
Asia
C. Amer
Africa
0.19
Asia
C. Amer
Africa
0.1
0.2 0.19
S. America
0.36
0.3
0.2
0.7
World Coffee Production

Brazil
– 21.1%, arabica
– Only country with frost possibility in coffee
zone

Colombia
– 13.9%, arabica

Indonesia
– 7.3%, robusta

Other important producing countries
– Vietnam, Mexico, Ethiopia, India,
Guatemala, Ivory Coast, Uganda
1996 data from Wilson, 1999. Coffee, Cocoa, and Tea. CABI Publishing.
Tropical Horticulture - Texas A&M University
Major Consumers

High proportion imported by
developed countries
– USA
– EEC
23%
39%
Tropical Horticulture - Texas A&M University
The Seed of the Fruit is the Economic Part
A Drupe like a Peach


Both begin bearing in
3-4 years
Time to mature fruit
– Arabica, 7-8 months
– Robusta, 11-12 months


Productive for 20-30
years
Both need pruning for
best production
Tropical Horticulture - Texas A&M University
The Coffee Fruit is called a Cherry

Exocarp
– Red skin

Mesocarp
– Sweet pulp

Endocarp, hull
– Testa (silvery)
– Bean (embryo and
cotyledons)
Tropical Horticulture - Texas A&M University
The Coffee Fruit is called a Cherry

Exocarp
– Red skin

Mesocarp
– Sweet pulp

Endocarp, hull
– Testa (silvery)
– Bean (embryo and
cotyledons)
– Parchment coffee is the
bean, testa, endocarp
From Wilson, 1999. Coffee, Cocoa, and Tea, CABI Publishing.
Tropical Horticulture - Texas A&M University
Coffee Tree Growth Cycle

Dry and/or cool season
– Floral initiation
– Reduced vegetative growth

Wet season
– Flowers open, fruit set and begin
development
– Active vegetative growth

Dry and/or cool season
– Fruit ripen
– Flower buds initiate
– Reduced Tropical
vegetative
growth
Horticulture - Texas A&M University
Coffee Tree Growth Habit

Orthotropic stem
– Erect growth

Plagiotropic stems
– Horizontal secondary
stems growing off of
orthotropic stems
– These are the fruiting
wood
Tropical Horticulture - Texas A&M University
Coffee Farmers

Grown under many conditions
– Plantations and smaller farmers
– Under shade and in full sun
– Monoculture and mixed farming
systems
Tropical Horticulture - Texas A&M University
Coffee Production

Propagation
– For arabica

Most is done by seed
– Clonal propagation


Hybrids
Robusta types
Tropical Horticulture - Texas A&M University
Coffee Production

Planting
– Slightly acid (pH 5.2 to 6.3) well drained soil
– Beginning of wet season
– Vertical position or 30° angle

Spacing - need light for fruit ripening
– Arabica, 1350 trees/ha
– Robusta, 900-1000 trees/ha

Time to fruiting
– Take 3-4 years to obtain mature plant
– Fruit on year old wood
Tropical Horticulture - Texas A&M University
Shade and Coffee Production

Both species are understorey trees
– Well adapted to shade
– Initially coffee was planted under
shade
– Small holders may use mixed farming

Later unshaded plants were shown
to produce higher yields
Tropical Horticulture - Texas A&M University
Shade and Coffee Production
8
7
6
5
4
3
2
1
0
Fertilized
No fertilizer
Shaded
Unshaded
Data from Wilson, 1999. Coffee, Cocoa, and Tea, Figure 6.4.
Conclusion:
High input system - better with fertilizer
Low input system - not as essential
Tropical Horticulture - Texas A&M University
Coffee Production

Training/Pruning objectives
– Maximize # plagiotrophic stems
(fruiting wood)
– Shape trees


Maximize use of space
Ease of management
– Maintain open tree to allow good light
penetration
– Minimize biennial bearing
– Remove diseased and dead wood
Tropical Horticulture - Texas A&M University
Single Stem Training
(Central leader)

Cut back orthotropic stem
– Encourages plagiotropic
stem formation

Repeat for 3-5 years
– With each cycle the tree gets
bigger
– Lower limbs die due to lack
of light

Rejuvenate after 3-5 years
– To reduce size of tree
– Cut back to 40-50 cm height
Tropical Horticulture - Texas A&M University
Single Stem Training
(Central leader)

Cut back orthotropic stem
– Encourages plagiotropic
stem formation
– Select one orthotropic as
new leader

Repeat for 3-5 years
– With each cycle the tree gets
bigger
– Lower limbs die due to lack
of light

Rejuvenate after 3-5 years
– To reduce size of tree
– Cut back to 40-50 cm height
Tropical Horticulture - Texas A&M University
Single Stem Training
(Central leader)

Cut back orthotropic stem
– Encourages plagiotropic
stem formation
– Select one orthotropic as
new leader

Repeat for 3-5 years
– With each cycle the tree gets
bigger
– Lower limbs die due to lack
of light

Rejuvenate after 3-5 years
– To reduce size of tree
– Cut back to 40-50 cm height
Tropical Horticulture - Texas A&M University
Multiple Stem Training
(Modified Central Leader)


Leave 2-8 orthotropic stems
Pruning
– Cut back (or bend) orthotropic
stem
 Encourages orthotropic
stem formation
 Select several orthotropic
stems to be new leaders
– Eliminate growth in center of
tree
Tropical Horticulture - Texas A&M University
Multiple Stem Training
(Modified Central Leader)


Leave 2-8 orthotropic stems
Pruning
– Eliminate growth in center
of tree
– Continues growing taller
– Cropping area moves higher
Tropical Horticulture - Texas A&M University
Multiple Stem Training
(Modified Central Leader)


Leave 2-8 orthotropic
stems
Pruning
– Cut out wood in center
– Continues growing taller
– Cropping area moves
higher

Rejuvenation every 4-6
years
– Need to lower fruiting
surface
– Allow basal suckers to
grow
Tropical Horticulture - Texas A&M University
Multiple Stem Training
(Modified Central Leader)

Rejuvenation every 4-6
years
– Allow suckers to grow

Remove old branches
– Stump with “lung”

Once suckers begin to
grow remove “lung”
Tropical Horticulture - Texas A&M University
Harvest

Most done by hand
– Ripe berries only

Pick every 8-10 days
– In Brazil, allow cherries
to dry on tree

Machine harvest in
Brazil
– Oscillating fingers
– 7-9% immature fruit
From Wilson, 1999. Coffee, Cocoa, and Tea, CABI Publishing.
Tropical Horticulture - Texas A&M University
Disease and Pests Problems

Losses due to diseases
– Africa
– Asia
– S. Am.

15%
10%
12%
Coffee rust (Hemeleia vastatrix)
– History


First in Sri Lanka in 1880
Now throughout world
– Control




Robusta/hybrids resistant
Less serious above 1700 m
Cu fungicides
Coffee Berry Disease (Colletotrichum)
– Cause berry rot
Tropical Horticulture - Texas A&M University
Disease and Pests Problems

Losses due to pests
– Africa
– Asia
– S. Am.

20%
15%
15%

Insert Fig
8.4, p 87
Coffee Berry Borer
– History


Originate in Africa
Now throughout world
– Damage

Larvae feed on bean
– Control




From Wilson, 1999. Coffee, Cocoa, and Tea, CABI Publishing.
Berry removal
Chemicals
IPM
Monkeys, birdsTropical Horticulture - Texas A&M University
Coffee Processing
Bean Processing done on the
Farm
Wet Method

Start on Harvest Day
– Separate trash and defective berries
by flotation
– Good berries are depulped same day

Fermentation
– Only to remove mucilaginous
covering
– Excessive heat destroys flavor
Tropical Horticulture - Texas A&M University
Wet Method

Washed
– Water under pressure

Dried - spread out to
dry
– Sun
– Artificial heat

Best quality
– Gives coffee that is cleaner,
brighter, fruitier, better acidity
Tropical Horticulture - Texas A&M University
Dry Method (Natural Method)
(Most traditional and least expensive)

Drying (Indonesia, Ethiopia, Brazil, Yemen)
– Initial drying done on trees
– Spread on concrete, tile or matted
surface



2” thick and constantly raked
3-15 days until specific moisture
Pergamino is dry and crumbly
Tropical Horticulture - Texas A&M University
Dry Method
(Most traditional and least expensive)




Remove pericarp
– Mortar and pestle or machine
Chaff removed via winnowing and picking
Sorted by size, shape, density and color
Packed in 60 kg bags for processing
Tropical Horticulture - Texas A&M University
Industrial Processing
(Usually by importing company)

Grading process
– Redry and clean the parchment beans before using
– Remove testa (hulling and polishing)
– Sort on size and density

Roasting (370°F to 540°F)
– Removes moisture


Light roast lose 3-5% moisture
Dark roast lose 8-14% moisture
– Time (up to 30 min) determines flavor

Decreasing the amount of
– Chlorogenic acid
– Trigonelline

Grinding
Tropical Horticulture - Texas A&M University
Industrial Processing
(Usually by importing company)

Caffeine Reduction
– Add water to beans
– Extract with


Methylene chloride and ethyl acetate
Residual solvent removed via low level
steam drying
– Caffeine can be recovered with
water extraction of organic solvent
Tropical Horticulture - Texas A&M University
Industrial Processing
(Usually by importing company)


Once ground the beans lose flavor
rapidly
Grinding
– Coarse to medium (600-1100 μm)

Home percolators
– Fine grinds (Automatic percolators)

Europe (400-500 μm)

USA (600-700 μm)
Tropical Horticulture - Texas A&M University
Industrial Processing
(Usually by importing company)

Instant Coffee
– Extract soluble solids, volatile aroma and
flavor with water

Drying
– Drum drying - poor appearance
– Spray drying - loses flavor volatiles
– Freeze drying - best product




Best retention of flavor
Produces granules
No evaporation so no loss of flavor
Coffee oil for head space aroma
Tropical Horticulture - Texas A&M University
Any Questions?